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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_1369_Библиотеки_им_академика_М_И_Перельмана.pdf
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E.P. Davila and C.H. Otero
Robotic surgery was approved for clinical use by the FDA in 2000 and has been
applied to several surgical procedures in urology, cardiac surgery, and gynecology.
Although robotic-assisted procedures for general surgery are becoming more frequent,
it continues to raise concerns about its higher cost compared with laparoscopy.
Preoperative Assessment
Appropriate risk reduction strategies could take the form of a guideline or checklist of
key points to be considered at each stage of the patient’s journey (e.g., surgical outpatients, cardiovascular preoperative evaluation, anesthetic pre-assessment, inpatient
admission, operating room, recovery area and discharge suite). The ideal scenario for the
surgical treatment of the obese is having on the schedule a checklist with the participation of clinical specialists who can lead the patient to a safe surgery. The case selection,
counseling, or referral for counseling should be done considering the patient’s conditions, such as smoking cessation, preoperative dietary advice, thromboprophylaxis, and
planning for postoperative care and discharge. Each hospital should have its own policy
or protocol for the management of the morbidly obese patient. Each patient should be
individually assessed for risk and the care and treatment should be consultant-led [5].
It has been thought that obese patients are associated with poor surgical
outcomes and that they are more likely to exhibit comorbid medical conditions,
particularly cardiovascular, metabolic, and respiratory diseases conferring an
increased morbidity and early mortality rate compared to the general population.
Diabetes: The impact of diabetes in the surgical patient is significant. It has been
identified as an independent risk factor for postoperative morbidity. Diabetic
patients can spend up to 50 % more time in the hospital postoperatively compared
with nondiabetic patients [6].
For the preoperative patient, the HbA1c is a more useful test as it evaluates the
degree of hyperglycemia that red blood cells have been exposed to over the 120-day
life span of the cell.
A study of 7310 patients (Lauruschkat et al.) for coronary artery bypass surgery
found that patients with undiagnosed diabetes more frequently required resuscitation and re-intubation and that have had a higher perioperative mortality compared
with nondiabetic patients and known diabetics [7].
Most diabetic oral medications can be taken up until the day before surgery and
are held on the day of surgery when patients are fasting. Patients taking any oral
medication for diabetes should have their blood glucose monitored both immediately before and after their surgery. If patients develop hyperglycemia when off their
oral agents, supplemental insulin should be used to correct the elevated blood glucose. Most insulin-dependent diabetics rely on both short-acting and long-acting
insulin to control their blood glucose levels.
Diabetic patients should be operated on as early in the morning as possible.
The patient may present a metabolic decompensation state to remain fasting long
time, creating a state of ketosis and oxidative stress. Also catecholamine and other
10 Surgery on Obese Patients
117
counter regulatory hormones release and increase cytokines. The stress of surgery
is an issue with glycemic control [8]. Systemic reaction to trauma seen in the surgery can worsen even more his metabolic decompensation; with surgery one additional risk factor is added.
Cardiovascular: The challenges for the clinician before surgery are to identify if the
patient has an increased preoperative cardiovascular risk, carefully perform supplemental preoperative evaluations, and manage the preoperative risk. Three pathologies related to cardiovascular disease are present in obese patients: arterial
hypertension, arrhythmias, and thromboembolic disease. The association between
hypertension and obesity has been well established by several studies. The risk of
developing hypertension is greater in younger individuals and increases with obesity. It decreases with weight loss likely due to a reduction in sympathetic nervous
system activity and suppression of the renin–angiotensin system. Particularly in
women, the risk of an adverse perioperative cardiac event is related to the degree of
underlying cardiac heart disease, associated comorbidities, and the type of surgery
undergone. Walsh et al. [9] investigated the incidence and clinical correlates of postoperative cardiac arrhythmias in patients undergoing elective large bowel resection
and acute postoperative hypertension, which is one of the more devastating cardiovascular complications after surgery. The cardiologist who evaluates obese patients
for cardiovascular disease and preoperative consultation should consider sleepdisordered breathing in obese patients who present polycythemia and who are habitual snorers or have nocturnal gasping and choking and have been witnessed having
episodes of apnea and daytime sleepiness. The estimated data from the National
Health and Nutrition Examination Survey III (NHANES III) points that white
2
Caucasian 20–30 years of age with a BMI ≥45 kg/m
will lose 8 years of life and
their male counterparts will lose 13 years [10].
