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Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_615_Библиотеки_им_академика_М_И_Перельмана

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LARGE BOWEL
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Criteria for close surveillance after endoscopic removal of a malignant polyp include complete excision, a microscopic margin greater than 2 mm, no lymphatic or vascular invasion, moderate to well differentiation, Haggitt level 1 to 3, or Sm level 1 to 2.
All other malignant polyps that do not meet the aforementioned criteria should be considered for surgical resection. However, even with some high-risk features, patients with serious medical comor­bidities may be best managed with close surveillance and nonsurgical treatment. An alternative to patients at high risk with a malignant rectal polyp may be full-thickness surgical excision (TAE, TEM, or TAMIS) with adjuvant chemoradiation.
Management of Peritoneal Surface Malignancies
Fabian M. Johnston, MD, and Juliet Siena Lumati, MD
eritoneal surface malignancies represent a heterogenous group of intraperitoneal malignancies arising from the lining of the
P
abdominal and pelvic cavity. They include primary malignancies of the peritoneum such as diffuse malignant peritoneal mesothelioma, peritoneal serous papillary carcinoma, desmoplastic small round cell tumors, and metastases from other primary tumors typically involving the colon, stomach, and ovaries. Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) have evolved over the past decade to provide a therapeutic advantage to patients who otherwise have limited options beyond systemic chemoradiation for locoregional control or palliation. The purpose of this chapter is to review the epidemiology of peritoneal surface malignancies as well as current treatment guidelines.
EPIDEMIOLOGY AND CLASSIFICATION
Appendiceal Neoplasm
The true incidence of appendiceal neoplasms is unknown but is thought to be about 0.12 cases per 100,000 people per year in the United States. They are more commonly diagnosed incidentally on pathology in about 1% to 2% of appendectomy specimens. These tumors can be of mucinous or non-mucinous histology and may contain a signet ring cell component. Signet ring cell carcinomas are very aggressive, with up to 60% of cases already showing distant metastasis at the time of diagnosis. Patients with mucinous tumors may clinically present with pseudomyxoma peritonei (PMP), which is a condition characterized by mucinous ascites and peritoneal implants. Because of the rarity of these neoplasms, histologic clas­sification had been challenging until 2010, when the World Health Organization recognized three categories of primary appendiceal neoplasms: mucinous adenoma, low-grade appendiceal mucinous neoplasm (LAMN), and mucinous adenocarcinoma. Subsequently in 2016, The Peritoneal Surface Oncology Group International Consensus developed a classification system to describe both the primary lesion and peritoneal disease. It also classified noncar­cinoid epithelial neoplasms of the appendix itself and added a new term, high-grade appendiceal mucinous neoplasm (HAMN) for lesions with the low-grade architectural features of low-grade appendiceal mucinous neoplasm but with high-grade cytologic features (Box 1).
S u g g e S t e d R e a d i n g
Leggett B, Whitehall V. Role of the serrated pathway in colorectal cancer
pathogenesis. Gastroenterology. 2010;138:2088–2100.
Rai V, Mishra N. Transanal approach to rectal polyps and cancer. Clin Colon
Rectal Surg. 2016;29(1):65–70.
Shaukat A, Kahi CJ, Burke CA, Rabeneck L, Sauer BG, Rex DK. ACG Clinical
Guidelines: Colorectal Cancer Screening 2021. Am J Gastroenterol. 2021;116(3):458–479.
Wickham CJ, Wang J, Mirza KL, et al. “Unresectable” polyp management
utilizing advanced endoscopic techniques results in high rate of colon preservation. Surg Endosc. 2022;36(3):2121–2128.
CLINICAL MANIFESTATION
Clinical symptoms on presentation can be quite nonspecific. Com­mon presentations include increasing abdominal girth, weight loss, fatigue, bloating, constipation, and pain. Not uncommonly the diag­nosis is made on presentation with acute appendicitis obstruction of the appendiceal lumen by malignant cells, which may lead to inflammation and infection of the appendix. Similarly, mucinous tumors may present with cystic dilation of the appendix, which could also mimic symptoms of appendicitis or be found incidentally on imaging for a different etiology. Men may also present with hernias and women with a bulky pelvic mass. Anorexia, early satiety, and massive ascites are also common manifestations, and in some ways, likely underestimate the true incidence of the disease given the late clinical presentation of these neoplasms.
PREOPERATIVE WORKUP
Preoperative workup should include staging CT of the chest, abdo­men, and pelvis. Routine CBC, basic metabolic panel, and nutritional markers are often helpful. Other parameters include serum tumor markers including CEA, CA 19-9, CA125, and chromogranin A as well as obtaining a preoperative colonoscopy to evaluate for syn­chronous or metachronous colonic lesions, which at times may be negative. A diagnostic laparoscopy may be useful in determining eli­gibility for cytoreductive surgery in addition to obtaining histologic assessment, which may help guide treatment plans.
PATIENT SELECTION
Patient selection is extremely important in deciding who will most benefit from CRS and HIPEC and to avoid significant morbidity and mortality in patients who are not expected to benefit. Surgeons
BOX 1 PSOGI 2016 Classification of Noncarcinoid
Appendiceal Epithelial Neoplasms
• Tubular,tubulovillousorvillousadenoma,low-orhigh-grade
dysplasia
• Serratedpolypwithorwithoutdysplasia(loworhighgrade)
• Low-gradeappendicealmucinousneoplasm
• High-gradeappendicealmucinousneoplasm
• Mucinousadenocarcinoma:well,moderately,orpoorly
differentiated
• Poorlydifferentiated(mucinous)adenocarcinomawithsignet
ring cells
• (Mucinous)signetringcellcarcinoma
• Adenocarcinoma:well,moderately,orpoorlydifferentiated
268 MANAGEMENT OF PERITONEAL SURFACE MALIGNANCIES
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should consider the extent of disease, tumor biology, physiologic age, comorbidities, and the ECOG/WHO functional and frailty status when selecting patients. Scoring systems such as the peri­toneal disease severity score (PDSC), which was devised to stage patients with colon cancer based on clinical symptoms, extent of carcinomatosis based on radiographic evidence, and tumor histo­pathology may be useful to facilitate appropriate patient selection. For patients with LAMN (grade 1) CRS + HIPEC is the treatment of choice if complete cytoreduction can be achieved. Patients with adenocarcinoma and peritoneal metastasis are less likely to have complete cytoreduction and overall have poorer survival than those with LAMN. It is important to note that not all LAMNs or well-dif­ferentiated mucinous adenocarcinomas require a right hemicolec­tomy unless there is clear involvement of the colon serosa, which would necessitate colectomy. Furthermore, The American College of Surgeons’ NSQIP surgical risk calculator may also be used to estimate perioperative risk, especially in patients with significant cardiopulmonary comorbidities not captured by the PDSC. It is important to note that no risk calculator is absolute; therefore, it is the combination of risk factors and expected net benefit that guides preoperative discussions with patients to set appropriate expecta­tions. Furthermore, all patients should be presented at multidisci­plinary team with considerations given to probability of extensive organ resection, morbidity, quality of life, and recurrence risk. The Chicago Consensus Guidelines on the management of appendiceal neoplasms are highlighted in Figures 1 and 2.
