Envisioning the future of colorectal surgery: preclinical assessment and detailed description of an endoluminal robotic system (ColubrisMX ELS).

BACKGROUND: The EndoLuminal Surgical System (ELS) is an emerging non-linear robotic system specifically designed for transanal surgery that allows for excision of colorectal neoplasia and luminal defect closure. METHODS: An evaluation of ELS was conducted by a single surgeon in a preclinical setting at the EndoSurgical Center of Florida in Orlando, between October 1st, 2020 and December 31st, 2020, using porcine colon as a model. Mock lesions measured 2.5 to 3.5 cm were excised partial-thickness. Specimen quality and excision time was assessed and evaluated. RESULTS: Twenty consecutive robotic transanal minimally invasive surgery (TAMIS) operations utilizing the ELS system were successfully performed without fragmentation. The mean and standard deviation procedure time for all 20 cases was 18.41 ± 14.15 min. The latter 10 cases were completed in substantially less time, suggesting that ELS requires at least 10 preclinical cases for a surgeon to become familiar with the technology. A second task, namely suture closure of the partial-thickness defect, was performed in 9 of the 20 cases. Mean time and standard deviation for this task measured 27.89 ± 10.07 min. There were no adverse events. CONCLUSIONS: ELS was successful in performing the tasks of partial-thickness disc excision and closure in a preclinical evaluation. Further study is necessary to determine its clinical applicability.

Robotic-assisted stereotactic real-time navigation: initial clinical experience and feasibility for rectal cancer surgery.

BACKGROUND: Real-time stereotactic navigation for transanal total mesorectal excision has been demonstrated to be feasible in small pilot series using laparoscopic techniques. The possibility of real-time stereotactic navigation coupled with robotics has not been previously explored in a clinical setting. METHODS: After pre-clinical assessment, and configuration of a robotic-assisted navigational system, two patients with locally advanced rectal cancer were selected for enrollment into a pilot study designed to assess the feasibility of navigation coupled with the robotic da Vinci Xi platform via TilePro interface. In one case, fluorescence-guided surgery was also used as an adjunct for structure localization, with local administration of indocyanine green into the ureters and at the tumor site. RESULTS: Each operation was successfully completed with a robotic-assisted approach; image-guided navigation provided computed accuracy of ± 4.5 to 4.6 mm. The principle limitation encountered was navigation signal dropout due to temporary loss of direct line-of-sight with the navigational system's infrared camera. Subjectively, the aid of navigation assisted the operating surgeon in identifying critical anatomical planes. The combination of fluorescence with image-guided surgery further augmented the surgeon's perception of the operative field. CONCLUSIONS: The combination of stereotactic navigation and robotic surgery is feasible, although some limitations and technical challenges were observed. For complex surgery, the addition of navigation to robotics can improve surgical precision. This will likely represent the next step in the evolution of robotics and in the development of digital surgery.

Direct target NOTES: prospective applications for next generation robotic platforms.

BACKGROUND: A new era in surgical robotics has centered on alternative access to anatomic targets and next generation designs include flexible, single-port systems which follow circuitous rather than straight pathways. Such systems maintain a small footprint and could be utilized for specialized operations based on direct organ target natural orifice transluminal endoscopic surgery (NOTES), of which transanal total mesorectal excision (taTME) is an important derivative. METHODS: During two sessions, four direct target NOTES operations were conducted on a cadaveric model using a flexible robotic system to demonstrate proof-of-concept of the application of a next generation robotic system to specific types of NOTES operations, all of which required removal of a direct target organ through natural orifice access. These four operations were (a) robotic taTME, (b) robotic transvaginal hysterectomy in conjunction with (c) robotic transvaginal salpingo-oophorectomy, and in an ex vivo model, (d) trans-cecal appendectomy. RESULTS: Feasibility was demonstrated in all cases using the Flex® Robotic System with Colorectal Drive. During taTME, the platform excursion was 17 cm along a non-linear path; operative time was 57 min for the transanal portion of the dissection. Robotic transvaginal hysterectomy was successfully completed in 78 min with transvaginal extraction of the uterus, although laparoscopic assistance was required. Robotic transvaginal unilateral salpingo-oophorectomy with transvaginal extraction of the ovary and fallopian tube was performed without laparoscopic assistance in 13.5 min. In an ex vivo model, a robotic trans-cecal appendectomy was also successfully performed for the purpose of demonstrating proof-of-concept only; this was completed in 24 min. CONCLUSIONS: A flexible robotic system has the potential to access anatomy along circuitous paths, making it a suitable platform for direct target NOTES. The conceptual operations posed could be considered suitable for next generation robotics once the technology is optimized, and after further preclinical validation.