Obtaining a thorough medical history and physical examination is mandatory to
coordinate an operative plan. Specifically, comorbidities such as diabetes, obesity,
smoking, and collagen vascular disease may critically affect the operative plan.
Pulmonary embolism is the leading cause of mortality in experienced bariatric
surgery centers. Obesity is an independent risk factor for postoperative development
of deep vein thrombosis (DVT). DVT is caused by decreased circulating antithrombin III and decreased fibrinolytic activity. The surgical team must identify patients
who are at high risk of developing DVT.
DVT prophylaxis should be initiated before the induction of anesthesia. Low
molecular weight heparin such as enoxaparin has been used for thromboembolism
prophylaxis, and nowadays it is considered the gold standard in DVT prevention.
Sequential compression devices applied during and after surgery for DVT prophylaxis become the auxiliary device to prevent clot formation in the legs.
The indications for further testing for perioperative cardiovascular morbidity in
the general population according to the “revised cardiac risk index” include (1)
emergency surgical procedures and major thoracic, abdominal, or vascular surgery,
(2) past or present history of coronary heart disease, (3) history of congestive heart
failure, (4) cerebrovascular disease, (5) diabetes, and (6) preoperative serum creatinine levels >2.0 mg/dL [11].
118
E.P. Davila and C.H. Otero
Pulmonary System: Hypoventilation and obstructive apnea were observed in patients
with severe obesity. In very obese patients, symptoms are habitually nonspecific.
Sleep apnea is the most important respiratory problem, with several studies confirming that obesity is a major risk factor for the development of this condition.
Oxygen consumption and carbon dioxide production are more marked in obese
patients. Excess body weight around the ribs and under the diaphragm and intraabdominal organs reduce chest wall compliance. The difficulty to expand the chest
and the increased oxygen demand causes significant pulmonary deficit characterized by alterations in the pulmonary volumes. There is a reduction in functional
vital capacity, total lung volume, total capacity, and expiratory reserve volume,
which is a typical rank of a restrictive pattern. They develop more atelectasis, which
persists and even tends to increase after anesthesia. As a result of atelectasis, most
patients will exhibit low arterial oxygen pressures after open gastric bypass surgery.
Vital capacity and maximum voluntary ventilation is reduced. Obesity leads a series
of respiratory changes affecting the volumes, compliance, and ventilation/perfusion
ratio, causing in turn a permanent hypoxemia. This results in a substantial alteration
in the functional respiratory capacity and total lung capacity. The expiratory reserve
volume is also compromised by 35–60 % due to the obese abdomen shifting the
diaphragm into the chest. Obese patients have increased inflammatory factors, elevated plasma fatty acid, and decreased antithrombin III, generating an important
prothrombotic state leading to a predisposition for thromboembolic disease. The
use of laparoscopic techniques has decreased the amount of postoperative pain the
patients’ experience, and as a result, respiratory complications are decreased.
Technical Considerations
Obesity has long been suggested as a risk factor for conversion to open surgery during laparoscopic colorectal resection. In obese patients, peritoneal cavity access
may be more difficult, and there is suboptimal peritoneal distention, reducing vision
and operating capacity for the surgeon (Fig. 10.1).
Obesity is associated with increased conversion rate, operating time, and postoperative morbidity of laparoscopic colorectal surgery but does not affect surgical safety
or oncological security. Some authors expect that with the application of laparoscopic
surgery in patients with cancer, the oncological results have improved outcomes.
Balentine et al. [12] found fewer complications and rapid recovery in minimally invasive surgery than the open surgery in cancer patients and also more accurately lymph
node resection and more technically demanding due to hindered exposure of the
bowel, thickened mesentery with difficulty in dissection, mobilization, or ligation of
the vessels. The total mesorectal excision (TME), now the standard technique for
surgical treatment of rectal cancer, has led to a reduction in local recurrence rates. The
relative inaccessibility of the rectum within the bony pelvis and the proximity of other
major anatomic structures place particular technical challenges to surgeons. High
BMI increases the technical difficulty of TME and can compromise the possibility of
complete resection, resulting in poorer oncologic outcomes [13] (Fig. 10.2).