COLORECTAL CANCERS
The care of patients with advanced colorectal cancer has evolved over the past several decades, with overall improvement in the median survival
for patients with stage IV disease. This has been largely attributed to improvements in the use of multimodal targeted therapy (i.e., neoadjuvant chemotherapy [NACT] and chemoradiation for rectal tumors), surgical technique, adjuvant chemotherapy for colon cancer, and improved patient selection. This is in addition to improving evidence that metastasectomy of liver and lung metastases improves 5-year survivorship.
In 2003, Verwall et al. randomized 105 patients with metastatic colon cancer with peritoneal carcinomatosis to receive CRS + HIPEC or systemic therapy alone that consisted of monotherapy 5FU/leu­covorin. Results from this clinical trial showed an improvement in median survival in the HIPEC arm at 22.3 months compared with 12 months in the standard group at the median follow-up of 22 months. However, a subsequent follow-up study published in 2008 found no difference at the 8-year follow-up. Similarly, the COLOPEC trial, which was a multicenter randomized controlled trial (RCT) of 204 patients compared adjuvant HIPEC + systemic chemotherapy to systemic chemotherapy alone. The authors found no difference in metastasis-free survival at 18 months and a slight increase in post­operative complications in the HIPEC + chemotherapy group. Given that HIPEC is typically performed concurrently with CRS, the first study to evaluate HIPEC + CRS versus CRS alone was the PRODIGE trial with results recently published as of February 2021. This was an RCT comparing HIPEC + CRS versus CRS alone and recruited 265 patients across 7 centers. The authors found no significant difference in the median survival in the HIPEC + CRS group versus the CRS group (41 months vs. 40 months, respectively) at a median follow-up of 63 months. In a subgroup analysis, patients with a moderate bur­den of peritoneal disease (peritoneal cancer index [PCI] 11–15) who received HIPEC had a significant improvement in overall survival at 41 months compared with 32 months in CRS, though outpatient complication rates were higher in the HIPEC + CRS group versus
Low-Grade Appendiceal Mucinous Neoplasm
(LAMN)
*A positive appendiceal margin should be addressed with conservative
of the appendiceal cuff or partial cecectomy, avoiding if possible an anastomosis.
Routine right hemicolectomy is discouraged.
†A small percentage of tumors with low-grade histopathology will present
with high-grade peritoneal disease. These should be treated as high-grade
primary tumor.
No Evidence of
Peritoneal
Spread
Peritoneal
Negative
Margin
Positive
Margin
Cecectomy or
IIeocecectomy*
Surveillance if
Perforation
Observation,
Consider
Diagnostic
Laparoscopy
IPCT
Observation,
Consider
Diagnostic
Laparoscopy
CRS + IPCT
Progressive
or Recurrent
Disease
Interval < 1 y
Interval > 1 y
Noninvasive
Pathology
Invasive
Pathology
Consider
Pathology
Review
Observation
Consider
Clinical Trial
Consider CRS
+/– IPCT
Appendiceal
Adenocarcinoma
Guidelines
Repeat CRS
+/– IPCT
FIG. 1 The 2018 Chicago Consensus Guidelines on the Management of Low-Grade Appendiceal Mucinous Neoplasm (LAMN). (From Chicago Consensus
Working Group.The Chicago consensus on peritoneal surface malignancies: standards. Cancer.2020;126:2516–2524.)
R: Right
Appendiceal Adenocarcinoma
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Incidental
Finding
After
Appendectomy
Biopsy
(if Possible)
Found on
Imaging or
Colonoscopy
Appendiceal
Adenocarcinoma
H&P
CT C/A/P or MRI
A/P and CT
Chest,
CEA, CA19-9,
CA125, CRP,
Consider
Colonoscopy
Tumor Board
Consultation
Concerning
Radiologic
Features/
Laparoscopic
Evidence for
Peritoneal
Disease
Extraperitoneal
Disease
Consider
Clinical Trial or
Systemic
Therapy
Complete
Cytoreduction
Predicted
Incomplete
Cytoreduction
Predicted
Reassess for
Response
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CRS + IPCT (Well-Differentiated Preferred)
Selective R Hemicolectomy*
CRS + IPCT
R Hemicolectomy
3 mo
Systemic Therapy
6 mo
Systemic
Therapy 3-6 mo
Node Positive
Systemic Therapy
6 mo
CRS + IPCT
R Hemicolectomy
CRS + IPCT
R Hemicolectomy
Progression
Response/
Complete CRS
Predicted
Systemic Therapy 3 mo
Second-Line Chemotherapy/
Clinical Trial/
Best Supportive Care
CRS + IPCT
R Hemicolectomy
Consider Systemic
Chemotherapy
269
Systemic
Therapy 3 mo if
Received 3 mo
Prior to CRS
*If well-differentiated mucinous adenocarcinoma pathology
is confirmed by expert pathologist, then observation may be
considered (no R hemicolectomy). High-grade appendiceal
mucinous neoplasms and well-differentiated mucinous
adenocarcinoma may be treated similar to low-grade lesions.
