Robotic Surgery for Rectal Cancer: Operative Technique and Review of the Literature

A new era in surgical oncology: preliminary insights into the hinotori™ surgical robot system's role in rectal surgery using the double bipolar method

BACKGROUND

The da Vinci™ Surgical System, recognized as the leading surgical robotic platform globally, now faces competition from a growing number of new robotic surgical systems. With the expiration of key patents, innovative entrants have emerged, each offering unique features to address limitations and challenges in minimally invasive surgery. The hinotori™ Surgical Robot System (hinotori), developed in Japan and approved for clinical use in November 2022, represents one such entrant. This study demonstrates initial insights into the application of the hinotori in robot-assisted surgeries for patients with rectal neoplasms.

METHODS

The present study, conducted at a single institution, retrospectively reviewed 28 patients with rectal neoplasms treated with the hinotori from November 2022 to March 2024. The surgical technique involved placing five ports, including one for an assistant, and performing either total or tumor-specific mesorectal excision using the double bipolar method (DBM). The DBM uses two bipolar instruments depending on the situation, typically Maryland bipolar forceps on the right and Fenestrated bipolar forceps on the left, to allow precise dissection, hemostasis, and lymph node dissection.

RESULTS

The study group comprised 28 patients, half of whom were male. The median age was 62 years and the body mass index stood at 22.1 kg/m2. Distribution of clinical stages included eight at stage I, five at stage II, twelve at stage III, and three at stage IV. The majority, 26 patients (92.9%), underwent anterior resection using a double stapling technique. There were no intraoperative complications or conversions to other surgical approaches. The median operative time and cockpit time were 257 and 148 min, respectively. Blood loss was 15 mL. Postoperative complications were infrequent, with only one patient experiencing transient ileus. A median of 18 lymph nodes was retrieved, and no positive surgical margins were identified.

CONCLUSIONS

The introduction of the hinotori for rectal neoplasms appears to be safe and feasible, particularly when performed by experienced robotic surgeons. The double bipolar method enabled precise dissection and hemostasis, contributing to minimal blood loss and effective lymph node dissection.

Differences in the Difficulty of Accessing Various 3-Dimensional Locations Under Mirror-Image Conditions During Laparoscopic Surgery

BACKGROUND

Laparoscopic colon surgery frequently requires performing maneuvers under mirror-images conditions; the complexity differs depending on the surgical site location in the abdominal cavity. However, no previous reports have examined this.

METHODS

Eleven surgeons participated in this study. Operations were performed on 25 points placed at the bottom and sides of a laparoscopic training box under mirror-image conditions. The mean time-point required to operate at each point and variation between surgeons were evaluated.

RESULTS

When the right hand was used, time-points to touch the right side-superficial ends were 0.50 to 0.58 and 0.27 to 0.45 for the other sites. With the left hand, time-points to touch the left side-superficial ends were 0.58 to 0.63 and 0.28 to 0.51 for the other sites, indicating that the most difficult manipulation was at the proximal site of the surgical port. The variation in the difficulty according to the spots increased with a decrease in the surgeon's experience (right hand, r =-0.248; left hand, r =-0.491).

CONCLUSIONS

In performing laparoscopic surgery under mirror-image conditions, the technical difficulty varies by location, and operating in locations close to the forceps port is the most difficult.

Effect of Robotic Inferior Mesenteric Artery Ligation Level on Low Anterior Resection Syndrome in Rectum Cancer

Background: Life expectancy of patients with rectal cancer is increasing day by day with innovative treatments. Low anterior resection syndrome (LARS), which disrupts the comfort of life in these patients, has become a serious problem. We aimed to evaluate the effect of high ligation (HL) and low ligation (LL) techniques on LARS in rectal cancer surgery performed with the robotic method. Materials and Methods: The data of patients diagnosed with mid-distal rectal cancer between 2016 and 2021 who underwent robotic low anterior resection by the same team in the same center with neoadjuvant chemoradiotherapy were retrospectively evaluated. Patients were divided into two groups as those who underwent HL and LL procedures. Preoperative, 8 weeks after neoadjuvant treatment, 3 and 12 months after ileostomy closure were evaluated. Results: A total of 84 patients (41 HL, 43 LL) were included in the study. There was no statistically significant difference between the demographic characteristics and pathology data of the patients. Although there was a decrease in LARS scores after neoadjuvant treatment, there was a statistically significant difference between the two groups at 3 and 12 months after ileostomy closure (P: .001, P: .015). Conclusions: In patients who underwent robotic low anterior resection, there is a statistically significant difference in the LARS score in the first 1 year with the LL technique compared with that of the HL technique, and the LL technique has superiority in reducing the development of LARS between the two oncologically indistinguishable methods.

