Clinical outcome of intersphincteric resection for ultra-low rectal cancer

Robotic Intersphincteric Resection for Low Rectal Cancer: Technical Controversies and a Systematic Review on the Perioperative, Oncological, and Functional Outcomes

Intersphincteric resection (ISR) is the ultimate anus-sparing technique for low rectal cancer and is considered an oncologically safe alternative to abdominoperineal resection. The application of the robotic approach to ISR (RISR) has been described by few specialized surgical teams with several differences regarding approach and technique. This review aims to discuss the technical aspects of RISR by evaluating point by point each surgical controversy. Moreover, a systematic review was performed to report the perioperative, oncological, and functional outcomes of RISR. Postoperative morbidities after RISR are acceptable. RISR allows adequate surgical margins and adequate oncological outcomes. RISR may result in severe bowel and genitourinary dysfunction affecting the quality of life in a portion of patients.

Anus-Preserving Surgery in Advanced Low-Lying Rectal Cancer: A Perspective on Oncological Safety of Intersphincteric Resection

The surgical management of low-lying rectal cancer, within 5 cm from the anal verge (AV), is challenging due to the possibility, or not, to preserve the anus with its sphincter muscles maintaining oncological safety. The standardization of total mesorectal excision, the adoption of neoadjuvant chemoradiotherapy, the implementation of rectal magnetic resonance imaging, and the evolution of mechanical staplers have increased the rate of anus-preserving surgeries. Moreover, extensive anatomy and physiology studies have increased the understanding of the complexity of the deep pelvis. Intersphincteric resection (ISR) was introduced nearly three decades ago as the ultimate anus-preserving surgery. The definition and indication of ISR have changed over time. The adoption of the robotic platform provides excellent perioperative results with no differences in oncological outcomes. Pushing the boundaries of anus-preserving surgeries has risen doubts on oncological safety in order to preserve function. This review critically discusses the oncological safety of ISR by evaluating the anatomical characteristics of the deep pelvis, the clinical indications, the role of distal and circumferential resection margins, the role of the neoadjuvant chemoradiotherapy, the outcomes between surgical approaches (open, laparoscopic, and robotic), the comparison with abdominoperineal resection, the risk factors for oncological outcomes and local recurrence, the patterns of local recurrences after ISR, considerations on functional outcomes after ISR, and learning curve and surgical education on ISR.

Narrow pelvic inlet plane area and obesity as risk factors for anastomotic leakage after intersphincteric resection

BACKGROUND

Intersphincteric resection (ISR) has been increasingly used as the ultimate sphincter-preserving procedure in extremely low rectal cancer. The most critical complication of this technique is anastomotic leakage. The incidence rate of anastomotic leakage after ISR has been reported to range from 5.1% to 20%.

AIM

To investigate risk factors for anastomotic leakage after ISR based on clinicopathological variables and pelvimetry.

METHODS

This study was conducted at Department of Colorectal Surgery, Japanese Red Cross Medical Center, Tokyo, Japan, with a total of 117 patients. We enrolled 117 patients with extremely low rectal cancer who underwent laparotomic and laparoscopic ISRs at our hospital. We conducted retrospective univariate and multivariate regression analyses on 33 items to elucidate the risk factors for anastomotic leakage after ISR. Pelvic dimensions were measured using three-dimensional reconstruction of computed tomography images. The optimal cutoff value of the pelvic inlet plane area that predicts anastomotic leakage was determined using a receiver operating characteristic (ROC) curve.

RESULTS

We observed anastomotic leakage in 10 (8.5%) of the 117 patients. In the multivariate analysis, we identified high body mass index (odds ratio 1.674; 95% confidence interval: 1.087-2.58; P = 0.019) and smaller pelvic inlet plane area (odds ratio 0.998; 95% confidence interval: 0.997-0.999; P = 0.012) as statistically significant risk factors for anastomotic leakage. According to the receiver operating characteristic curves, the optimal cutoff value of the pelvic inlet plane area was 10074 mm². Narrow pelvic inlet plane area (≤ 10074 mm²) predicted anastomotic leakage with a sensitivity of 90%, a specificity of 85.9%, and an accuracy of 86.3%.