CA19-9: Carbohydrate Antigen 19-9 CA125: Cancer Antigen 125CEA: Carcinoembryonic Antigen CRP: C-reactive Protein CRS: Cytoreductive Surgery CT C/A/P: Computed Tomography of Chest/Abdomen/Pelvis H&P: History and Physical IPCT: Intraperitoneal Chemotherapy MRI A/P: Magnetic Resonance Imaging of Abdomen/Pelvis
No Metastatic
Disease
peritoneal disease (cytology/gross),
consult “Peritoneal Disease” pathway
Right
Hemicolectomy*
If any intraoperative concern of
above
Node Negative Observe
FIG. 2 The 2018 Chicago Consensus Guidelines on the Management of Appendiceal Adenocarcinomas. (From Chicago Consensus Working Group.The Chicago
consensus on peritoneal surface malignancies: standards. Cancer.2020;126:2516–2524.)
the CRS group (24% vs. 13%, respectively). The results of these studies on prospective clinical trials highlight the need for a mul­tidisciplinary approach to selecting patients who will maximally benefit from CRS versus HIPEC+ CRS. It also highlights the benefit of cytoreduction in combination with NACT.
should include a thorough history and physical examination along with axial imaging including CT of the chest, abdomen, and pelvis. PET/CT may be useful in patients with non-mucinous tumors. Lab­oratory workup includes CEA, CA-19, and CA-125 levels and nutri­tional markers. A complete colonoscopy is also recommended if not already completed. Diagnostic laparoscopy may be helpful for staging
Epidemiology
Peritoneal disease is present in about 8% of CRC patients at the time of primary resection, and up to 25% of patients with recurrent CRS will develop metastatic disease confined to the peritoneal surface. Risk factors for peritoneal metastases include mucinous histology, T4 cancers, vascular invasion, spontaneous or iatrogenic perforation, and right-sided tumors, which overall confer a worse prognosis. The presence of untreated visceral solid organ metastasis is a relative contraindication to HIPEC and CRS.
and assessment of surgical eligibility given the poor sensitivity of axial imaging for detecting peritoneal metastasis. In addition, small tumors in specific locations such as the root of the mesentery and serosal sur­face of the small bowel are harder to detect on CT scan. PET/CT has a sensitivity of 78% to 100% and is not uncommonly ordered before sur­gery. It is however associated with false-negative results for tumors that are not PET/CT avid (mucinous tumors) or false-positive results for inflammatory processes. There have been limited studies evaluating the role of diffusion weight MRI in detecting subcentimeter deposits in difficult anatomic locations, though it is not widely adopted given the contraindications, costs, and availability.
Clinical Manifestations
Peritoneal metastases secondary to CRC may present with ascites manifesting as increasing intraabdominal girth, pain, or small bowel obstruction. However, just as often, synchronous peritoneal disease may be asymptomatic and detected at the time of primary surgery or on staging imaging. For patients with metachronous disease, it is most common to identify peritoneal metastases during surveillance given the intensity of imaging use in current practice.
Preoperative Workup
Patient selection is very important in determining the appropriate­ness of cytoreductive surgery and HIPEC. Preoperative evaluation
Patient Selection for Surgery
Patient selection is critical in determining who would most benefit from CRS + HIPEC. Generally, good candidates for CRS + HIPEC are patients with good performance status who have an ECOG/WHO status of 1 or less, have adequate physiologic and organ function, have a low/moderate PCI, and can receive systemic chemotherapy. In fact, response to initial chemotherapy is often used as prognostic marker to screen patients with rapidly evolving tumor biology. PCI scores range from 0 to 39, with a score less than 12 considered most favorable for resection. A PCI greater than 20 is typically considered a contraindication to resection. Patients with a PCI between 12 and 20 may be determined on a case-by-case basis depending on
270 MANAGEMENT OF PERITONEAL SURFACE MALIGNANCIES
PET: Positron Emission Tomography
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Colorectal Cancer with Synchronous Peritoneal Metastasis
Newly Diagnosed
Colorectal Adenocarcinoma with Peritoneal Metastasis
Synchronous
H&P
CT C/A/P +/–MRI +/– PET
Complete Colonoscopy
with Biopsies
Pathology Review
Determine MSI, KRAS,
and BRAF Status
Pelvic MRI for Rectal
Cancer
CEA
Tumor Board
Consultation
CEA: Carcinoembryonic Antigen CT C/A/P: Computed Tomography of Chest/Abdomen/Pelvis CRS: Cytoreductive Surgery H&P: History and Physical IPCT: Intraperitoneal Chemotherapy MRI A/P: Magnetic Resonance Imaging of Abdomen/Pelvis MSI: Microsatellite Instability PCI: Peritoneal Carcinomatosis Index
Peritoneal
Metastases
Only*
Widespread and/or
Unresectable Solid-
Organ Metastases
Patients with Resectable Liver and/or
Lung Metastases in the Context of
Associated
CRS +/– IPCT for
Selected Patients with
Low PCI
Chemotherapy for
3–6 mo
+/– Chemoradiotherapy
for Rectal Cancer
*Refer to Principles of Surgery for
Peritoneal Metastasis
Consider Palliative Surgery for
Symptomatic Patients
Restaging
Imaging
Systemic Chemotherapy
Best Supportive Care or
Clinical Trial
No
Progression
Progression
Consider
Diagnostic
Laparoscopy
Assess PCI,
Obtain
Biopsies as
Needed
Complete
Cytoreduction
Predicted
Incomplete
Cytoreduction
Predicted
Complete
Cytoreduction
Predicted
Incomplete
Cytoreduction
Predicted
CRS +/– IPCT
Finish First-Line or
Second-Line
Chemotherapy
Best Supportive Care
or Clinical Trial
Consider CRS +/– IPCT
Second-Line
Chemotherapy (Preferred) or Best Supportive Care or
Clinical Trial
Consider
Immunotherapy for
Patients with MSI-
High Tumors
Chemotherapy
(Total 6 mo),
Then Follow-Up
Reassess for
Potential CRS
Chemotherapy
(Total 6 mo),
Then Follow-Up
Reassess for
Potential CRS
FIG. 3 The 2018 Chicago Consensus Guidelines on the Management of Colorectal Cancers with Synchronous Peritoneal Metastasis. (From Chicago
Consensus Working Group.The Chicago consensus on peritoneal surface malignancies: standards. Cancer.2020;126:2516–2524.)
additional clinical parameters, such as extent of extraperitoneal metastasis and tumor biology. A more conservative PCI cutoff of 17 has been proposed based on results of a prospective study by Goere
young age, and female gender. Prognosis of untreated gastric cancer with peritoneal carcinomatous is quite poor, with a median 5-year
survival that approaches 0%. et al., which showed no benefit of HIPEC + CRS in patients with a PCI greater than 17. It is important to note that a preoperative radiologic PCI score may not always correlate with an intraopera­tive PCI score, hence staging laparoscopy can be used as an adjunct to assess borderline cases. The presence of malignant ascites, large tumor burden, or multifocal bowel obstructions are relative con­traindications to curative intent surgery in addition to the presence of liver or lung metastasis that are untreated. Visceral metastases should be considered for therapy on an individualized basis. Lastly, the treatment options and timing for patients with synchronous or metachronous lesions similar to appendiceal neoplasms should be discussed among a multidisciplinary team. Figure 3 summarizes the Chicago Consensus Guidelines on CRS and HIPEC in colorec­tal cancers.
