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284
ab
E. G. Weiss and L. Force
mous epithelial lining. Dermoid cysts are further differentiated, and contain dermal
appendages such as hair and sweat glands.
These lesions may present with a draining
sinus or dimple in the post-anal area, which
may be confused for an abscess. Tailgut cysts
contain columnar epithelium, and may secrete
mucus. Rectal duplication cysts are another
type of congenital lesion. These cysts contain
all cell types and structures of a normal piece
of intestine. Teratomas contain cells that can
differentiate into any cell type. These have a
higher rate of malignant degeneration, 5–10%,
when compared to other developmental cysts.
When they degenerate, they may become
adherent to the coccyx, rectum or other
viscera.
Chordomas are the most common malignant presacral tumors (Fig.36.3). They arise
from the fetal notochord, 1/3 of the time they
are located in the retrorectal space, however,
they may arise anywhere along the spinal
column. Chordomas are slow growing
tumors, the majority will be detected at age
40–60 with a male predilection. As chordo-
mas grow, they tend to invade surrounding
structures which cause worsening pain,
incontinence and neurogenic complaints.
Since these tumors are locally aggressive,
recurrence is noted in up to 44% of patients
after resection. A radical resection of all
affected tissue is indicated, which would
include wide margins and resection of any
involved structures en-bloc.
Anterior sacral meningocele occurs
when the dural sac herniates through a
defect in the sacrum (Fig. 36.4). The sac
communicates with the subdural space and
contains CSF. More commonly found in
women, these may present with patients
complaining of a headache during defecation. They may also present as life threatening meningitis. A sacral meningocele may
be diagnosed by plain radiograph by the
presence of a Scimitar sign, again characterized by the rounded appearance to the
sacrum. It is very important that the dura be
repaired during resection of these tumors.
Failure to do so will result in CSF leak or
infection of the dural space.
Fig. 36.3 (a) Sagittal view of a sacral chordoma. (b) Sagittal view of large sacral chordoma. (Couresy of Dr. Laurence
Sands)
ab
36 Retrorectal Tumors
Fig. 36.4 (a) Axial and (b) sagittal view of an anterior meningocele. (Courtesy of Dr. Laurence Sands)
285
G. Neurogenic
Neurogenic lesions include neurobromas,
neurolemmomas, ependymomas, ganglioneuromas, and neurobrosarcomas (Fig. 36.5).
These lesions account for approximately 10%
of all retrorectal tumors. These may be benign
or malignant, however, their behavior is difcult to preoperatively determine. The majority
of these patients will present with neurologic
complaints as a presenting symptom.
H. Osseous
Osseous lesions can be either benign or
malignant and include osteoma, osteogenic
sarcoma, sacral bone cysts, Ewing tumors,
giant cell tumors or chondromyxosarcomas
(Fig.36.6). Osseous tumors tend to be locally
aggressive and have metastatic potential.
Resection of these lesions is indicated with a
radial excision of all involved structures, usually done in conjunction with an orthopedic
surgeon. Aggressive tumors such as Ewing or
osteogenic sarcoma may benet from neoad-
Fig. 36.5 Neurogenic retrorectal tumor
juvant radiation and chemotherapy.
286
ab
Fig. 36.6 Two views of an invasive chondrosarcoma
E. G. Weiss and L. Force
I. Miscellaneous
This diverse group of pathologic diagnoses
may include any inammatory masses from
chronic infection or anastomotic leak from
the rectum as well as metastatic disease, lymphomas, lymphangiomas, desmoid tumors,
leiomyomas, brosarcomas or endotheliomas. These tumors can occur anywhere
within the retroperitoneum. Endometriomas
can also be found in the retrorectal space.
Metastatic disease in this space is most commonly from a rectal cancer primary.
Gastrointestinal stromal tumors (GIST) can
also arise in the presacral space.
The prone/posterior (Kraske) approach is
appropriate for tumors that are below the level
of S4 (Fig.36.7). Any tumor that extends proximally to this landmark may not be surgically
accessible through the posterior approach.