CONCLUSION

Narrow pelvic inlet and obesity were independent risk factors for anastomotic leakage after ISR. Anastomotic leakage after ISR may be predicted from a narrow pelvic inlet plane area (≤ 10074 mm²).

Precision functional sphincter-preserving surgery (PPS) for ultralow rectal cancer: a natural orifice specimen extraction (NOSE) surgery technique

BACKGROUND

In patients with ultralow rectal cancer, surgical resection of the tumor without impairing sphincter function remains a technical challenge. The purpose of this study was to describe a new technique of transanal natural orifice specimen extraction (NOSE) surgery using our independently developed devices, aiming to achieve precise cancer resection and preserve sphincter function in patients with ultralow rectal cancer.

METHODS

Precision functional sphincter-preserving surgery (PPS) was performed on nineteen patients with ultralow rectal cancer between June 2019 and April 2020. With the help of our independently developed devices, surgeons directly and accurately removed the lower edge of the tumor and retained healthy rectal tissue on the nontumorous side. Hand-sewn anastomosis with a mattress suture was used to achieve sturdy anastomosis. Preoperative baseline characteristics, operative details, 90-day postoperative complications, costs, and anal function score at 6 months after surgery were documented.

RESULTS

Nineteen ultralow rectal cancer patients with a median distance to the dentate line of 2.0 cm successfully underwent PPS without serious postoperative complications. Six out of nineteen patients (31.6%) received a prophylactic stoma. The average cost was 62164.1 yuan. At 6 months after surgery, the average Wexner anal function score and the average Vaizey score were both 3 points.

CONCLUSIONS

PPS can be employed to precisely resect rectal tumors and preserve sphincter function in ultralow rectal cancer patients. The use of our devices enhanced surgical efficiency, reduced the need for prophylactic stoma, reduced surgery-related costs, and prevented abdominal surgical incisions.

Latest Advances in Intersphincteric Resection for Low Rectal Cancer

Background

Intersphincteric resection (ISR) has been a preferable alternative to abdominoperineal resection (APR) for anal preservation in patients with low rectal cancer. Laparoscopic ISR and robotic ISR have been widely used with the proposal of 2 cm or even 1 cm rule of distal free margin and the development of minimally invasive technology. The aim of this review was to describe the newest advancements of ISR.

Methods

A comprehensive literature review was performed to identify studies on ISR techniques, preoperative chemoradiotherapy (PCRT), complications, oncological outcomes, and functional outcomes and thereby to summarize relevant information and controversies involved in ISR.

Results

Although PCRT is employed to avoid positive circumferential resection margin (CRM) and decrease local recurrence, it tends to engender damage of anorectal function and patients' quality of life (QoL). Common complications after ISR include anastomotic leakage (AL), anastomotic stricture (AS), urinary retention, fistula, pelvic sepsis, and prolapse. CRM involvement is the most important predictor for local recurrence. Preoperative assessment and particularly rectal endosonography are essential for selecting suitable patients. Anal dysfunction is associated with age, PCRT, location and growth of anastomotic stoma, tumour stage, and resection of internal sphincter.

Conclusions

The ISR technique seems feasible for selected patients with low rectal cancer. However, the postoperative QoL as a result of functional disorder should be fully discussed with patients before surgery.