Preoperative Workup
Preoperative workup includes history and physical examination,
upper endoscopic ultrasound, and endoscopic ultrasound with
biopsy for local regional staging. Imaging includes CT of the
chest, abdomen, and pelvis with contrast and PET/CT if there is
no evidence of M1 disease. HER2/NEU testing should be obtained
if metastatic disease is suspected. Molecular profiling to assess
for microsatellite stability and PDL1 positivity maybe helpful for
patients with unresectable disease. Genetic counseling is recom-
mended in young patients to evaluate for CDH1 mutations given
their high penetrance. Nutritional markers should be considered
in addition to smoking cessation and counseling. Patients typically
receive the most commonly used perioperative chemotherapy,
GASTRIC CANCER
Epidemiology and Clinical Manifestation
Gastric cancer is a leading cause of cancer-related deaths, with a mortality rate of 8.9% after lung cancer (19.7%) and breast cancer (12.9%), respectively. Overall 5-year survival approaches 90% in
which includes FOLFOX, XELOX, FLOT, ECF, +/– radiation for 3
to 6 months followed by restaging and diagnostic laparoscopy with
peritoneal washings. Patients with advanced tumors, clinical T3
or greater, or node-positive disease should undergo laparoscopic
staging with peritoneal washings to evaluate for extent of peritoneal
disease. countries like Japan and varies between 10% and 30% in Western countries. Peritoneal carcinomatosis occurs synchronously with primary tumors in 14%% to 43% of patients with gastric cancer and accounts for 35% of synchronous metastasis. Risk factors for perito­neal metastasis include extranodal involvement, diffuse infiltrated type, signet cell histology, higher CEA levels, liver involvement,
Patient Selection for Surgery
All patients with biopsy-proven gastric cancer should be presented
to a multidisciplinary tumor board to discuss a tailored treatment
plan, which is largely dependent on the patient’s functional status and
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271
tumor biology. Generally, patients with low peritoneal disease burden and lack of progression of disease after systemic therapy should be restaged and considered for HIPEC + CRS. Various options include early postoperative chemotherapy (EPIC) or bidirectional intraperi­toneal and systemic induction chemotherapy before CRS + HIPEC. Ideal candidates should be young (<70 years of age) and have a good performance status, a PCI score <10, small nodules, a resectable pri­mary tumor, no evidence of paraaortic lymphadenopathy, no liver or extraperitoneal metastasis, and have responded well to NACT.
Hoptopp et al. found an overall increase in survival in patients with gastric cancer and confirmed peritoneal metastasis who underwent NACT with FLOT followed by CRS + HIPEC versus chemotherapy alone (17 months vs. 6 months) in a single-center study. A more recent advancement is the use of neoadjuvant intra­peritoneal and systemic chemotherapy protocol/bidirectional intra­peritoneal and systemic induction chemotherapy (NIPS/BISIC), which aims to reduce the stage and increase the incidence of com­plete cytoreduction. By simultaneously administering intravenous and intraperitoneal chemotherapy, the cancer cells are targeted both from the peritoneal cavity and subperitoneal blood vessels. Several studies have examined the effectiveness of this therapy in complete cytoreduction and improving survivorship. Yonemura et al published a prospective study of 194 patients who had BIPSC followed by CRS + HIPEC. Patients had (1) biopsy-proven perito­neal carcinomatosis, (2) no evidence of liver or lung metastasis, and (3) good performance scores. In this study, 152 patients responded to BIPSC and subsequently underwent CRS + HIPEC. Complete cytoreduction was achieved in about 70% of these patients. Median survival was 15.8 months in patients who had CRS + HIPEC after BIPSC versus patients who did not (7 months). Completeness of cytoreduction, pathologic response to NIPS, and PCI on multivar­iate analysis overall predicted survivorship. It is important to note that the complication rate was 24%, which is similar to that found in a study by Hultman et al., which also showed an improvement in median survivorship (19 months vs. 14 months) but reported a higher complication rate of 63%. This is most commonly caused by anastomotic leak, sepsis, wound infections, and organ failure. These studies show that appropriate patient selection and identi­fication of patients with unresectable or disseminated disease who are eligible for complete cytoreduction is paramount.
PERITONEAL MESOTHELIOMA
Epidemiology and Clinical Manifestation
Mesothelioma is a rare malignancy of serosal membranes. This includes the pleura, peritoneum, pericardium, and the tunica vag­inalis testes.The peritoneum is the second most common location and is estimated to represent about 10% to 15% of all mesothe­liomas. The highest incidence is reported in countries such as New Zealand, the United Kingdom, and Australia, and the lowest incidence is reported in countries such as Japan, Slovenia, and Central Europe. The estimated incidence is 1.94 per 100,0000 and
0.41 per 100,000 for men and women, respectively, in the United States. Mesothelioma is commonly associated with exposure to asbestos, but 33% to 50% of patients diagnosed with malignant pleural mesothelioma (MPM) have no prior asbestos exposures. Other risk factors include exposure to radiation minerals such as thorium, chronic peritonitis, and germline BRCA-1–associated protein (BAP-1) gene mutation. Histologic classifications include epithelioid, sarcomatous, and biphasic/mixed. About 75% of all mesotheliomas are epithelioid in origin, which overall have the most favorable prognosis.
Perioperative Workup
Making the diagnosis is often challenging as patients present with mostly vague abdominal symptoms. On imaging, patients may
have ascites, evidence of omental caking, or mesenteric fatty infil­tration. Definitive diagnosis is based on histology and pathologic assessment, which could be obtained on percutaneous biopsy or diagnostic laparoscopy. Diagnostic laparoscopy is indicated to evaluate the extent of disease amenable to surgery. Pathologic assessment is essential to differentiating subtypes of mesotheli­oma that may be more amenable to surgery versus chemother­apy alone. Epithelioid histology has overall the most favorable response to HIPEC + CRS in contrast with sarcomatoid, biphasic subtypes, which overall have a poorer prognosis and for which surgery is less likely to offer a survival benefit. Furthermore, the CA-125 and Ki-67 index are often obtained in addition to germ­line testing for a BAP-1 gene mutation.