This approach is acceptable for small, benign
tumors. Any tumor that has concern for invasion into surrounding structures, lateral sidewall or neurovascular structures should not be
approached through a posterior approach
alone. Technically this operation is performed
with the patient in prone jack-knife position
with a transverse incision overlying the coccyx
or a vertical incision from the anal verge to the
coccyx. Once the subcutaneous tissue is
entered, the anococcygeal ligament and levator
Treatment
should be incised to gain access to the coccyx
and retrorectal space. Care is taken to avoid
J. Prone/Posterior Approach
Surgical excision of retrorectal tumors is
indicated for any type of tumor. These masses
have a tendency to harbor malignancy or
undergo malignant degeneration. Benign
congenital cysts may become infected and
lead to problems with abscesses and stula
formation, which adds morbidity to any
planned surgical procedure. Excision of these
masses in women of child bearing age is also
particularly important, since these women
may have complications during childbirth
secondary to vaginal obstruction.
any injury to the muscular wall of the rectum,
which may increase postoperative infection
rates. The sacral nerves are also well visualized
in this technique. The tumor is then able to be
exposed and dissected free from the retrorectal
space. A nger within the rectum may help to
identify the wall to prevent injury rectal injury
or to facilitate recognition of such injury. A
drain should be left post operatively, since
there is usually a large space left by the tumor.
K. Combined Abdominal/Posterior
The combined posterior/abdominal approach
is utilized for patients with tumors that
ab
36 Retrorectal Tumors
c d
287
Fig. 36.7 (a) Preoperative marking for a posterior approach (b) intraoperative picture of resection of tumor. (c) Closure
of the wound with drain (d) picture of the resected cyst. (Courtesy of Dr. Eric G.Weiss)
extend above S3, usually with concern for
invasion into the sacrum or involvement of
other pelvic structures such as iliac vessels,
ureters, sacral nerve roots or rectum. This
approach is useful to be able to correctly
identify and control structures prior to resection of the tumor. Vascular control is imperative if the tumor is invasive into the vascular
structures. Ureteric stents may be utilized to
identify the ureters. The tumor can be
approached from the abdomen and continued
into the perineum, when no more dissection
can be done from above. This approach is
particularly useful for anterior sacral meningocele, where the sac can be dissected from
the perineum and ligated from within the
abdomen. These tumors require a multidisciplinary team of surgeons to resect the tumor
including colorectal, orthopedic, plastic and
neurosurgeons.
The abdominal approach is initiated by
mobilizing the left colon and rectum. The
dissection is similar to a total mesorectal
excision, and the retrorectal space is accessed
from the sacral promontory. Care is taken to
dissect the rectum free from the tumor. If the
tumor is densely adherent to the rectum or
invading into the rectum, a proctectomy
should be performed. In the majority of cases
an anastomosis can be safely performed,
either as a stapled or a hand-sewn anastomosis. However, extensive soft tissue involvement of the perineum may mandate
abdominoperineal resection.
If a malignant tumor invades the sacrum, a
partial sacrectomy should be performed.
Preoperative determination of the level of
resection is important. The abdominal dissection is important to identify any nerves, ureter
and vessels to protect them during resection.
288
E. G. Weiss and L. Force
Exposure from above and below is important
when performing a partial or hemisacrectomy.
Sacral resections below S3 are tolerated fairly
well in terms of function. Resections above S3,
including S2/1 will be very morbid for the
patient. Sequelae include both fecal and urinary incontinence and dysfunction for patients
with a unilateral resection. Bilateral resection
will guarantee abnormal function. There is also
considerable bony reconstruction involved to
ensure lumbar-sacral stabilization.
Extensive resections may result in large soft
tissue defects, for which ap closure may be
required. For smaller defects, a V-Y ap or
gracilis ap may be used to ll soft tissue
defects. For large defects, a transversus abdominis myocutaneous ap may be required.
L. Abdominal
The abdominal approach is appropriate for
tumors that lie above S3. The characteristics
of the tumor, including invasion into the surrounding structures should be evaluated with
preoperative imaging. This approach is appropriate for tumors that do not extent into the
sacrum, which would be better served with a
combined approach. Preoperative placement
of ureteric stents may also be benecial to
identify the ureters, if the dissection plane is
not clear during resection. Anterior resections
may be laparoscopically performed.
M. Adjuvant/Neoadjuvant Chemo and Radiation
Treatment of retrorectal tumors is primarily
with surgery. Locally advanced tumors that
are not resectable may be treated with palliative chemotherapy or radiation, however
results are poor. Treatment is based on the
tissue type and characteristics of the tumor.
Chordomas, for instance, are radioresistant.
For large GIST tumors in the retrorectal
space, neoadjuvant imatinib can be considered prior to surgical resection.