10 Surgery on Obese Patients
Fig. 10.1 Morbidly obese patient
119
Fig. 10.2 Relative inaccessibility within the bony pelvis
The da Vinci robot (Intuitive Surgical, Sunnyvale, CA, USA®) offers numerous
advantages when compared to laparoscopy, including several degrees of motion,
three-dimensional (3D) imaging, and superior ergonomics that enable easy and precise intracorporeal suturing. The improved visualization and tremor-less precision
form the basis for the emergence of robotic techniques (Fig. 10.3).
120
Fig. 10.3 Robotic docking
E.P. Davila and C.H. Otero
Fig. 10.4 Patient with proper padding
Positioning: Positioning is a challenge in obese patients; they are at higher risk
for pressure sores and neural injuries depending on the position used for surgery.
Placement is always necessary in these patients by limitation of intra-abdominal
space needing a table that can accommodate the specific weight of the patient with
proper padding, beanbag, and appropriate retrains over the chest and also sometimes adequate arm boards (Figs. 10.4 and 10.5).
Gaining Intraperitoneal Access: Gaining safe intra-abdominal access remains
the first step in minimally invasive surgery. This can be made difficult in the morbidly obese and in multiply operated abdomen. Sites of previous operative intervention will certainly influence the strategy to gain initial access. Individual surgeons
will need to judge their laparoscopic capabilities realistically in offering laparoscopic colorectal procedures to their morbidly obese patients.
10 Surgery on Obese Patients
Fig. 10.5 Bean bag and retrains
121
Fig. 10.6 Trocar with direct laparoscopic visualization
With proper preparation and careful consideration of surgical pitfalls of laparoscopy and robotics, the majority of the colorectal procedures that can be performed using a Veress needle or a trocar with direct laparoscopic visualization
(Fig. 10.6) may be an easier approach, but traditional landmarks cannot be used
in the morbidly obese patients. For extremely obese patients, longer trocars may
be used, although these are rarely needed; for the robotic camera arm, the trocar
should be 15 cm in length (Fig. 10.7). In these morbidly obese patients, the
umbilicus is pulled downward. This means that some trocars need to be placed in
the supraumbilical area. Leroy et al. analyzed 123 patients with laparoscopic left
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Fig. 10.7 Large trocars
E.P. Davila and C.H. Otero
Fig. 10.8 Umbilicus pulled downward
colectomy and reported that an increased number of ports were required in obese
patients compared to non- obese patients.
Trocar Selection and Port Placement: Traditional landmarks cannot be used in
the obese patient. For extremely obese patients, longer trocars may be used, although
these are rarely needed. For the robotic camera arm, the trocar should be 15 cm in
length. In these obese patients, the umbilicus is pulled downward. This means that
some trocars are placed in the supraumbilical area (Fig. 10.8).
10 Surgery on Obese Patients
Fig. 10.9 In obese trocar position to reach the target
123
Incisions are placed 20–25 cm from the target, but in the obese, the distance
should be confirmed and measured once the camera is inside the abdomen. Once
the first port is placed under pneumoperitoneum, a minimum of 8–10 cm is measured between all trocars. Sometimes “cheating” on the trocar is necessary to be
able to reach the target with minimal loss of the function of the robotic arm
(Fig. 10.9).
If the patient is morbidly obese, the trocars are usually placed closer to the target anatomy. One example is the right colectomy where the ports tend to be closer
to the umbilicus and midline in these obese patients, compared to their counterparts that are placed more laterally. This is because it is easier to go over the
colonic flexures and able to see laterally straight down to the line of Toldt with the
30° down scopes.
In 1974 Palmer [14] described a technique of putting a small trocar below the left
costal margin for an abdominal entry. This author prefers to use this technique
because in the subcostal region in the mid-clavicular line, the abdominal wall is
thinner by the ribs exerting traction (Fig. 10.6), but the surgeon should do the technique that he or she is comfortable with.
There is much controversy over the number of trocars and where to place them.
But the most important thing is to place the necessary trocars to improve the
performance.
Important steps to identification of anatomy will be:
1. Traction, countertraction, and triangulation are the key for success (Fig. 10.10).
2. If mesentery is short, may start laterally gaining length on the mesentery elevation and then go medial for vessel control.
3. Make windows in the mesentery for vessel control enabling to use clips or
staples on vessels.
