When addressing the issue of rectal cancer treatment, four major objectives are uniformly pursued: (a) cure—including primary local resection with negative margins and subsequent prevention of locoregional (LR) and distant recurrence, (b) decreased morbidity and mortality, (c) prevention of sexual and urinary dysfunction—as manifested by erectile dysfunction, retrograde ejaculation, vaginal dryness, dyspareunia, and difficulty voiding, and (d) maintenance of intestinal continuity/avoidance of a permanent stoma. Currently, despite the advances in chemotherapeutics, biologics, and radiation therapy, surgery is the primary modality to achieve these goals.

Current standard practice, based on preoperative staging, either with endorectal ultrasonography or magnetic resonance imaging, recommends low anterior resection (LAR) or abdominoperineal resection (APR) for most advanced (i.e., T3 or N+) distal lesions, within 0-5 cm above the dentate line. All of the advances in rectal surgery have been integral to the advent of intersphincteric restorative proctocolectomy (IRP) while continuing to meet the above primary objectives. In this procedure, the internal anal sphincter—a continuation of the rectal wall—is completely or partially excised to obtain the necessary full-thickness distal resection margin (1). Subsequent coloanal anastomosis to the remaining sphincter complex thereby restores intestinal continuity, with a goal of improved quality of life while preserving oncologic and functional outcomes. With these refinements and improvements in both neoadjuvant chemoradiation therapy and surgical techniques, patients now have another option available for sphincter preservation.

Due to the inherent morbidity associated with a permanent stoma (2,3), a restorative proctocolectomy may be offered to all patients with tumors that are amenable to the procedure. The decision to perform a restorative procedure should be made in conjunction with the patient after discussing the likely postoperative oncologic and functional outcomes. Whereas involvement of the internal sphincter by invasive disease should not be viewed as a contraindication to intersphincteric resection (4), invasion of the external sphincter or the musculature of the pelvic floor would make the disease incurable by IRP. A digital rectal examination that shows fixation of the tumor should also be considered a contraindication as it likely means that the tumor has broken through the intersphincteric plane and has fixed the internal sphincter—an embryological derivative and continuation of the rectal wall—to the external sphincter or the pelvic floor musculature (5,6). Such disease would be better managed by APR. A preoperative pelvic magnetic resonance imaging or endoanal ultrasound is instrumental in assessing the extent of tumor spread. Indeed, any tumor that has sphincter involvement, prior to the use of neoadjuvant combined modality therapy, should be excluded from an IRP and treated by a standard APR, despite improvement after therapy. Tumors that respond with downstaging and/or down-sizing after neoadjuvant chemoradiation therapy generally would make patients candidates for LAR/IRP. A chest X-ray and a computed tomography scan of the abdomen and pelvis should be performed to rule out stage IV metastatic disease. In the case of low rectal tumors, care must be taken to examine the groins for evidence of inguinal lymphadenopathy (7). The results of these preoperative evaluations, in conjunction with those following neoadjuvant therapy, should be used to determine the distal margin of resection (8) and potential for resection with maintenance of intestinal continuity/sphincter preservation.

Body habitus also plays a significant role in operative decision making. Ideally, the patient should not be obese (body mass index [BMI] <30–32). Patients that are males, have a narrow pelvis, or a long anal canal may also make it more difficult to perform an ideal, oncologic resection. Indeed, an IRP is more likely to be performed in patients that are male, have distal tumors, or increased BMI due to difficulty introducing stapling devices (for LAR).

It is also important to determine the patient’s preoperative continence. This assessment can be made by history, digital rectal examination, manometry, or a combination of these methods. In patients with good sphincter function on digital rectal examination but recent development of clinical incontinence, the dysfunction may be attributable to the neoplastic process, and it is reasonable to expect that they may benefit from an IRP. A validated incontinence score should be used. Patients with severe preoperative incontinence may be better served with a permanent stoma. However, these patients may benefit from an intersphincteric non-restorative proctocolectomy due to improved healing of the pelvic floor compared to APR, especially after undergoing neoadjuvant chemoradiation therapy. Though age per se is not an exclusion criterion, generally older patients have decreased sphincter tone and also less musculature needed for fecal control after undergoing radiation therapy and internal sphincter resection.