Patient Selection for Surgery
The natural history of MPM is aggressive; without treatment, median survival is approximately 6 months. Median survival with systemic chemotherapy alone is approximately 16 months; how­ever, it improves to approximately 40 months with HIPEC + CRS. Patients with MPM are considered for surgical therapy with CRS/ HIPEC if their disease burden is amenable to resection of all or nearly all (CC-0 or CC-1) visible disease and are suitably fit for such extensive resection.
OVARIAN CANCER
Epidemiology and Clinical Manifestation
Ovarian cancer is associated with one of the highest mortalities from gynecologic cancers in the world, with an estimated 5-year survival rate of 39%. Despite efforts to screen for ovarian cancer, 35% to 43% of patients still present with advanced disease involving the peritoneum at the time of diagnosis. Risk factors for peritoneal disease include germline mutations, incomplete resection at initial cytoreductive surgery, shorter treatment-free survival, higher FIGO (International Federation of Gynecology and Obstetrics) stage, and the present of malignant ascites. The most common type of ovarian cancer is epithelial in origin; less common types include clear cell, mucinous, carcinosarcoma, endometroid carcinoma, and malignant germ cell tumors. Symptoms include early satiety, bloating, nonspe­cific abdominal pain, and urinary symptoms. Others may present with massive ascites, which is typically associated with mucinous neoplasms.
Preoperative Workup
The diagnosis is made based on clinical suspicion, imaging, and tumor markers, with elevation of CA-125, inhibin, B-HCG, LDH, and CEA levels being pathognomonic. Nutritional parameters, CBC, and liver function tests and chemistries are routinely ordered. A complete colonoscopy is recommended to evaluate for synchronous gastrointestinal malignancies that can present similarly. Genetic counseling is recommended for all patients given the incidence of BRCA mutation, which may help guide adjuvant systemic therapy. Surgery is the mainstay therapy and typically includes extensive debulking and cytoreduction with a total abdominal hysterectomy and bilateral salpingo-oophorectomy (TAH + BSO) but can include appendectomy, colon or small bowel resection, cholecystectomy, and omentectomy. Diagnostic laparoscopy is essential to quantify tumor burden and identify patients whose disease is amenable to adequate cytoreduction. The presence of omental caking, peritoneal and dia­phragmatic extensive carcinomatosis, mesenteric retraction, bowel and stomach infiltration, and spleen and/or liver superficial metas­tasis are typically assessed on laparoscopy. Importantly, these oper­ations are typically conducted using a multidisciplinary approach involving gynecology oncology and surgical oncology to improve the chances of complete cytoreduction.
272 MANAGEMENT OF PERITONEAL SURFACE MALIGNANCIES
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Patient Selection for Surgery
HIPEC is typically considered in patients with stage III disease of epithelial origin as the other cell types are less chemosensitive. Fur­thermore, NACT with interval CRS is considered in patients with advanced-stage ovarian cancer who are not good candidates for upfront primary debulking surgery (PDS) because of advanced age, frailty, poor performance status, or for those in whom the disease is unlikely to be optimally cytoreduced. This has the potential to facilitate medical optimization and to downstage the disease. The addition of HIPEC to CRS has been evaluated in several studies in the recurrent setting. In a 2015 RCT, Spilotis found a 13-month improvement in survival with HIPEC + CRS versus CRS alone. In a retrospective cohort study of 584 patients with stage III epithelial ovarian cancer, Lei et al. found an overall 15-month improvement in survival in patients undergoing CRS + HIPEC versus CRS alone, and patients with complete CRS had the most favorable survival outcomes. In an RCT of 245 patients randomized to HIPEC + CRS versus CRS alone, Van Driel et al. found an increase in overall median survival in the HIPEC + CRS group at 45.7 months versus
33.9 months in the CRS group alone. The CHIPPI-1808 trial com­paring HIPEC + NACT + CRS versus NACT + CRS should have results by 2026 and perhaps may help improve patient selection and justify the use of upfront HIPEC in the primary setting versus the current standard of care, which is typically in the recurrent setting with interval CRS.
Intraoperative Management and Technique
The Chicago Consensus Working group publishes a consensus on peritoneal surface malignancies that includes guidelines for standard operations and metrics. Generally speaking, a fellowship experience with CRS + HIPEC, documentation of number of cases, and availability of two surgeons are necessary in addition to established criteria for institutional credentials. Process stan­dards include confirmed tissue diagnosis, relevant tumor markers depending on the cancer type, cross-sectional imaging, and ideally registry of all patients in a data repository. Quality standards also exist for reporting of pathology, intraoperative monitoring, per­fusion equipment used, and rating of the completeness of intra­operative cytoreduction. A complete list of standards, quality, and process measures is available online.
Preoperatively patients undergo mechanical bowel preparation with oral antibiotics before surgery. Patients are positioned supine for lithotomy if any concern of needing lower pelvic work; DVT prophylaxis with SCDs and subcutaneous heparin in addition to perioperative IV antibiotics are administered. It is important to maintain good communication with anesthesia and the intraopera­tive room staff to ensure that the patient’s core body temperature is maintained and that the patient is adequately being resuscitated to maintain good urine output given insensible losses that can occur during the operation. Adequate monitoring of cardiovascular and fluid resuscitation is crucial in the intraoperative and postoperative period. If not closely monitored and managed, patients are at risk for abdominal hypertension, coagulopathy, decreased systemic vascular resistance, and high-output cardiac failure in addition to toxicities directly related to the chemotherapy agent being used. Therefore, early determination of the need for recovery in the intensive care unit (ICU) should be determined intraopera­tively. Increasingly, intraoperative goal-directed fluid therapy and enhanced recovery pathways have been implemented in various institutions with the goal to improve postoperative outcomes. For example, tools such as stroke volume variation are used to guide fluid management and maintain urine output. This strategy overall leads to less overall fluid administration and is associated with less postoperative morbidity.