124
Fig. 10.10 Traction
countertraction and
triangulation
E.P. Davila and C.H. Otero
4. May use ureteral illuminated stents for pelvic procedures. This will speed
your procedure and also add safety against ureteral injuries. This is not the
same as using illuminating stents.
5. If the patient has a colorectal lesion, it should be marked with tattoo in four
quadrants to be able to identify easier the lesion, even when marked mesentery and omentum.
6. Mobilize the omentum to expose the colon and move the table to be able to
gain exposure.
7. Rectal traction is performed cephalad by the assistant by using an umbilical tape placed around the bowel making this traction more effective and
minimizing tearing the bowel specially when the colon is very heavy from
the obesity.
8. Don’t hesitate to place another assistant port if needed for suctioning while
you traction with the other port or to improve the exposure.
9. In very difficult procedures if exposure is not adequate before conversion
may use hand-assisted device to prevent a laparotomy if possible.
10. May use high flow insufflators or even sometimes two insufflators at the
same time in super-morbid obese patients.
11. Narrow pelvis is frequently seen in males and if obesity is added, this
becomes a challenge even for the expert surgeons. The robotic techniques
allow a more control access due to the four arm exposure in the pelvis.
12. In robotic colorectal procedures exposed is performed by opposite traction
of two arms and dissection for the third arm while placing the camera to be
able to see the target anatomy and tall of them.
10 Surgery on Obese Patients
125
Postoperative Management
Complications are more common in the obese patient. Infections are increased almost
twofold, and the odds of developing sepsis are significantly increased by 90 % [15].
To reduce these risks, it will be important to understand and remedy specific problems associated with obesity itself, both in the hospital and after discharge.
Obese patients should be treated in the postoperative period accurately and with
the utilization of a checklist to avoid adverse outcomes.
The most common complications are infection of the surgical site and respiratory
complications. Surgeons must take special care of obstructive sleep apnea. The use
of positive pressure equipment is necessary to provide optimum levels of oxygen
and thoracic expandability.
Surgical Site Infection (SSI): The reported prevalence of SSI is highly variable
because of differences in SSI definitions, detection, and reporting. The reported
incidence of SSI among colon and rectal procedures typically ranges from 25 to
45 %, depending partly on the respective institution’s experience.
Procedures for diverticular disease, inflammatory bowel disease, and ostomy
reversal incur the highest rates of SSI; gradually obesity is being identified as a risk
factor for wound infection following colon and rectal surgery.
Khoury et al. [4] defined the impact of obesity on laparoscopic intestinal resection,
including both colorectal and small bowel resection, with a case-matched study
between obese and non-obese patients. Obese patients defined by a BMI >30 kg/m
experienced a significantly greater occurrence of wound infection (10.6 % vs. 4.8 %)
even though intra-abdominal abscesses occurred with similar frequency [16]. In this
same author (Khoury et al. in 2010), the morbidly obese patients had higher rates of
wound infection, anastomotic leak, and abdominal abscess, as well as higher readmission and reoperation rates. In the last years, the literature has demonstrated a
significantly lower tissue concentration of perioperative antibiotics in obese patients
despite a twofold higher dose in comparison to normal-weight patients. Adipose tissue concentration of preoperative antibiotics remained below the minimum inhibitory concentration and was suggested as a potential mechanism for increased SSI
among obese patients [17]. A large cohort study included 8415 colorectal operations
of which 5291 (62.9 %) had a minimally invasive surgical approach. Overall, 25.6 %
had no bowel preparation, 44.9 % had mechanical bowel preparation only, and 29.5 %
received oral antibiotic bowel preparation. The SSI rate was 11.1 %, and it varied by
preparation type: 14.9 % no preparation, 12.0 % in mechanical bowel preparation,
and 6.5 % in oral antibiotic (P < 0.001). Oral antibiotic bowel preparation group had
significantly shorter hospital LOS: (median, 4; interquartile range, 3–6) versus other
preparations (median LOS, 5) (P < 0.001) [18].
2
Pulmonary System: Respiratory difficulties due to pressure on the diaphragm or due
to an increase of intra-abdominal pressure predispose the presence of atelectasis,
which is more frequent in the less mobile patient.
Pain management in these patients is a key point in the improvement. Breathing
exercises and respiratory therapy help prevent respiratory complications such as