Intersphincteric resection for very low rectal cancer: A review of the updated literature

Intersphincteric resection (ISR) has rapidly increased worldwide including laparoscopic surgery. However, there are some concerns for the definition of ISR, surgical technique, oncological outcome, anal function, and quality of life (QoL). The aim of the present study is to evaluate those issues. A review of this surgical technique was carried out by searching English language literature of the PubMed online database and appropriate articles were identified. With regard to open‐ISR, the morbidity rate ranged from 7.5% to 38.3%, with lower mortality rates. Local recurrence rates varied widely from 0% to 22.7%, with a mean follow‐up duration of 40–94 months. Disease‐free and overall 5‐year survival rates were 68–86% and 76–97%, respectively. Those outcomes were equivalent to laparoscopic‐ISR. Surgical and oncological outcomes of ISR were generally acceptable. However, accurate evaluation of anal function and QoL was difficult because of a lack of standard assessment of various patient‐related factors. The surgical and oncological outcomes after ISR seem to be acceptable. The ISR technique seems to be valid as an alternative to abdominoperineal resection in selected patients with a very low rectal cancer. However, both necessity for ISR and expectations of QoL impairment as a result of functional disorder should be fully discussed with patients before surgery.

Necessary circumferential resection margins to prevent rectal cancer relapse after abdomino-peranal (intersphincteric) resection

PURPOSE

The purpose of this study was to determine the adequate circumferential resection margin (CRM) for abdomino-peranal (intersphincteric) resection (ISR) that would prevent the relapse of rectal cancers.

METHODS

The records of 41 cases that underwent curative ISR for rectal cancer were retrospectively reviewed. The relapse-free survival rates and overall survival rates were evaluated and correlated with the maximum depth of the inner muscularis layer reached during ISR (i.e., the radial margin [RM] and distal margin [DM]). Cases were divided into three groups based on the sizes of the RM and DM: (1) group A (RM >2 mm and DM >1.5 cm), (2) group B (RM >2 mm or DM >1.5 cm but not both), and (3) group C (RM <2 mm and DM <1.5 cm).

RESULTS

The relapse-free survival rates of the cases in group C were lower than those in the cases of group A or group B (p = 0.002 and 0.037, respectively). The resection margins required to prevent rectal cancer relapse were >2 mm for the RM and >1.5 cm for the DM. For these margins, the intersphincteric space had to be entered (i.e., between the internal and external anal sphincters).

CONCLUSION

It is critical to enter the intersphincteric space to ensure an adequate CRM (RM >2 mm and DM >1.5 cm) for preventing rectal cancer recurrence after ISR.

Long-term results of intersphincteric resection for low rectal cancer

BACKGROUND

The aim of this study is to investigate the long-term therapeutic outcome of intersphincteric resection (ISR) as the treatment of ultra-low rectal cancer.

METHODS

During January 2004 and October 2010, ISR was performed in 60 patients with ultra-low rectal cancer and their survival, local recurrence, and functional outcome were evaluated retrospectively.

RESULTS

A total of 60 patients with tumors at a median distance of 42 (range 30-50) mm from the anal verge underwent ISR. Three cases developed anastomotic leakage and two cases developed anastomotic stenosis postoperatively. After a median follow-up of 49 (range 18-90) months, local and distant recurrence occurred in six and four patients, respectively. Five-year overall and disease-free survival rates were 90.0% and 83.3%. Among them, the functional results of 53 patients suggested the mean stool frequency were 3.8 ± 1.3 (range 3-10) per 24 hr. According to Kirwan classification, good continence was shown in 73.6% of the patients.

CONCLUSION

This preliminary study indicated that ISR might be a candidate technique in treating patients with ultra-low rectal cancer and achieved satisfactory long-term results in functional and oncologic respects.

Intersphincteric resection for very low rectal cancer: a systematic review

Radical surgical treatment for very low rectal cancer near the anus has generally involved abdominoperineal resection. Various sphincter-saving operations have been developed for such tumors to optimize the patients' postoperative quality of life. Current protocols focus on intersphincteric resection (ISR), which differs from conventional hand-sewn coloanal anastomosis (CAA) after low anterior resection. However, the efficacy of ISR remains unclear. The surgical, oncologic, and functional outcomes after intersphincteric resection (ISR) were reviewed. This review of the current literature was conducted by searching the PubMed online database. Articles focusing specifically on conventional hand-sewn CAA were excluded from this study. The mean mortality rate is <2 %, and the mean morbidity rate ranges from 7.7 to 38.3 %. The mean local recurrence rate varies widely from 0 to 22.7 %, with a mean follow-up duration of 40-94 months. The mean disease-free and overall 5-year survival rates are 69-86 and 79-97 months, respectively. Functional outcomes are generally acceptable, but accurate evaluation is extremely difficult due to the absence of unified appraisal methods. ISR appears surgically, oncologically and functionally acceptable. However, more experience and better understanding of the oncology, anal physiology, and pelvic anatomy are necessary to achieve successful outcomes without complications, and to improve patient survival.