The procedure begins with an exploratory laparotomy with complete evaluation of the extent of peritoneal metastasizes and
probability of complete cytoreduction through a midline incision. Diagnostic laparoscopy may be undertaken before laparotomy if there is concern that the extent of disease may preclude cytoreduc­tion. Lysis of adhesions may be required if the patient already had prior surgeries or malignant adhesions that may preclude safe entry. A pre-cytoreduction PCI is assessed followed by complete cytoreduc­tive surgery with the intent of removing all tumors greater than 0.25 cm. (CC-0 or CC-1). We generally inspect systematically the bilateral diaphragm surfaces, lesser sac, small bowel and its mesentery, porta hepatis, aortocaval groove (IVC bursa) near the caudate and pelvis, and all solid organs. Once all sites have been inspected, we recom­mend running the small bowel in its entirety from the ligament of Treitz to the ileocecal valve as well as inspecting the right and left colon and its mesentery to the level of the sacral promontory. All prior anastomoses should also be inspected in addition to incising the nodal tissue at the ligament of Treitz, falciform ligament, and triangular ligament for liver mobilization. Small lesions can be removed sharply, but larger lesions that are infiltrative or cannot be separated easily require formal resection. Generally, extensive small bowel disease or nodal disease involving the root of the mesentery are contraindications to complete cytoreduction. Complete cytore­duction typically requires an omentectomy, selective peritonectomy, and visceral resection.
For HIPEC, most units prefer a closed technique, which overall reduces exposure of the operative room team and decreases heat dissipation. Other institutions utilize an open technique for delivery. Mitomycin C, oxaliplatin, or doxorubicin is typically used. Selection of the type of chemotherapy agent is typically based on tumor histol­ogy and institutional protocol. Several studies have shown no differ­ence in progression-free survival comparing HIPEC with mitomycin C versus oxaliplatin, the two most used chemotherapy agents. These studies also suggest differences in side-effect profiles, suggesting that more studies are needed.
The inflow and outflow cannulas as well as a temperature probe are placed into the abdomen, and the incision is temporary closed. Using a hyperthermia perfusion pump, 3 to 6 L of warm fluid is instilled until abdominal distension based on intraoperative deter­mination of peritoneal volume. The fluid is heated to about 40° to 43°C. Once the target temperature is achieved, the chemotherapy agent is infused over 30 to 120 minutes. Once this is complete, the abdomen is opened and reinspected. There is no known difference in outcomes based on anastomosis pre- or post-HIPEC. The fascia is closed, and a completeness cytoreduction score is assigned at the end of the case. In early postoperative intraperitonealchemotherapy (EPIC), the abdomen is filled with 1 L of lactated Ringer solution, then mitomycin +/– cisplatin is given continuously or on postopera­tive day 1 and 2 at varying doses. In NIPs + HIPEC + CRS, patients are given intravenous chemotherapy preoperatively and adminis­tered docetaxel and/or cisplatin intraperitoneally on day 1 and day
8. This is repeated three times, and laparotomy with cytoreduction is performed 2 weeks after the last administration of intravenous che­motherapy. These alternatives have shown some promising results in select populations.
Postoperative Management
Depending on institutional support (e.g., nursing levels, telem­etry) patients are admitted to the floor, step-down unit, or ICU. Patients with larger cytoreductions or significant comorbidities benefit from ICU management. Patients are generally at risk of postoperative ileus. Commonly, a nasogastric tube is placed at the time of surgery. Early ambulation and incentive spirometry are strongly encouraged. If extensive diaphragm stripping or resection is performed, some patients with respiratory comorbidities may benefit from chest tubes. Patients are typically managed with fluid restriction after the initial resuscitative phase, which typically is in the first 72 hours. Early discontinuation of intravenous fluids when
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tolerating a regular diet and/or adequately resuscitated is encour­aged. Though ERAS protocols for HIPEC + CRS have not been widely adopted, they do show some promising results in reducing length of stay for patients undergoing HIPEC + CRS, though no RCT has been conducted to date. In general, patients remain in the hospital until they have adequate return of bowel function and pain control. Initially some patients may have electrolyte and met­abolic derangement caused by fluid shifts and should be monitored closely. Risk factors associated with increased risk of complications include number of anastomosis performed, diaphragm resection, number of blood transfusions required, and thermal bowel injuries. Overall postcomplication rates are described between 10% and 40%, depending on the series. Average length of stay is approx­imately 7 to 10 days. Advanced age, malnutrition, and multiple visceral resections are associated with an increased length of stay, hence early intervention to identify patients at most risk is crucial to obtaining quality long-term outcomes for HIPEC and CRS.
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Management ofLower Gastrointestinal Bleeding
Anna Liveris, MD, and Peter Muscarella II, MD
INTRODUCTION
Lower gastrointestinal bleeding (LGIB) is a frequently encountered and complex clinical problem for surgeons. Classically defined as gastrointestinal (GI) bleeding emanating from any point distal to the ligament of Treitz, LGIB can originate anywhere from the small bowel to the anus and accounts for an estimated 30% of all GI bleed­ing. Nearly all LGIB can be isolated to the colon and rectum, with diverticular bleeding being the most common cause. Less than 10% of LGIB originates from the small bowel or anus. Aggressive resusci­tation, accurate localization, and control of bleeding are the primary goals of treatment for patients who present with hemorrhagic shock. A systematic approach to diagnosis and management is pivotal in reducing morbidity and mortality.
Etiology
LGIB can be further categorized as massive, moderate, or occult. Massive bleeds are the most life-threatening, with mortality rates approaching 20%. Despite this, more than 80% of all LGIB will resolve spontaneously, and the overall mortality rate is about 4%. Patients presenting with massive LGIB are usually >65 years and present with hematochezia or bright red blood per rectum in the setting of hemodynamic instability. The most common causes are diverticulosis and angiodysplasia. Interestingly, one-third of patients with presumed massive LGIB will have an upper GI source, so assess­ing for risk factors of peptic ulcer disease is important.
Moderate and occult bleeding can occur at any age. Moderate LGIB presents as hematochezia or melena in a hemodynamically sta­ble patient. The differential diagnosis is broad (Table 1). Occult LGIB is otherwise asymptomatic, except for microcytic anemia resulting from chronic blood loss. The differential diagnosis of these patients includes malignancy, inflammatory conditions, ischemia, and con­genital causes such as bleeding Meckel’s diverticula.