Preliminary comparative study of lower extremity pressure measurements under the conditions using former models and new lithotomy stirrups in rectal cancer surgery

BACKGROUND

This study aimed to investigate the effect of the use of new lithotomy stirrups-2 on the pressure dispersal on lower limbs, which may lead to the prevention of well-leg compartment syndrome (WLCS) and deep venous thrombosis (DVT), which are the most commonly associated adverse events with laparoscopic and robot-assisted rectal surgery.

METHODS

A total of 30 healthy participants were included in this study. The pressure (mmHg) applied on various lower limb muscles when using conventional lithotomy stirrups-1 and new type stirrups-2 was recorded in various lithotomy positions; 1) neutral position, 2) Trendelenburg position (15°) with a 0° right inferior tilt, and 3) Trendelenburg position (15°) with a 10° right inferior tilt. Using a special sensor pad named Palm Q®, and the average values were compared between two types of stirrups.

RESULTS

The use of new lithotomy stirrups-2 significantly reduced the pressure applied on the lower limb muscles in various lithotomy positions compared with the use of lithotomy stirrups-1. The most pressured lower limb muscle when using both lithotomy stirrups was the central soleus muscle, which is the most common site for the development of WLCS and DVT. In addition, when using the conventional lithotomy stirrups-1, the pressure was predominantly applied to the proximal soleus muscle; however, when using lithotomy stirrups-2, the pressure was shifted to the more distal soleus muscle.

CONCLUSION

These results suggest that the new lithotomy stirrups-2 is useful in reducing the pressure load on leg muscles, especially on the proximal to central soleus, and may reduce the incidence of WLCS and DVT after rectal surgery performed in the lithotomy position. Further clinical studies are needed to determine whether the use of lithotomy stirrups-2 prevents these complications in various clinical settings.

Robot-assisted laparoscopic surgery for rectal cancer in a patient with a horseshoe kidney: A case report

A 52-year-old, Japanese man presented to the hospital with a complaint of anal bleeding, and detailed examination resulted in a diagnosis of locally advanced rectal cancer. The patient underwent total neoadjuvant therapy followed by short-course radiation therapy and consolidation chemotherapy, which provided a partial response. After preoperative contrast-enhanced computed tomography showed a horseshoe kidney, robot-assisted, precise, laparoscopic, low anterior resection with D3 dissection and ileostomy construction was performed. The horseshoe renal isthmus was elevated surrounding the inferior mesenteric artery, and the left ureter and seminal vessels ran in front of the kidney. The hypogastric nerve traveled ventral to the horseshoe kidney. With robotic surgery, it was possible to perform more precise surgery while recognizing vascular and nerve anatomy in a rectal cancer patient with a horseshoe kidney due to good three-dimensional visibility and articulated forceps manipulation.

Evaluation of an established colorectal robotic programme at an NHS district general hospital: audit of outcomes and systematic review of published data

INTRODUCTION

Robotic-assisted surgery (RAS) offers potential advantages over traditional surgical approaches. This study aimed to assess outcomes from a district general hospital (DGH) robotic colorectal programme against published data.

MATERIALS AND METHODS

The robotic programme was established following simulator, dry/wet lab training, and proctoring. We performed a case series analysing technical, patient, and oncological outcomes extracted from a prospective database of colorectal RAS cases (2015-2022). A registered systematic review (PROSPERO CRD42022300773; PubMed, Web of Science, EMBASE) of single-centre colorectal series from established robotic centres (n>200 cases) was completed and compared to local data using descriptive summary statistics. Risk of bias assessment was performed using an adapted version of the Cochrane ROBINS-I tool.

