Regardless of operative technique, the oncologic surgical principles remain the same. The concept of total mesorectal excision (TME) , as originally described by Richard Heald in the early 1980s, includes meticulous surgical dissection of the rectal mesentery and has been shown to increase overall survival and decrease local recurrence [31]. The open operation begins with mobilization of the descending and sigmoid colon from the lateral attachments at the white line of Toldt. The colon and its mesentery are mobilized medially off the retroperitoneum as the ureter is identified and protected. The splenic flexure is not usually taken down since an anastomosis will not be created. If additional length is required, the splenic flexure may be taken down and the inferior mesenteric vein ligated near the duodenal-jejunal flexure medially. The origin of the superior rectal artery off of the inferior mesenteric artery (IMA) is identified and is ligated at this point. The corresponding point on the descending colon represents the proximal resection margin, and the colon and adjacent mesentery are divided at this level (see Fig. 8.2). For minimally invasive approaches, a medial to lateral approach is often taken to isolate the superior rectal pedicle. This then facilitates a complete submesenteric dissection prior to the division of the remaining lateral attachments of the sigmoid and descending colon. Frequently, the descending colon is not immediately divided to allow traction on the rectum during minimally invasive pelvic dissection.

At this point, attention is directed toward pelvic dissection, and the patient is positioned in Trendelenburg position with the small intestines packed away for improved visualization. The rectal dissection is begun at the sacral promontory, and the retrorectal space is identified. A circumferential dissection of the rectum and mesorectum is performed as described in the chapter on total mesorectal excision. Laterally, care is taken to avoid injury to the internal iliac vein as well as the ureters at the pelvic brim. Posteriorly, care is taken to identify the hypogastric nerves as they course from the midline laterally; injury to these structures can result in retrograde ejaculation . Anteriorly, the anterior rectal wall is separated from the bladder and, in men, the prostate and seminal vesicles and, in women, the posterior vaginal wall along the fascia of Denonvillier (see Fig. 8.3). In most cases, dissection can be carried out posterior to Denonvillier’s fascia, but anterior dissection may be indicated to optimize circumferential margin for anterior-based rectal lesions.

Circumferential rectal dissection is then carried down to the pelvic floor at the level of the levator ani muscles. The lateral attachments are divided close to the mesorectum to avoid injury to the lateral nerve plexuses which could potentially contribute to impotence in men and bladder dysfunction. At this point, a critical technical step in APR must be considered. The historical literature typically demonstrates a significantly greater degree of radial margin positivity and corresponding rate of local recurrence in APR as compared to LAR [32, 33]. It has been theorized that this may be due to inadequate wide excision at the level of the pelvic floor.

Indeed circumferential rectal margin (CRM) status is a predictor of outcome and is considered an important surgical quality indicator. Of the 455 patients who underwent APR as part of the Dutch Rectal Cancer Trial , 29.6% had a positive CRM. Location of tumor was the most important predictor of CRM with anterior tumors being the most likely to have a positive CRM when compared to laterally located tumors (44% vs. 21%, p < 0.0001) [34]. Local recurrence rates of ~22 and ~5% have been reported for patients with positive and negative CRM, respectively [35]. Positive CRM has also been associated with increased rates of distant metastasis [35]. Quirke et al. found that the combination of a negative CRM and optimal TME offers the lowest chance for local recurrence (1% at 3 years) [36].

As such, there has been greater emphasis placed on achieving wide local excision of the levator ani muscles via a “cylindrical dissection ” via what has been referred to as extralevator abdominoperineal excision (ELAPE) [37]. From a procedural standpoint, the wide division of the levator ani muscles can be achieved from either the abdominal or perineal approach. Regardless of approach, the deep dissection should maintain a cylindrical shape to avoid “waistcoating” of the mesorectum at the level of the levator ani muscles (see Fig. 8.4). ELAPE has been shown to have improved CRM at the expense of a potential increase in wound and other complications [38].

The perineal portion of the procedure can be performed with the patient in either the lithotomy (Lloyd-Davies) or prone jackknife (Kraske) position . For the prone approach, upon completion of the abdominal portion, pelvic drains are placed, the wound closed, and the colostomy matured prior to repositioning the patient. Some authors claim that in prone position, exposure is improved along the anterior dissection plane and prostatic urethra leading to decreased operative time and blood loss [39, 40]. The lithotomy position requires no additional repositioning and offers the advantage of simultaneous access to both the abdomen and perineum, which in turn also offers the ability for a time-efficient two-team synchronous approach. Regardless, effective and safe extralevator resection is possible from either patient position and are considered equivalent [41–43].