Suggested Reading
Glasgow SC, Birnbaum EH, Lowney JK, Fleshman JW,
Kodner IJ, Mutch DG, et al. Retrorectal tumors:
a diagnostic and therapeutic challenge. Dis Colon
Rectum. 2005;48:1581–7.
Hobson KG, Ghaemmaghami V, Roe JP, Goodnight JE,
Khatri VP.Tumors of the retrorectal space. Dis Colon
Rectum. 2005;48:1964–74.
Hosseini-Nik H, Hosseinzadeh K, Bhayana R, Jhaveri
KS. MR imaging of the retrorectal-presacral
tumors: an algorithmic approach. Abdom Imaging.
2015;40:2360–644.
Macafee DAL, Sagar PM, El-Khoury T, Hyland
R. Retrorectal tumors: optimization of surgical approach and outcome. Colorectal Dis.
2012;14:1411–7.
Merchea A, Larson DW, Hubner M, Wenger DE, Rose
PS, Dozois EJ. The value of preoperative biopsy in
the management of solid presacral tumors. Dis Colon
Rectum. 2013;56:756–60.
Messick CA, Hull T, Rosselli G, Kiran RP.Lesions origi-
nating within the retrorectal space: a diverse group
requiring individualized evaluation and surgery. J
Gastrointest Surg. 2013;17:2143–52.
Sagar AJ, Tan WS, Codd R, Fong SS, Sagar PM.Surgical
strategies in the management of recurrent retrorectal
tumors. Tech Coloproctol. 2014a;18:1023–7.
Sagar AJ, Koshy A, Hyland R, Rotimi O, Sagar
PM. Preoperative assessment of retrorectal tumours.
BJS. 2014b;101:573–7.
Toh LWT, Morgan M.Management approach and surgical
strategies for retrorectal tumors: a systematic review.
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Rectal Cancer: Local Therapy
DavidM.Lisle andDanaR.Sands
37
Refer toAlgorithm in Fig.37.1
A. Morphology. The traditional characteristics of
tumors considered to be amenable to local excision include: size less than 3cm, less than 1/3
circumference of the rectal wall, mobile, low
lying and those not situated on the anterior wall.
These stipulations are not necessarily mandated
when considering local excision with transanal
endoscopic techniques. Certainly, xation of
the tumor would suggest locally advanced disease and would be a contraindication. Anterior
lesions should be approached with caution
for the urinary and gynecologic structures
but are not contraindicated for local excision.
Size stipulation and degree of circumferential
involvement are less important considerations
than is proper staging and surgeon experience and skills to manage larger lesions. The
proximal extent of resection has been greatly
extended with transanal endoscopic techniques.
Peritoneal entry is not uncommon and can be
adequately managed in experienced hands.
B. Local excision does not involve removal of
rectal lymph nodes. The goal is, therefore, to
D. M. Lisle
Medstar Franklin Square Medical Center
forDigestive Disease, Baltimore, MD, USA
D. R. Sands (*)
Department ofColorectal Surgery, Cleveland Clinic
Florida, Weston, FL, USA
e-mail: SANDSD@ccf.org
identify those early cancers that are conned to
the bowel wall without lymph node metastasis.
Preoperative staging is vital to decision making
as a high suspicion of lymph node metastasis
preoperatively would make local excision an
inadequate oncologic operation. The radiologic staging of rectal cancer has traditionally
employed endorectal ultrasound for locoregional disease assessment. The depth of invasion had been reported with 65–90% accuracy
while the nodal involvement accuracy ranges
from 60–80%. Rectal MRI has evolved over the
last decade to provide valuable information for
physicians treating patients with rectal cancer.
High resolution MRI is capable of differentiating the degree of rectal wall invasion. Early rectal cancer and degree of submucosal invasion
are still a challenge to accurately diagnose with
any radiographic modality. Nodal involvement
with specic criteria such as heterogeneous signal intensity and irregular capsular borders are
accurate predictors of metastatic spread. Large
vein extramural vascular invasion and mucin
deposits are also assessed with high resolution
MRI and are considered poor prognostic indicators. Depth of invasion of the rectal wall is an
important predictor of lymph node metastasis
(Table 37.1). Therefore, only T1 and some T2
cancers with no suspicious lymph nodes on preoperative MRI or endoscopic ultrasound should
be considered for local excision.