There are certain exclusion criteria that are generally accepted when evaluating ideal candidates for IRP: involvement of the external sphincter by tumor, inadequate distal margin (<1–2 cm), poor preoperative (or anticipated postoperative) sphincter function, patient preference, or an initial, pre-neoadjuvant uT3 lesion with external sphincter complex involvement (1). When looking at a nationwide database, factors that were noted to be independent predictors of sphincter preservation included younger age, proximal lesions, non-fixed lesions, and institution (9). Though not specifically addressed, individual training technique and outcomes are likely to be attributable to the success of an IRP. One cannot stress enough the importance, as with any procedure,
that specialty training and experience is mandatory for selecting and then completing these procedures. There is a learning curve, which is longer when the procedure is performed laparoscopically. Furthermore, a multi- or interdisciplinary approach to evaluation and selection of these patients may help in the postoperative period.

Various descriptions of intersphincteric restorative proctectomy have been presented in literature over the past 40 years (10,11,12). This extended resection for rectal malignancies is predicated on the knowledge that rectal tumor infiltration is initially limited by an embryonic plane between the visceral structures and the surrounding somatic skeletal muscles of the pelvic floor (13). An IRP attempts to rid the patient of disease while the tumor is still confined to this envelop. Throughout the dissection, particular attention is paid to minimize the damage to the sympathetic and parasympathetic fibers that are involved in bladder function and sexual potency. While damage to the sympathetic fibers leads to a decreased ability to attain orgasm, parasympathetic or combined damage results in impotence in men and vaginal dryness in women, manifesting as dyspareunia (14).

The author’s and editor’s preferences are for routine temporary diversion of all patients that undergo IRP. There remains some controversy about the role of diversion in rectal surgery due to the morbidity associated with a stoma as well as a second surgery to reverse it. In our experience, as in the experience of others, the increased salvage rate, decreased rate of reoperation, and decreased clinical significance of anastomotic failures in patients with diverted stomas makes the diverting procedure justifiable (15).

Although there is one randomized prospective trial that shows decreased morbidity in terms of postoperative ileus and small bowel obstructions with a diverting transverse loop colostomy (16), our preference is to utilize a diverting loop ileostomy. As the splenic flexure is often mobilized to provide adequate length for a coloanal anastomosis during an IRP, maturing a transverse loop colostomy becomes significantly more difficult than a diverting loop ileostomy. The operation to reverse a loop ileostomy is also much easier with decreased postoperative morbidity in terms of wound infection and abdominal wall hernia formation (17).

The anastomosis is studied 6 weeks later and if the results are satisfactory, the diversion is reversed (4).

In the setting of more distal tumors requiring IRP, our preference is to perform a complete laparoscopic total mesorectal excision (TME). Based on numerous trials, and also summarized by position statements from the American Society of Colon & Rectal Surgeons and the Society of American Gastrointestinal and Endoscopic Surgeons, laparoscopic techniques for curable colon cancer have been deemed to be a safe alternative when correct oncological techniques are followed. However, it is critically important to emphasize that a laparoscopic approach to rectal cancer is not a simple procedure, and that it requires proper training and experience in advanced minimally invasive surgery (18). Most of the data presented are based upon national data evaluated laparoscopic colon surgery and extrapolated based on multicenter experience with laparoscopic rectal cancer surgery. There is currently an American College of Surgeons Oncology Group trial underway evaluating oncological outcomes of rectal cancer surgery and operative approach—open, laparoscopic, and robotic (ACOSOG Z6051).

The procedure may conveniently be broken down into seven distinct steps: (a) mobilization of the sigmoid colon, left colon, and splenic flexure, (b) high intracorporeal vascular division of the inferior mesenteric artery and vein, (c) sharp TME, (d) intersphincteric distal dissection by the abdominal approach (if possible), (e) transperineal transection/intrasphincteric dissection and excision of the rectosigmoid, (f) extracorporeal transperineal creation and anastomosis of a reservoir, and (g) temporary diversion. Below is described the laparoscopic technique for an IRP.

The patient is placed in a modified lithotomy position and both legs are secured in Allen stirrups. Intraoperative evaluation of the rectal tumor is performed by digital rectal examination and rigid proctosigmoidoscopy to determine resectability and the site of distal resection. The rectum is then irrigated with a cytocidal solution of diluted Betadine. Both the abdomen and perineum are prepped and draped in a sterile manner. In females, the vagina is also sterilely prepped. Cystoscopy and bilateral ureteral catheter placement may be helpful in the setting of an irradiated pelvis.