RESULTS

Two hundred thirty-two RAS cases were performed including 122 anterior resections, 56 APERs, 19 rectopexies, and 15 Hartmann's procedures. The median duration was 325 (IQR 265-400) min. Blood loss was < 100 ml in 97% of cases with 2 (0.9%) cases converted to open. Complications (Clavien-Dindo 3-5) occurred in 19 (8%) patients, with 3 (1.3%) deaths in < 30 days. Length of stay was 7 (IQR 5-11) days. In 169 rectal cancer cases, there were 9 (5.3%) cases with a positive circumferential or distal margin and lymph node yield of 17 (IQR 13-24). A systematic review of 1648 abstracts identified 13 studies from established robotic centres, totaling 4930 cases, with technical, patient, and oncological outcomes comparable to our own case series.

CONCLUSIONS

Outcomes from our robotic colorectal programme at a UK DGH are comparable with the largest published case series from world-renowned centres. Training and proctoring together with rolling audit must accompany the expansion of robotic surgery to safeguard outcomes.

Feasibility and learning curve for robotic surgery in a small hospital: A retrospective cohort study

Robotic surgery rates, typified by the use of the da Vinci Surgical System, have increased in recent years. However, robotic surgery is mostly performed in large hospitals and has not been fully implemented in small hospitals. Therefore, we aimed to verify the feasibility of robotic surgery in small hospitals and verify the number of cases in which perioperative preparation for robotic surgery is stable by creating a learning curve in small hospitals. Forty robot-assisted rectal cancer surgeries performed in large and small hospitals by a surgeon with extensive experience in robotic surgery were validated. Draping and docking times were recorded as perioperative preparation times. Unexpected surgical interruptions, intraoperative adverse events, conversion to laparoscopic or open surgery, and postoperative complications were recorded. Cumulative sum analysis was used to derive the learning curve for perioperative preparation time. Draping times were significantly longer in the small hospital group (7 vs 10 minutes, P = .0002), while docking times were not significantly different (12 vs 13 minutes, P = .098). Surgical interruptions, intraoperative adverse events, and conversions were not observed in either group. There were no significant differences in the incidence of severe complications (25% [5/20] vs 5% [1/20], P = .184). In the small hospital group, phase I of the draping learning curve was completed in 4 cases, while phase I of the docking learning curve was completed in 7 cases. Robotic surgery is feasible for small hospitals, and the preoperative preparation time required for robotic surgery stabilizes relatively early.

Three-dimensional visualization of the total mesorectal excision plane for dissection in rectal cancer surgery and its ability to predict surgical difficulty

Total mesorectal excision (TME) for rectal cancer is often technically challenging. We aimed to develop a method for three-dimensional (3D) visualization of the TME dissection plane and to evaluate its ability to predict surgical difficulty. Sixty-six patients with lower rectal cancer who underwent robot-assisted surgery were retrospectively analyzed. A 3D TME dissection plane image for each case was reconstructed using Ziostation2. Subsequently, a novel index that reflects accessibility to the deep pelvis during TME, namely, the TME difficulty index, was defined and measured. Representative bony pelvimetry parameters and clinicopathological factors were also analyzed. The operative time for TME was used as an indicator of surgical difficulty. Univariate regression analysis revealed that sex, body mass index, mesorectal fat area, and TME difficulty index were associated with the operative time for TME, whereas bony pelvimetry parameters were not. Multivariate regression analysis found that TME difficulty index (β = - 0.398, P = 0.0025) and mesorectal fat area (β = 0.223, P = 0.045) had significant predictability for the operative time for TME. Compared with conventional bony pelvimetry parameters, the TME difficulty index and mesorectal fat area might be more useful in predicting the difficulty of rectal cancer surgery.

Incomplete lymphatic sealing around the inferior mesenteric artery is a risk factor for chylous ascites in robotic rectal cancer surgery

INTRODUCTION

Compared with laparoscopic surgery (LS), robotic surgery (RS) is considered to have acceptable outcomes in rectal cancer, but few reports have focused on chylous ascites in RS. The aim of this study was to investigate the incidence and etiology of chylous ascites after RS.

METHODS

This retrospective study included 291 patients with rectal cancer who underwent RS (n = 165) or LS (n = 126) with high ligation of the inferior mesenteric artery (IMA). Propensity score matching (PSM) was performed to compare the two groups.

RESULTS

\Dissection around the IMA was achieved using ultrasonic coagulating shears in most LS cases, and monopolar scissors in most RS cases, sometimes using bipolar vessel sealing device or bipolar forceps. The incidence of chylous ascites was 12.2% in RS and 4.1% in LS after PSM (P = .037). When limited to the RS group, multivariate analysis identified absence of lymphatic sealing at the left side of the IMA and shorter operative time as independent risk factors for chylous ascites. Except for duration of drain placement, no outcomes differed significantly with or without chylous ascites. One patient with chylous ascites developed later infection and required antibiotic treatment.