Epidemiology
Approximately 30% of all patients presenting with major GI bleeding are found to have bleeding distal to the ligament of Treitz. Among patients with presumed LGIB, 80% originate distal to the ileocecal valve, with only 10% originating from the small bowel. The remain­ing cases usually arise in the upper GI tract. The overall incidence of LGIB is notably higher in older adult patients, particularly those who are on multiple medications.
Diverticulosis accounts for over 40% cases of LGIB and often presents as painless hematochezia. Diverticular bleeding frequently recurs, and the prevalence increases in patients older than 80 years of age or in those with chronic constipation. Ischemic colitis accounts for 20% of LGIB and is also more prevalent in the elderly. This may occur in response to reduced mesenteric flow to the colon caused by decreased cardiac output, vasospasm, or atherosclerotic disease. Treatment is generally supportive and conservative unless there is evidence of full-thickness necrosis and/or peritonitis. The watershed area of the splenic flexure is a common location for ischemic colitis, and involvement of this area on imaging should alert the clinician to the possibility of this diagnosis. The most common cause of LGIB in patients younger than 50 years of age is benign anorectal disease,
TABLE 1 Differential Diagnosis of Lower
Gastrointestinal Bleeding
Anatomic Source of Bleeding Etiologies
Small intestine Angiodysplasia
Crohn’s disease Mesenteric ischemia Recent surgery/trauma Meckel’s diverticulum Dieulafoy’s lesion Aortoenteric fistula Intussusception
Colon Diverticulosis
Neoplasm Angiodysplasia Inflammatory bowel disease Recent colorectal surgery/trauma Recent colonoscopy/
polypectomy Ischemic colitis Infectious colitis Enterohemorrhagic
Escherichia coli (EHEC)
Salmonella
Campylobacter
Shigella
Cytomegalovirus
Entamoeba histolytica
Fecal impaction Aortoenteric fistula
Rectum Radiation proctitis
Neoplasm Angiodysplasia Rectal varices Fecal impaction Inflammatory bowel disease Solitary rectal ulcer Rectal prolapse Recent colorectal surgery/trauma
Anus Hemorrhoids
Anal fissure Inflammatory bowel disease Local trauma Perianal variceal disease
usually hemorrhoids or anal fissures. The possibility of inflammatory bowel disease (IBD) or NSAID-induced mucosal ulceration should also be considered in these patients. Post-polypectomy bleeding can result in brisk bleeding following colonoscopy and polypectomy. Risk factors include age greater than 65 years and polyp size larger than 1 cm. Though the bleeding is usually self-limited, presentation can be delayed for up to 1 week after the procedure; therefore ascer­taining the history of colonoscopy with polypectomy is crucial.
History and Physical Examination
The differential diagnosis for LGIB is broad, so a thorough his­tory and physical examination is necessary. The history may sug­gest a cause of LGIB and can inform decision-making regarding
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diagnostic evaluation and management. Key details in the history should include the quantity, quality, and frequency of the bleeding, specifically whether the bleeding is recurrent or sporadic. Inquiry into other associated symptoms such as presence of abdominal pain, nausea, vomiting, or a recent change in bowel habits is also war­ranted. The clinician should specifically inquire about prior episodes of LGIB, history of abdominopelvic radiation, trauma, symptomatic arrhythmias, liver disease or cirrhosis, HIV status, and recent endo­scopic or surgical procedures. A detailed review of the patient’s med­ications including antiplatelet agents, anticoagulants, and NSAIDs as well as a family history of colon cancer or inflammatory bowel disease should also be noted.
Abdominal examination and digital rectal examination should be completed in all patients presenting with LGIB. Abdominal exam­ination may reveal tenderness, distension, or a mass. Digital rectal examination is important to inspect for anorectal pathology such as hemorrhoids or fissures. Additionally, the quality of the stool in the rectal vault, whether it is impacted, dark melena, maroon-colored, or frank blood, should be documented. Importantly, the clinician should pay close attention to the patient’s vital signs at all points during the history and physical examination as any hemodynamic instability war­rants a rapid resuscitation and aggressive diagnostic effort.
MANAGEMENT
All patients presenting with LGIBshould be triaged and evaluated immediately as decompensation can be rapid. Administration of supplemental oxygen, the establishment of intravenous lines access with two large-bore peripheral venous catheters, and placement on a cardiopulmonary monitor should be performed initially. Infusion of crystalloid solutions should be started immediately to resuscitate the patient. Laboratory examination should include a complete blood count, metabolic panel, liver function tests, lactate, coagulation stud­ies, and a type and screen.
important to minimize mortality. Aggressive efforts to correct coag­ulopathy and metabolic derangements before surgical intervention should be undertaken, although salvage procedures may be required in rare cases. This will be discussed further in later sections.
Special Hematologic Considerations
Early identification of hematologic disorders or medications is man­datory during the resuscitative process. Laboratory studies, including traditional coagulation studies and possibly TEG, should be obtained during the initial workup. Anticoagulants and antiplatelet agents should be discontinued, and reversal should be considered in patients with hemodynamic instability or ongoing bleeding. For patients who are therapeutic or supratherapeutic on warfarin, a prothrombin con­centrate complex should be considered. Vitamin K and fresh-frozen plasma can also be utilized for this purpose, but prothrombin complex concentrate has the advantage of rapid reversal with lower fluid vol­umes. In recent years, idarucizumab has become more readily available to reverse dabigatran. Although not widely available yet, andexanet alfa has also been approved by the US Food and Drug Administration (FDA) for the reversal of apixaban and rivaroxaban. Currently, there is no specific reversal agent for antiplatelet agents such as aspirin and clopidogrel. Most clinicians favor early platelet transfusion and/or desmopressin administration in the setting of active hemorrhage. Car­diology consultation should be considered for patients who have had drug-eluting cardiac stents placed within the past year because they are at risk for stent thrombosis if dual antiplatelet agents are discontinued, and this can contribute to mortality. It may be reasonable to continue aspirin therapy in some of these patients. Desmopressin administra­tion can be particularly useful to reverse coagulopathy in the uremic patient. For patients with inherited or acquired coagulation disorders, specific reversal agents and therapies should be guided in consultation with the hematology service. More specialized laboratory studies may be indicated in some patients.