C. Certain histologic features of rectal cancer
are also associated with higher risk of lymph
© Springer Nature Switzerland AG 2020
S. R. Steele etal. (eds.), Clinical Decision Making in Colorectal Surgery,
https://doi.org/10.1007/978-3-319-65942-8_37
289
290
D. M. Lisle and D. R. Sands
Favorable
A. Morphology
Unfavorable
Fig. 37.1 Algorithm for local therapy for rectal cancer. TAE transanal excision, TEM transanal endoscopic microsur-
gery, TAMIS transanal minimally invasive surgery, CRT chemoradiation therapy
Table 37.1 The incidence of lymph node metastasis
based on T-stage of rectal cancer
T stage Incidence (%)
1 0–12
2 22–28
3 36
4 53
B. Staging
T3 Any N
T1/2 N0
LV1, poor dif,
tumor budding
T1N0
F. TAE
G. TEM
H. TAMIS
Radical resection
C. Histology
Favorable
T2 N0+
Poor candidate
for resection
E. Local excision + CRT
D. Local excision
D. Those rectal cancers that meet the criteria
from [A], [B], and [C] are candidates for local
excision. For all methods of local excision the
patient should receive full mechanical cathartic
bowel prep. The patient should be positioned
according to the location of the tumor so that it
is in the inferior aspect of the working eld. For
example the prone jackknife position is best
node metastasis. In patients with lymphovascular invasion (LVI) the incidence of
lymph node metastasis is 31% vs 17% in
those patients without lymphovascular invasion. In addition poorly differentiated
tumors have a higher rate of lymph node
metastasis at 50% compared to moderate
and well differentiated cancers (30% and
13% respectively). Lastly, the presence of
tumor budding has been shown to be a predictor of lymph node metastasis with an
odds ratio of 5.1–5.8. Based on these data
only those rectal cancers that are well differentiated with no tumor budding or lymphovascular invasion should be considered
for local excision. In a recent meta-analysis
of histopathological predictors of lymph
node invasion, 30,000 patients were evaluated for 12 pathologic risk factors. Statistical
signicance was reached for tumor stage,
differentiation, budding, lymphovascular
invasion and differentiation at the invasive
front. It has been shown as well that the
combination of poor differentiation and vascular invasion can have as high as 65% incidence of lymph node invasion for T1 lesions.
Careful consideration of pathologic risk factors is a must prior to local excision.
for anterior tumors, whereas lithotomy posi-
tion is preferred for posterior tumors lithotomy
and for decubitus contralateral position for lat-
eral tumors (Fig.37.2). It is necessary to per-
form a full thickness excision for rectal cancer.
The author recommends closure of all defects
following excision. It is not necessary to close
those defects below the peritoneal reection.
However, it is good practice especially when
doing TEM and TAMIS to perform closure of
the defect to ensure that this skill is perfected
in the event of peritoneal entry. The surgeon
should also consider whether or not the patient
has received preoperative radiation as it may
impede wound healing. In this case the sur-
geon may opt not to close a rectal defect below
the peritoneal reection.
E. The risk of lymph node metastasis is higher
in patients with T2 rectal cancer compared to
T1 cancers. Several studies have investigated
the effectiveness of neoadjuvant radiation in
addition to local excision for T2 cancers. The
ACOSOG Z6041 trial evaluated patients with
T2N0 disease treated with local excision and
radiation therapy. Recurrence was noted in 7
of 84 patients (2 local and 5 distant) after an
average follow up of 4.2years with overall
survival of 96% at 3 years. Adequate evi-
dorsosacral position
37 Rectal Cancer: Local Therapy
291
a
12.00
9.00 3.00
right lateral recumbent position
6.00
lithotomy position
b
6.00 h
Tumor
front wall
12.00 h
left lateral recumbent position
6.00 h
c
9.00 h
Fig. 37.2 The patient should be positioned according to
the location of the tumor so that it is in the inferior aspect
of the working eld. (a) For posterior tumors lithotomy;
dence comparing neoadjuvant radiation plus
local excision to radical resection is still lacking and traditional resection remains the gold
standard. However, local excision is an option
for those patients who are poor candidates for
an extensive operation and those who refuse
radical surgery. Local excision in patients
with more advanced disease following radiation therapy should be limited to those who
are not candidates for radical resection or
those in the setting of a formal trial.