CONCLUSION

The incidence of chylous ascites is significantly higher in RS than in LS, and RS with incomplete lymphatic sealing around the IMA is a risk factor for chylous ascites in rectal cancer. Although outcomes for patients with chylous ascites were acceptable, adequate lymphatic sealing during dissection around the IMA is crucial to prevent chylous ascites in RS.

Influence of Robotic Rectal Resection Versus Laparoscopic Rectal Resection on Postoperative Ileus: A Single-center Experience

AIM

This study was performed to clarify the relationship between robotic rectal resection and postoperative ileus (POI) by comparing robotic surgery with laparoscopic surgery.

MATERIALS AND METHODS

We retrospectively reviewed 238 patients who underwent robotic (n=41) or laparoscopic (n=197) rectal resection for rectal cancer in our institution from January 2013 to June 2020. First, we compared the background factors and short-term surgical outcomes between robotic and laparoscopic surgery. Next, we investigated the postoperative complications of robotic and laparoscopic rectal resection. Finally, we identified the risk factors for POI following rectal cancer resection.

RESULTS

The percentages of patients with an Rb tumor location, treatment by abdominoperitoneal resection/intersphincteric resection/low anterior resection, a temporary diverting ileostomy, and a long operation time were significantly higher in robotic than laparoscopic surgery (P<0.0001,P=0.0002,P=0.0078, andP=0.0001, respectively). There was no significant difference in any individual postoperative complication between robotic and laparoscopic surgery. Risk factors for POI were male sex (P=0.0078), neoadjuvant chemoradiotherapy (P=0.0007), an Rb tumor location (P=0.0005), treatment by abdominoperitoneal resection/intersphincteric resection/low anterior resection (P=0.0044), a temporary diverting ileostomy (P<0.0001), and operation time of ≥240 minutes (P=0.0024). Notably, robotic surgery was not a risk factor for POI following rectal resection relative to laparoscopic surgery.

CONCLUSION

Although patients who underwent robotic surgery had more risk factors for POI, the risk of POI was similar between robotic and laparoscopic rectal resection.

A Case of Robotic Posterior Rectopexy for Full-thickness Rectal Prolapse

We describe our experience with robotic posterior rectopexy for a patient with full-thickness rectal prolapse. To our knowledge, this is the first report of such a case in the literature. A 94-year-old woman presented with a history of gradually worsening rectal prolapse. On examination, we found that the rectum was completely prolapsed, and we observed a prolapsed intestinal tract. Surgery was indicated and robotic rectopexy was performed without intraoperative complications. The postoperative course was uneventful, and she was discharged 10 days after the operation. One year later, there were no signs of recurrence. Robotic surgery has become common in recent years. We used robotic surgery for rectopexy, including the suturing procedure. Suturing in robotic surgery is easier than that in laparoscopic surgery, and we demonstrated that robotic rectopexy could be safely and easily performed. The trial was registered in the UMIN clinical trial registry (number 000040378).

The double bipolar method for robotic total mesorectal excision in patients with rectal cancer

Although meta-analyses and systematic reviews have clarified the benefits of robotic surgery, few studies have focused on robotic rectal surgery (RRS) and the use of Endowrist® instruments. Therefore, we evaluated RRS using the double bipolar method (DBM) and compared its short-term outcomes with those of RRS using the single bipolar method (SBM). This study enrolled 157 consecutive patients and all procedures were performed by the same surgeon and recorded through short video clips. We analyzed the patient demographics and short-term clinical outcomes. Although this observational study has several limitations, the console time for total mesorectal excision using the DBM was significantly shorter than that using the SBM. Although the DBM did not demonstrate a specific learning curve, it was a safe and feasible procedure even for patients with advanced disease. Further studies are needed to evaluate the cost-effectiveness of the DBM.

Learning curve for robotic bedside assistance for rectal cancer: application of the cumulative sum method

BACKGROUND

This investigation assesses the learning curve for dedicated bedside assistance at a facility that recently adopted robot-assisted rectal resection.