Peritoneal access is obtained utilizing the open Hassan technique by a 1 cm supraumbilical incision. Upon obtaining pneumoperitoneum, a 10 mm 30-degree scope is utilized to perform a diagnostic laparoscopy. Particular attention is paid to the liver surface as well as the surface of the peritoneum to evaluate for metastatic disease. A 10/12 mm is placed in the right lower quadrant about 2 cm medial and 2 cm cephalad from the anterior superior iliac spine. An additional 5 mm port is placed in the right upper quadrant about 8 cm cephalad from the previous right lower quadrant port. A final 5 mm port may be placed in the left lower quadrant if needed for later use. This port can help with retraction of the rectum out of the pelvis, defining the anterior dissection plane, and in mobilization of the splenic flexure.

With the patient in slight Trendelenburg and airplaned to the right, the left lateral attachments of the sigmoid to the peritoneum are dissected free utilizing an ultrasonic dissector. Though some surgeons have used energized shears/electrocautery devices, the authors feel that an ultrasonic dissector may have a role in later portions of the case and maintenance of hemostasis. Care is taken to identify the left ureter and to preserve its posterolateral position. The descending colon is mobilized by freeing its lateral abdominal wall attachments along the line of Toldt. This dissection is carried proximally to the splenic flexure. The patient is then placed in slight reverse Trendelenburg and starting approximately halfway between the hepatic flexure and the falciform ligament, the gastrocolic omentum and its attachments to the transverse colon are divided. Dissection is carried out distally toward the previous dissection plane. The splenic flexure is thus completely and fully mobilized.

Placing the patient back in Trendelenburg, a high ligation of the inferior mesenteric artery (IMA) is performed. The relative anatomy of the sympathetic nerves in this region must be kept in mind while performing the next segment of the dissection. The superior hypogastric plexus and the origin of the hypogastric nerves overlie the aorta and the sacrum. They lie behind the IMA as it travels toward the rectum. These sympathetic fibers can sometimes be incorporated in the IMA pedicle if ligation of the IMA is performed too close to its origin from the aorta (14).

With the sigmoid colon on stretch and the patient airplaned to the right, mesenteric dissection is continued proximally until the vascular pedicle containing the IMA is identified. A window is created around the IMA. High ligation of the IMA is then performed just distal to its takeoff from the aorta. The author prefers to utilize a vascular stapling device for this ligation. The inferior mesenteric vein is also dissected free and divided using another firing of the vascular stapler or ultrasonic dissector. These maneuvers allow enough proximal colon length to perform reconstruction with a tension-free anastomosis.

Attention is then turned to the sacral promontory and a sharp TME is performed in the bloodless plane. The plane is maximally visualized by lateral manipulation performed
with the aid of the left lower quadrant abdominal port site and cephalad-anterior retraction of the rectum performed by the right upper quadrant port site. Both hypogastric nerves are identified and preserved. Dissection is carried out initially posteriorly, followed by laterally and finally anteriorly. Care must be taken to find the correct plane of dissection, described by Heald (13) as the “holy plane of rectal surgery,” just outside the fascia propria as the hypogastric nerves pass tangentially to it and medial to the ureter.

The inferior hemorrhoidal plexus (IHP) sends delicate branches to the rectum that travel in the lateral ligaments. The routine use of large clamps to ligate the lateral ligaments in an attempt to avoid hemorrhage from the middle rectal artery is unnecessary as this vessel is found in only 20% of patients. Utilization of these large clamps may increase the risk of damaging the IHP (19,20). We do not routinely include the entirety of Denonvilliers’ fascia (believed to be the conglomerate of two layers of the most distal pelvic peritoneum after the space within the layers is obliterated during embryogenesis) in our surgical specimen unless there is reason to believe that it would be required to obtain an R0 resection such as with an anterior lesion.

Care must be taken not to damage the delicate cavernosal fibers while performing the anterolateral separation of the distal rectum from the prostate and the seminal vesicles during both the abdominal and perineal portions of this dissection. The fibers are highly perceptible to damage as evidenced by case reports of patients suffering from neurogenic impotence after injection of sclerosant in too deep of a plane as attempted therapy for anteriorly located hemorrhoids (21). These fibers cannot be visualized, making knowledge of their location and pathway particularly crucial. After exiting from their sacral roots, they pass from the pelvis anterolateral to the rectum on their way to pierce the urogenital diaphragm before entering the corpora (14). Damage can be avoided by performing delicate and avoiding overaggressive rectal dissection at the 2 and 10 O’clock positions, as this is where the cavernosal fibers are at greatest risk. Laparoscopy aids in this dissection by affording a high definition and magnified view of the dissection planes with minimal traction artifact. This dissection is carried down to and past the levator plate and into the intersphincteric space.