The landmarks of the perineal resection are the coccyx posteriorly, the prostatic urethra anteriorly, and the ischiorectal fossae laterally (see Fig. 8.5). An extrasphincteric circumferential incision is made at the perineum, and an extralevator dissection continues the cylindrical shape. Posteriorly, the perineal dissection is first connected to the previously completed abdominal dissection immediately anterior to the coccyx. Subsequently, circumferential perineal extralevator dissection continues by transecting the levator ani muscles at their origin. The anterior rectal dissection is generally performed last to improve visibility and reduce chances for injury to the urethra in men and the vagina in women. Upon removal of the specimen, the perineal defect may be closed primarily or with flap reconstruction (see below) as indicated. The authors prefer the placement of a transabdominal closed suction drain. Some surgeons prefer transperineal placement; however, this has been associated with increased patient discomfort [44]. If not already completed, the midline incision is closed and the colostomy matured.

Unlike emergent situations when a colostomy is potentially temporary and reversible, the colostomy performed at the time of APR is permanent. As such, patients may live decades following curative APR, and special care should be given to perform a technically precise and meticulous end colostomy in order to avoid both short-term and lifelong complications.

Choosing a practical and functional location of the colostomy on the patient’s abdominal wall is essential to avoid the morbidity and diminished quality of life associated with poorly functioning ostomy appliances. The left-sided location should be chosen prior to surgery taking into consideration body habitus, skin folds when sitting, and patient preferences. The colostomy should be well within reach of the patient so he/she can independently empty and change the ostomy appliance . It should be located either above or below the belt line and skin folds, and previous scars should be avoided to prevent leakage from the appliance. Preoperative education and marking provided by a trained enterostomal therapist is valuable and can help prepare the patient for this life-altering situation.

Prior to closing the abdominal fascia, a 2–3-cm circular incision is made, the skin excised, and the tissues dissected down to the fascia. A fascial defect is made through the anterior and posterior rectus sheath. The distal colon is extracted through the rectus sheath, and the muscle fibers are split, rather than transect. As the distal colon is brought through the fascia to the skin, special care must be taken to avoid twisting of the colon or avulsion of the mesentery which may result in devascularization. The fascial opening should allow a snugly fit finger in addition to the bowel and its mesentery. The bowel should be externalized without tension to a point approximately 3 cm above the level of the skin.

Once the abdominal wall and skin closure is complete, the colostomy is matured by removing the staple line from the externalized bowel. The mucosa and mesentery are assessed to ensure preserved perfusion and viability. The mucosa is secured to the subcuticular layer of the skin using interrupted 3-0 or 4-0 absorbable sutures. The bowel wall should be everted such that the colostomy protrudes 1–2 cm above the skin to facilitate placement of the ostomy appliance.

Surgical approaches include open, laparoscopic-assisted, and robot-assisted techniques. Pivotal early studies such as the COST and the MRC CLASICC trials showed that the laparoscopic approach for colon cancer is oncologically comparable to open colon surgery [45–47]. However, given the additional complexity of rectal surgery, the data showing benefits for the laparoscopic approach for rectal cancer are not as definitive. The COLOR II trial has reported on the long-term results of laparoscopic rectal cancer surgery and shown no difference in the rates of local recurrence between laparoscopic and open surgery, overall. One interesting finding in the study was the fact that the rate of CRM positivity was significantly lower in the laparoscopic arm for patients with distal rectal cancer. However, this might be explained by the notably higher than expected rate of CRM positivity in the open arm. Long-term results of the ACOSOG Z6051 and ALaCaRT trials are awaited; however, neither study could establish the oncologic non-inferiority of laparoscopic surgery in the short term. However, short-term non-oncologic benefits of laparoscopic surgery have been demonstrated, including less intraoperative blood loss (200 vs. 400 ml, p < 0.0001), shorter hospital stay (8 vs. 9 days, p = 0.036), and decreased time for return of bowel function (2 vs. 3 days, p < 0.0001) [48]. The COREAN trial randomized patients with mid-rectal cancers to laparoscopic or open surgery and showed no difference in surgical specimen quality as measured by lymph node harvest, CRM, and macroscopic quality of TME [49]. They also showed shorter hospital stay and faster return of bowel function following laparoscopic rectal surgery. Despite the current data from prospective randomized control trials, there remains great interest for considering laparoscopic surgery for low rectal cancer with the caveat that long-term oncologic equivalency to open surgery has not been established.

Robot-assisted minimally invasive approaches to rectal cancer surgery have gained popularity in recent years due to the improved instrumentation and visualization. A meta-analysis by Yang et al. evaluated 16 studies comparing laparoscopic to robotic rectal cancer surgery and found that the robotic approach had lower blood loss and conversion rates but higher costs when compared to the laparoscopic approach. The two techniques were similar in terms of complications and early markers of surgical quality including CRM and lymph node harvest [50]. Nonetheless, large-scale prospective analyses that examine both clinical outcomes and cost-effectiveness remain necessary.