METHODS

Data from patients with rectal cancer who underwent robotic rectal resections from September 2019 through April 2020 were retrospectively analyzed. Before starting robotic surgery, we set the rule that a console surgeon would not enter the sterile field and all of those maneuvers would be left to a dedicated physician. Docking time was analyzed using the cumulative sum (CUSUM) method to evaluate the learning curve. Different phases in the learning curve were identified according to CUSUM plot configuration. A comparison was made of phases 1 and 2 combined, and phase 3.

RESULT

The procedures were performed in 30 patients. Median docking time, console time was 13 min. A total of nine patients had histories of abdominal surgery. CUSUM analysis of docking time demonstrated 3 phases. Each docking time was longer in Phase 1 (the first 3 cases) than the average docking time over the all cases. The docking time in Phase 2 (the 9 middle cases) approximated the average time over the all cases. Phase 3 (the remaining 18 cases) showed further improvement of the docking procedure and time was reduced. A comparison of Phases 1 and 2 combined, and Phase 3, revealed that Phase 3 had a significantly higher rate of history of abdominal surgery.

CONCLUSION

Docking manipulation proficiency was achieved in approximately 10 cases without the influence of surgical difficulty.

Robotic versus laparoscopic colorectal surgery in elderly patients in terms of recovery time: a monocentric experience

Colorectal cancer has a great socio-sanitary relevance. It represents the third cancer by incidence and mortality. Ageing plays a major role in the development of colorectal cancer and this tumour, in patients aged 65 and older, has gradually increased over the past decade. The robotic technique is considered the evolution of conventional laparoscopy. Few studies evaluate the effects of robotic surgery in elderly patient, and even fewer are those that compare it with laparoscopic surgery in this population. The aim of this study was to evaluate the perioperative outcomes of robotic colorectal surgery compared to laparoscopic colorectal surgery in patients older than 65 years. We conducted a retrospective study enrolling 83 elderly patients (age > 65) undergoing robotic and laparoscopic colectomy (32 and 51, respectively) between January 2019 and January 2021. For statistical analysis, p values were calculated using t test and chi-square test. p < 0.05 is the criterion for statistical significance. Statistical analyses were performed with the Number Cruncher Statistical System (NCSS) 2020 data analysis version 20.0.1 (Utah, USA). The operation time was higher in robotic left (p = 0.003, mean time 249.6 vs 211.7 min) and right (p = 0.004, mean time 238.5 vs 183.5 min) hemicolectomy and similar for procedures on rectosigmoid and rectum when compared to laparoscopic technique. In terms of length of hospital stay and recovery of bowel function, these values were significantly lower for robotic group in left hemicolectomy (p = 0.004), rectum (p = 0.003) and rectosigmoid (p = 0.003), while right hemicolectomy was similar in two groups (p = 0.26). There was no statistically significant difference between the groups regarding conversion rate, postoperative complications, length of specimen, number of lymph nodes encountered and oncological results. Colorectal robotic surgery in elderly patients appears as a feasible and safe surgical approach when compared to the laparoscopic one, showing a shorter recovery and a reduction of length of stay with similar oncological outcomes even if with an increase of operating times.

Update on Robotic Total Mesorectal Excision for Rectal Cancer

The minimally invasive treatment of rectal cancer with Total Mesorectal Excision is a complex and challenging procedure due to technical and anatomical issues which could impair postoperative, oncological and functional outcomes, especially in a defined subgroup of patients. The results from recent randomized controlled trials comparing laparoscopic versus open surgery are still conflicting and trans-anal bottom-up approaches have recently been developed. Robotic surgery represents the latest consistent innovation in the field of minimally invasive surgery that may potentially overcome the technical limitations of conventional laparoscopy thanks to an enhanced dexterity, especially in deep narrow operative fields such as the pelvis. Results from population-based multicenter studies have shown the potential advantages of robotic surgery when compared to its laparoscopic counterpart in terms of reduced conversions, complication rates and length of stay. Costs, often advocated as one of the main drawbacks of robotic surgery, should be thoroughly evaluated including both the direct and indirect costs, with the latter having the potential of counterbalancing the excess of expenditure directly related to the purchase and maintenance of robotic equipment. Further prospectively maintained or randomized data are still required to better delineate the advantages of the robotic platform, especially in the subset of most complex and technically challenging patients from both an anatomical and oncological standpoint.