Resuscitation and Transfusion
Appropriate resuscitation of a patient with LGIB is crucial to minimize morbidity. The process should begin as described earlier as soon as it is recognized that the patient is actively bleeding. For patients with evidence of multiple comorbidities or massive LGIB, a critical care consultation and monitoring in a critical care setting is warranted.
Most patients with moderate or occult LGIB present without signs of instability. These patients may warrant less aggressive resus­citation with crystalloid during their initial workup and evaluation. Transfusion should be initiated to correct any overt coagulopathy and to maintain a hemoglobin >7 g/dL for most patients. Some patients, particularly those with other comorbidities, may require a higher goal hemoglobin and should be treated on an individual basis. International normalized ratio (INR) should be corrected to <1.5, and platelets should be transfused to >50,000/L.
The massive LGIB patient who presents in hemorrhagic shock is similar to a trauma patient. Therefore, activation of a massive transfusion protocol and the use of empiric blood product ratios of 1:1:1 of packed red blood cells to fresh-frozen plasma to platelets in order to correct coagulopathy is effective. Early use of fresh-frozen plasma and platelets should be considered. The end goals of resus­citation are correction of coagulopathy and hemodynamic support. A policy of permissive hypotension with systolic blood pressure >90 mm Hg is sufficient for most patients. Although crystalloid solutions may be indicated in other cases of LGIB, care should be taken to avoid the overuse of crystalloids in this subset of patients because this may contribute to bowel edema and other complications such as abdominal compartment syndrome or respiratory failure. The use of thromboelastography (TEG) may also be a useful adjunct for the care of the hemodynamically unstable LGIB patient in centers where this technology is available. Prompt progression to the next phases of management, bleeding localization and hemorrhagic control, is
Localization
The first step in management and hemorrhage control is localiza­tion of the bleeding site. As previously discussed, LGIB has a broad differential, and identifying the source of bleeding is tantamount to further management.
Nasogastric Lavage
An upper GI source should always be considered in patients with suspected LGIB, particularly in patients with hemodynamic instabil­ity, brisk bleeding, or unrevealing evaluation of the lower GI tract. Bleeding peptic ulcers, angiodysplasia, or esophageal varices can often manifest as visible blood in the stool. Clearly, management diverges drastically if the source of bleeding is in the upper GI tract. Nasogastric lavage has classically been recommended as the first step in deter­mining an upper versus lower GI source, particularly in the unstable patient. A nasogastric tube is inserted bedside, and then the contents of the stomach are suctioned. Alternatively, 200 to 300 mL saline is instilled into the tube and then suctioned back to look for blood or cof­fee grounds in the stomach. Fluid with bile present but without blood is considered to be a negative lavage. The lack of bilious fluid suggests inadequate evaluation of the post-pyloric region. A clear effluent is considered nondiagnostic and is not uncommon. Disadvantages of nasogastric lavage include patient discomfort and lack of therapeutic benefit. Nasogastric lavage has fallen out of favor in recent years and should be reserved for cases of suspected upper GI hemorrhage to improve visualization at the time of endoscopy. The authors liberally employ the use of upper endoscopy for the evaluation and manage­ment of GI bleeding because of its numerous advantages.
Anoscopy/Rigid Sigmoidoscopy
In patients with a strong suspicion for GI bleeding from the ano­rectum or distal sigmoid, anoscopy or rigid sigmoidoscopy should
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be considered. Anoscopy can be quickly performed with little to no sedation at the bedside by inserting a tubular instrument into the patient’s anus to visualize hemorrhoids, anal fissures, fecal impac­tion, or local trauma to the anus. Anoscopy can also be therapeutic as it can be used to assist with banding or other treatment of bleed­ing hemorrhoids. Rigid sigmoidoscopy is also a technically simple bedside procedure but generally requires additional sedation. The instrument is longer and allows for insufflation, which can facilitate visualization of the rectal and distal sigmoid mucosa. Both pro­cedures can be uncomfortable for the patient and provide limited visualization of the most distal GI tract. When possible, flexible sigmoidoscopy or colonoscopy is preferred.
Colonoscopy
When there is a high degree of suspicion for a colorectal source of LGIB, colonoscopy is the modality of choice to localize the source if possible. It has been shown to correctly identify the location of LGIBin more than 75% of patients. Colonoscopy is performed using a flexible scope guided from the anus through the entirety of the rec­tum and colon until the ileocecal valve is reached. Colonoscopy can detect discrete sources of bleeding, such diverticula, angiodysplasia, and tumors, as well as more diffuse sources of bleeding, such as inflammatory bowel disease, ischemic colitis, and radiation proctitis.
An important benefit of the procedure is the ability to perform therapeutic intervention. Bleeding should only be ascribed to lesions with stigmata of recent hemorrhage, including visualized bleeding, exposed blood vessels, or adherent clots. Colonoscopic hemostasis can be achieved with dilute epinephrine injections (1:10,000) in 1 to 2 mL aliquots up to 30 mL total. This result is usually temporary, and a sec­ond hemostatic method is recommended. Epinephrine injections are best suited to facilitate site identification in cases of active or copious bleeding. Endoclip placement results in hemostasis for nearly all diver­ticular bleeds with stigmata of recent hemorrhage and in nearly 70% with other forms of LGIB (Fig. 1). Other endoscopic techniques for hemostasis include bipolar electrocoagulation, heater probe cautery, argon plasma coagulation, and rubber band ligation. Angiodysplasia is particularly amenable to argon plasma coagulation (Fig. 2). Rubber band ligation has the highest rates of rebleeding and can add signifi­cant procedure time depending on the site. Tattooing is recommended to expedite site identification in the event of recurrent bleeding, partic­ularly if surgical intervention is determined to be necessary.
The timing of colonoscopy in the evaluation of LGIB remains controversial. Ideally, a bowel prep should be attempted to maxi­mize visualization during the procedure. Notably, early colonoscopy performed while the patient is actively bleeding has been shown to improve diagnostic yield. Colonoscopic evaluation following bowel
FIG. 1 (A) Colonic diverticulum with stigmata of recent hemorrhage. (B) Successful endoscopic clipping of bleeding diverticulum. (Courtesy Daniel S. Behin,
MD, Montefiore Medical Center/Albert Einstein College of Medicine, New York.)
FIG. 2 Cecal angiodysplasia before (A) and after (B) endoscopic argon beam plasma coagulation. (Courtesy Daniel S. Behin, MD, Montefiore Medical Center/
Albert Einstein College of Medicine, New York.)