Following this step, a loop of terminal ileum approximately 25 cm proximal to the ileocecal valve is exteriorized to fashion a loop ileostomy. It is brought out through the abdominal wall at the area previously marked by the stoma nurse. A mesenteric window is created at the apex of the loop and a standard stoma bridge rod is placed within this mesenteric window and sutured into place to prevent the small bowel from reducing back into the peritoneum.

Different definitions regarding the types of intersphincteric resections are abound (22,23). There is, however, uniformity in describing the total intersphincteric resection. The distal resection includes the complete internal anal sphincter complex by dissection at the level of the intersphincteric groove. The subtotal intersphincteric resection transects the internal sphincter musculature by choosing a dissection line between the dentate and the level of the more distal intersphincteric groove. A partial intersphincteric resection incorporates a distal line of dissection at or above the dentate. Occasionally, depending on the size/location of the tumor, a non-circumferential/partial internal sphincter resection may be performed.

At the beginning of the perineal dissection, a decision must be made as to the distal extent of the resection specimen. Although current literature suggests that a negative margin of less than 1 cm does not impair oncologic outcomes, these studies are able to make such claims in patients with locally advanced cancers only (24). If an attempt to perform a partial intersphincteric resection is to be made, then the author prefers to start his plane of dissection at least 1 cm distal to the furthest extent of the tumor, if not ideally 2 cm. If this is not possible or if there is preoperative evidence of internal sphincter involvement, a complete/total intersphincteric resection is advised. In such a situation, the distal plane of the resection should be started at the level of the intersphincteric groove, which may be marked by the white line of Hilton.

Once this decision has been made, a self-retaining retractor (Lone Star Retractor®, Lone Star Medical Products Inc, Houston, TX, USA) is utilized for effacement and retraction of the anal canal. Electrocautery is utilized to perform a circumferential mucosal excision at a level at least 1 cm distal to the lesion. This is extended deep past the internal sphincter muscle until the intersphincteric plane is encountered. The anal orifice (or distal resection margin) may be sutured close and the dissection is continued proximally staying in the plane within the smooth and striated muscles. We find it helpful to begin the dissection posterior and lateral before dissecting anterior as the intersphincteric plane is easier to identify in these locations. During this part of the dissection, care must be taken to avoid compromising Denonvilliers’ fascia as damage to the cavernosal fibers on the other side will usually lead to sexual dysfunction. Continued dissection in these planes eventually leads to communication with the abdominal dissection. At this point, therefore, the colon and rectum are completely free and the specimen is able to be brought out per the anus. Using two bowel clamps to avoid fecal contamination, the colon is divided at an area proximal to the division of the IMA. It is sent for frozen section analysis to evaluate for distal and circumferential margins. If the margins are positive, more tissue is excised until negative margins are obtained (12,25,26). In certain cases, the procedure is converted to an APR.

A coloanal anastomosis is then performed. Techniques for the various forms of restorative anastomoses are described below. Our preference is to perform a Baker-type side-to-end anastomosis (27) when a colonic J-pouch (CJP) cannot fit or be constructed. The Lone Star retractor is removed. To reduce the risk of tumor implantation and subsequent local recurrence, cytocidal washout is performed. The puncture sites of the Lone Star retractor are also irrigated as there have been reports of local recurrence at its puncture sites (28). A rolled up hemostatic foam is placed within the neorectum.

We then return to the abdomen and perform a diagnostic laparoscopy noting the tension free anastomosis. A drain is guided behind the neorectum and brought out through the left lower quadrant laparoscopic port site. All laparoscopic port sites are removed under direct visualization and the pneumoperitoneum is released. Fascia and skin incisions are closed and the diverting loop ileostomy (step 7) is matured in the standard manner. The diverting stoma is reversed with reestablishment of intestinal continuity performed after completion of postoperative adjuvant therapy. Generally, clinical, endoscopic, and radiological examination of the anastomosis is performed prior to reversal.