Short-term outcome in robotic vs laparoscopic and open rectal tumor surgery within an ERAS protocol: a retrospective cohort study from the Swedish ERAS database

BACKGROUND

Advantages of robotic technique over laparoscopic technique in rectal tumor surgery have yet to be proven. Large multicenter, register-based cohort studies within an optimized perioperative care protocol are lacking. The aim of this retrospective cohort study was to compare short-term outcomes in robotic, laparoscopic and open rectal tumor resections, while also determining compliance to the enhanced recovery after surgery (ERAS)®Society Guidelines.

METHODS

All patients scheduled for rectal tumor resection and consecutively recorded in the Swedish part of the international ERAS® Interactive Audit System between January 1, 2010 to February 27, 2020, were included (N = 3125). Primary outcomes were postoperative complications and length of stay (LOS) and secondary outcomes compliance to the ERAS protocol, conversion to open surgery, symptoms delaying discharge and reoperations. Uni- and multivariate comparisons were used.

RESULTS

Robotic surgery (N = 827) had a similar rate of postoperative complications (Clavien-Dindo grades 1-5), 35.9% compared to open surgery (N = 1429) 40.9% (OR 1.15, 95% CI (0.93, 1.41)) and laparoscopic surgery (N = 869) 31.2% (OR 0.88, 95% CI (0.71, 1.08)). LOS was longer in the open group, median 9 days (IRR 1.35, 95% CI (1.27, 1.44)) and laparoscopic group, 7 days (IRR 1.14, 95% CI (1.07, 1.21)) compared to the robotic group, 6 days. Pre- and intraoperative compliance to the ERAS protocol were similar between groups.

CONCLUSIONS

In this multicenter cohort study, robotic surgery was associated with shorter LOS compared to both laparoscopic and open surgery and had lower conversion rates vs laparoscopic surgery. The rate of complications was similar between groups.

A meta-analysis of DaVinci Si versus Xi in colorectal surgery

BACKGROUND

The aim of this meta-analysis was to evaluate whether adoption of DaVinci Xi^® had any impact upon intra- and postoperative metrics in colorectal surgery.

METHODS

The Pubmed, CINAHL, Cochrane Library and MEDLINE (Ovid) databases were systematically searched. Operating time as well as docking and surgeon console times were the primary endpoints. Conversion and postoperative complication rates were the secondary endpoints.

RESULTS

Six studies totaling 610 patients (320 Si and 290 Xi) were included. Total operating time [MD (95% CI) = 30.553 (15.071, 46.035); p < 0.001], docking time [MD (95% CI) = 4.178 (2.120, 6.235); p < 0.001] and surgeon console time [MD (95% CI) = 17.246 (-0.479, 34.971); p = 0.056] were longer in DaVinci Si^® as compared to DaVinci Xi^® . No significant difference was found in conversion (p = 0.816) and postoperative complication rates (p = 0.405).

CONCLUSION

This meta-analysis found that the adoption of DaVinci Xi^® was associated with significantly decreased total operating time as well as docking and surgeon console times. Conversion and complication rates were similar.

Comparison of the perioperative outcomes of laparoscopic surgery, robotic surgery, open surgery, and transanal total mesorectal excision for rectal cancer: An overview of systematic reviews

Regarding the surgical approaches for rectal cancer, many techniques have been reported in randomized controlled trials, meta-analyses, and reviews of comparisons between two techniques, e.g. open surgery vs laparoscopic surgery, laparoscopic surgery vs robotic surgery, or laparoscopic surgery vs transanal total mesorectal excision. Since robotic surgery and transanal total mesorectal excision were developed after laparoscopic surgery had become an established minimally invasive technique, they have each been compared with laparoscopic surgery. Therefore, a review was performed to compare the surgical outcomes of robotic surgery and transanal total mesorectal excision, and to perform such comparisons among ≥3 of the above mentioned approaches, in the expectation that this review will serve as a reference for aiding treatment selection in future. The results of the current review suggest that all of the examined procedures have advantages and disadvantages, but that there are no decisive factors that could be used to select one procedure over any other. At the present time it cannot be demonstrated that laparoscopic surgery, robotic surgery, transanal total mesorectal excision, or open surgery is superior to the other techniques, and it is important to select the best technique for each patient from among those that a surgeon can perform. It is also important to maintain a flexible attitude that allows new techniques to be adopted as needed in the future.