Laparoscopic intersphincteric resection with a SILS port for very low rectal cancer: a case report

Since intersphincteric resection (ISR) for rectal cancer was established in the 1990 s, this technique has been applied to very low rectal cancer. This procedure requires advanced techniques for anorectal surgery. However, it is indicated only for early lesions and should be as minimally invasive as possible. We describe a minimally invasive ISR with a single-incision laparoscopic surgery (SILS) port. Our case involves a 59-year-old man with hemorrhage from the rectum. Pathologic examination of the transanally resected specimen revealed that the tumor had invaded into the deeper submucosa. To minimize surgical incisions, a SILS port was utilized in place of a 10- and a 5-mm trocar. The SILS port was inserted through a 2.5 cm transverse incision in the right lower abdomen, where a diverting stoma would be created. Two flexible or straight forceps introduced through this port afforded an easier dissection of the rectum to the levator ani muscle, and transanal dissection of the internal sphincter was performed in the standard manner to connect with the abdominal dissection. The only postoperative incision other than a stoma and surgical drain was one 10-mm incision above the umbilicus. Our technique of ISR with the SILS port is a useful clinical application of minimally invasive surgery.

How low is low? Evolving approaches to sphincter-sparing resection techniques

Although advances in rectal cancer staging may ultimately be accurate enough to reliably exclude disease outside the rectal wall (thereby allowing local approaches to be more widely and safely applied) and advances in the use of neoadjuvant chemo- and radiation therapy may ultimately produce more "complete responders" that can be accurately identified and spared surgery altogether, as it stands, radical resection forms the basis of curative treatment for rectal cancer. However, the concepts that guide the surgeon in choosing the optimal approach in radical resection are changing. In the past, the decision as to how to proceed surgically with radical resection was based primarily on the level of the tumor above the anal verge or anorectal ring. The issue was primarily "How low is the tumor?" and "Is the distal margin safe?" A more modern approach focuses attention on achieving a negative circumferential margin despite what historically may seem to be a very minimal distal margin, the current issue is not "How low is the tumor?" so much as it is "How deep does the tumor go?". This shift in focus has been a major impetus in the evolution of sphincter sparing resection techniques.

Low-lying rectal cancer with anal canal involvement: abdominoperineal or low anterior resection after neoadjuvant chemoradiotherapy

BACKGROUND

Rectal cancer with anal involvement is typically treated with abdominoperineal resection (APR). However, patients treated with neoadjuvant chemoradiotherapy with good clinical response and tumor regression from the anus present a controversial management dilemma. This is a report of patients treated with low anterior resection (LAR) versus APR.

METHODS

Patients with T2-3N0-2M0 (IIA-IIIC) rectal cancer with anal canal involvement were eligible. Anal canal involvement was determined by sigmoidoscopy/colonoscopy or endoscopic ultrasound. Patients were treated in the prone position with the three-field technique to 45-50.4 Gy at 1.8 Gy/fraction given concurrently with 5-fluorouracil. Patients then underwent APR/LAR via total mesorectal excision 4-6 weeks after chemoradiotherapy. LAR was performed in patients with good sphincter function at presentation, in those with sufficient tumor regression away from anal canal to permit LAR, and in those compliant with close follow-up.

RESULTS

A total of 32 patients with rectal cancer with anal canal involvement were treated with neoadjuvant chemoradiotherapy. Local control was 85% and 89% for patients treated with APR and LAR, respectively. Overall survival was 76% and 86% in patients treated with APR and LAR, respectively. Pathologic complete response was seen in 24% of patients who underwent APR and 27% of patients who underwent LAR.