(b) For anterior tumors, prone jack-knife; (c) For lateral
tumors decubitus position
Local Excision Techniques
(Refer toTable 37.2)
Local excision can be performed either in the
standard transanal fashion or through one of the
transanal endoscopic surgery (TES) platforms:
Transanal endoscopic microsurgery (TEM),
transanal endoscopic operations (TEO), or transanal minimally invasive surgery (TAMIS).
292
D. M. Lisle and D. R. Sands
F. Transanal excision (TAE): An anal retractor is
used to obtain adequate visualization of the
tumor. If necessary sutures can be placed above
the proximal tumor margin to prolapse the
tumor and improve visualization. Next, the line
of dissection is marked by circumferentially
scoring the rectal mucosa with electrocautery
for 1–2 cm around the tumor margin. A full
thickness excision down to the perirectal fat is
then carried out using electrocautery along the
previously marked line of dissection. The
defect is then transversely closed using interrupted absorbable suture. For anterior cancers,
it is important to be mindful of the vagina in
females. A bimanual exam should be intermittently performed throughout the procedure to
Table 37.2 Anatomical Considerations in selecting
method of local excision
Technique Utilization
TAE (Transanal excision)
[F]
TEM (Transanal endoscopic
microsurgery) [G]
TEM or TAMIS (transanal
minimally invasive surgery)
[H]
Small distal rectal
cancer [I]
Larger cancers above
the rst rectal valve [J]
Smaller cancers at or
below the rst rectal
valve [K]
gauge thickness and prevent dissection into the
vaginal wall. This technique is best for small
tumors at the level of the dentate line.
G. Transanal endoscopic surgery (TES):
Transanal endoscopic surgery (TES) is a
generic term used to include all of the various
transanal endoscopic surgical platforms and
techniques. The original modality, transanal
endoscopic microsurgery (TEM) utilizes an
operating platform containing a rigid procto-
scope and endoluminal insufation to pro-
vide stable pneumodistension of the rectum
for improved visualization. The proctoscope
is 4cm in diameter and is available in both 12
and 20cm lengths depending on the location
of the rectal tumor. A laparoscopic camera is
inserted through the proctoscope to display
the image on a screen. Alternatively, the sur-
geon can look through the stereoscopic eye
piece attached to the platform which provides
a 3D image through the proctoscope. Three
5 mm working ports exist on the platform
where angulated instruments similar to lapa-
roscopic instruments can be introduced for
the dissection (Fig.37.3). Patient positioning
is important in TEM surgery as the optics are
Fig. 37.3 Three 5mm
working ports exist on
the platform where
angulated instruments
similar to laparoscopic
instruments can be
introduced for the
dissection
37 Rectal Cancer: Local Therapy
293
xed with the platform. The patient must be
positioned so that the rectal mass is in the
inferior aspect of the working eld. Therefore,
patients with anterior rectal masses are placed
in prone jack-knife position and patients with
posterior masses are placed in lithotomy. Left
or right lateral decubitus positioning is used
for lateral lesions. The anus is gradually
dilated and the proctoscope is introduced into
the rectum. Once the mass has been identied
and centered in the eld of vision, the platform is xed in place to the OR table using
the multijointed Martin arm (Medline
Industries Inc) (Fig. 37.4). Cautery is then
attached to one of the 5mm instruments (needle tip, hook or spatula) and a line of dissection is marked 1cm from the tumor border
circumferentially by scoring the mucosa. A
grasper can be inserted in the other port site to
help retract the tumor towards the eld of
vision and improve visualization. A full
thickness excision down to the perirectal fat
is then carried out using the previously
marked line of dissection as a guide. The
tumor is removed by disconnecting the platform faceplate and is oriented and sent to
pathology. Next, the defect should be closed
transversely. For a large defect a suture can be
placed in the middle of the wound to reapproximate the edges and remove tension
(Fig.37.5). The remaining defect can then be
closed with 2 running sutures. A clip applier
is utilized and obviates the need for knot
tying in a conned space. Like TEM, trans-
anal endoscopic operating also utilizes a rigid
platform.
H. Transanal Minimally Invasive Surgery
(TAMIS): Similar in theory to TEM surgery,
TAMIS also utilizes endoluminal insufa-
tion to distend the rectum and improve visu-
Fig. 37.4 Once the mass has been identied and centered
in the eld of vision, the platform is xed in place to the
operating room table using the multijointed Martin arm
(Medline Industries Inc. Medford, NJ)
Fig. 37.5 For a large defect, a suture can be placed in the middle of the wound to reapproximate the edges and remove
tension