For patients who have locally advanced, nonmetastatic primary, or recurrent tumors, multivisceral resections may offer the best chance for cure. Pelvic exenteration traditionally involves en bloc removal of the rectum along with its adjacent pelvic organs which include the bladder and prostate in men and the bladder and uterus in women. Additional extended resections may also involve partial sacrectomy or partial vaginectomy . Yamada et al. demonstrated that 5-year survival rates were higher among patients with locally recurrent rectal cancer treated by curative-intent exenteration as compared to those who underwent palliative non-oncologic resection (22.9% vs. 0%, p = 0.0065) [51]. Law et al. observed that pelvic exenteration was associated with a high risk of perioperative morbidity (54%) and an overall 5-year mortality rate of 44% [52]. Multivisceral resection including sacropelvic resection can have good oncologic outcomes with 5-year disease-free survival rates in the range of 43% [53]. The preoperative evaluation should include high-quality imaging of the pelvis. Any concern for extra-rectal sacral, prostatic, bladder, or vaginal involvement warrants further investigation with MRI.

Sacral resection may be indicated in cases of primary or recurrent rectal cancer with posterior bony extension. Tumors at or below S3 are amenable to standard partial sacrectomy. Milne et al. reviewed 100 cases and found a high complication rate (74%) with 43% of these classified as major morbidity. Neurologic complications were increased if the resection was above the S3 level [54]. Among patients from Memorial Sloan Kettering who presented for abdominosacrectomy because of recurrent disease, their complication rate was 59%, and disease-free survival was 20% at 5 years [55]. For tumors at or above S2, a high sacrectomy is possible but carries a higher risk of neurologic complication, increased morbidity, and decreased disease-free survival [56, 57].

The use of a coordinated multidisciplinary team approach is critical for the management of rectal cancer and particularly important in the setting of locally advanced primary or recurrent rectal tumors. The integrated surgical team often includes involvement of specialists from urology, gynecology, plastic surgery, and/or neurosurgery.

The routine use of ureteral stents for the identification and prevention of ureteral injury during APR is controversial. There are no randomized trials evaluating the prophylactic use of ureteral stents during colorectal cancer surgery owing to the fact that the incidence of ureteral injury is so low [58]. A recent nationwide analysis using data from the Healthcare Cost and Utilization Project Nationwide Inpatient Sample reported that among all patients who suffered an iatrogenic ureteral injury, rectal cancer was the most common indication for surgery, yet ureteral injury only occurred in 7.6 per 1000 cases during APR [59]. Comparison studies have not shown a decrease in the incidence of ureteral injuries during colorectal surgery with the use of ureteral stents [58, 60], but some authors suggest that ureteral stents allow for more apparent intraoperative recognition of an injury [61, 62]. Furthermore, ureteral stent placements are not without complications . Complications from ureteral stents include transient hematuria, urinary tract infections, hydronephrosis, and reflex anuria [63, 64]. One study of 66 patients reported that hemodialysis was required in two patients due to anuria following ureteral stent placement [65]. In addition to potential complications, ureteral stent placement adds cost and operative time to each procedure [64, 65]. It is our practice to selectively use ureteral stents in those cases when dense pelvic adhesions are expected, such as in cases of prior pelvic surgery, remote pelvic radiation (external beam or brachytherapy), or recurrent bulky disease which appears to involve one or both ureters.

Perineal wound complications (including bleeding, infection, dehiscence, fistulae, perineal herniation, chronic pain, and delayed wound healing) occur in 16–41% of patients following APR [66, 67] and are, consequently, a major source of morbidity. These complications are exacerbated by neoadjuvant radiation, which roughly doubles the rate of perianal complications [66]. Patients with obesity and significant comorbidities are also at increased risk for perineal wound complications [67, 68]. Furthermore, depending on the location and extent of involvement, rectal tumors can invade the vagina, prostate, bladder, and/or coccyx, and en bloc resections can result in substantial soft tissue defects too large for primary closure. These issues are particularly pertinent in patients with recurrent anal cancer, as these patients almost universally receive external beam radiation as part of their primary treatment and often require wide perineal soft tissue excisions to obtain negative margins. That said, most perineal wounds following APR are amenable to primary closure; however, large perineal defects require plastic surgery reconstruction . While a complete discussion of the reconstruction techniques used is beyond the scope of this book, the four most common methods are introduced here.

As noted previously, during its infancy, APR was associated with substantial rates of perioperative morbidity and mortality. However, as with many complex operative procedures, the evolution of surgical, anesthetic, and antimicrobial techniques has resulted in substantial improvements in outcomes. In modern series, perioperative mortality rates are generally less than 2%. Nonetheless, APR remains a relatively morbid procedure with an overall complication rate of approximately 50% [89–91].

Immediate nonhealing of the perineal wound represents a spectrum of clinical significance ranging from superficial wound separation to pelvic abscess and sepsis and thus requires different management strategies [104]. Despite general improvements in surgical outcomes, postoperative perineal wound healing complications following APR remain a significant problem with rates ranging from 14% to as high as 50% [83, 105, 106].

Perineal wound complications are associated with substantial additional medical costs as a result of increased length of stay, hospital readmission, and home nursing care needs [104]. Additionally, Hawkins et al. noted by multivariate analysis that perineal wound dehiscence following APR was associated with a 1.7 times increase in the adjusted risk of death [107].