CONCLUSION

Rectal cancers with anal involvement with good clinical response after neoadjuvant chemoradiotherapy are typically treated with APR. However, LAR may be a feasible alternative, particularly in those with excellent clinical response to neoadjuvant treatment with sufficient tumor regression away from the anal canal. In these patients close follow-up is necessary, and APR may be reserved as salvage when needed.

Sphincter-sparing resection for rectal cancer

Although there is still a place for abdominoperineal resection in the treatment of rectal cancer, the state of the art is sphincter-preserving resection. Even for the lowest of rectal cancers, using a combination of neoadjuvant chemo/radiation, total mesorectal excision, and intersphincteric proctectomy and colonic J-pouch to anal anastomosis, sphincter preservation can be achieved for most patients. The key concept in pushing sphincter preservation forward has been the realization that the deep, circumferential, or lateral margin is all-important. Unless the rectal tumor involves the external sphincter muscle, there is no oncologic need to remove it, and following resection of the tumor, gastrointestinal tract continuity can be restored.

Extending the horizons of restorative rectal surgery: intersphincteric resection for low rectal cancer

OBJECTIVE

Radical resection of tumours of the distal rectum has generally entailed an abdominoperineal excision, but the recognition of shorter safe distal resection margins, neoadjuvant chemoradiotherapy and the application of the technique of intersphincteric resection (ISR) have led to the prospect of restorative surgery for patients with distally situated tumours. The present study examines the indications, techniques and outcomes following ISR.

METHOD

A literature search was performed to identify studies reporting outcomes following ISR for low rectal cancer. The outcomes of interest included short-term adverse events, functional and manometric results, postoperative quality of life and oncologic outcomes.

RESULTS

Twenty-one studies reflecting the experience of 13 units and 612 patients were included. Operative mortality following ISR was 1.6% (inter-unit range 0-5%) and anastomotic leak rate 10.5% (inter-unit range 0-48.4%). The pooled rate of local recurrence was 9.5% (range 0-31% between units) with an average 5-year survival of 81.5%. Most studies recorded a significant reduction in resting anal pressure but not squeeze pressure following surgery, but urgency was reported in up to 58.8% of patients. Functional outcomes and quality of life may be improved using colonic j-pouch reconstruction. The use of chemoradiotherapy can offer benefits in terms of oncologic result, but at the cost of worse functional outcomes.

CONCLUSION

Careful case selection and counselling is required if satisfactory results are to be achieved following ISR for low rectal cancers. In selected patients, however, the technique offers sphincter preserving surgery with acceptable oncologic and functional results.

Role of sphincter preserving surgery with neoadjuant chemoradiotherapy for locally advanced low rectal cancer

AIM: To evaluate the role of the sphincter preserving surgery with neoadjuvant chemoradiotherapy in locally advanced low rectal cancer.

METHODS: Forty-two patients with T3 and T4 low rectal cancer were treated by pre-operative radiotherapy to pelvis, 2 Gy daily up to 40-46 Gy in 4 weeks concomitantly with oral administration of capecitabine (CAP) at 1250 mg/m2 bid for 10 weeks (group A). Twenty-one patients were treated by the same chemoradiotherapy after operation (group B).

RESULTS: Neoadjuvant chemoradiotherapy (NCR) was successfully completed in group A. Among the 42 patients, tumor lesions disappeared in 5 cases, so they didn't receive operation. Curative resection was carried out in the remaining 37 patients, of which 33 received the sphincter-saving resection (SSR) and 4 received abdomino-perineal resection (APR). The rate of sphincter preservation was 89.2% in group A. Of the 21 patients in group B, 11 received SSR and 10 received APR. The rate of sphincter preservation was 52.4% in group B.

CONCLUSION: NCR shows high efficacy in tumor down-staging and shrinkage of tumor mass, and improves the resection rate and sphincter preservation.