Transanal hemorrhoidal dearterialization (THD): a safe procedure for the anticoagulated patient?

BACKGROUND: Approximately one in five persons living in the USA is maintained on oral anticoagulation. It has typically been recommended that anticoagulation be withheld prior to hemorrhoidal procedures. Transanal hemorrhoidal dearterialization (THD) is a minimally invasive treatment for symptomatic hemorrhoids, and outcomes with patients on anticoagulation who have undergone this procedure have not been previously reported. Here, we report our preliminary results of patients who underwent THD while on anticoagulation. METHODS: During a 53-month period (February 2009-July 2015), patients with symptomatic hemorrhoids refractory to medical management who underwent surgical treatment with THD were retrospectively reviewed. The subset of patients who underwent THD while anticoagulated was compared to a cohort of patient who were not taking anticoagulation and who otherwise demonstrated normal coagulation profiles and who did not have a known predisposition to bleeding or inherited coagulopathy. The primary study endpoint was to assess postoperative bleeding in patients who were maintained on anticoagulation before and after surgery. RESULTS: During the 53-month study period, 106 patients underwent the THD procedure for symptomatic hemorrhoids. Of these, seventy patients underwent THD without anticoagulation therapy, while 36 patients underwent THD while taking one or more oral anticoagulants. The postoperative morbidity between the two cohorts was similar, and specifically there was no statistical difference in the rate of postoperative hemorrhage (19.4 vs. 15.7 %; odds ratio 1.295, 95 % CI 0.455-3.688, p = 0.785). No patient, in either cohort, required re-intervention for any reason during the study period. Patients who underwent THD while on anticoagulation were less likely to have recurrent hemorrhoidal disease during the study's 6-month median follow-up period (2.8 vs. 7.1 %, p = 0.049). CONCLUSIONS: These preliminary data reveal that THD can be performed on anticoagulated patients without cessation of oral agents without increasing morbidity from postoperative bleeding.

Transanal total mesorectal excision for rectal cancer: early outcomes in 50 consecutive patients.

AIM: Minimally invasive approaches to proctectomy for rectal cancer have not been widely adopted due to inherent technical challenges. A modification of traditional transabdominal mobilization, termed transanal total mesorectal excision (TaTME), has the potential to improve access to the distal rectum. The aim of the current study is to assess outcomes following TaTME for rectal cancer. METHOD: This is a retrospective analysis of a prospectively maintained database of consecutive patients who underwent TaTME for rectal cancer at a single institution. The study period was from 1 March 2012 to 31 July 2015. RESULTS: During the study period 50 patients underwent TaTME. The median tumour distance from the anal verge was 4.4 (3.0-5.5) cm. The rate of conversion from a planned minimally invasive approach was 2.2%. The median operative time was 267.0 (227.0-331.0) min. The median lymph node yield was 18.0 (12.0-23.8), the macroscopic quality assessment of the resected specimen was incomplete in 2% and the circumferential resection margin positivity rate was 4%. Intra-operative morbidity occurred in 6% and the 30 day morbidity rate was 36%. The median length of stay was 4.5 (4.0-8.0) days. The median follow-up was 15.1 (7.0-23.2) months; two patients have developed a local recurrence and eight patients have developed distant recurrence. CONCLUSION: These data suggest that TaTME for rectal cancer is feasible with an acceptable pathological outcome and morbidity profile. Further data on functional and long-term survival outcomes are required.

Robotic TransAnal Minimally Invasive Surgery in a cadaveric model.

The technique of TransAnal Minimally Invasive Surgery (TAMIS) was pioneered in 2009 as a hybrid approach to endoluminal resections of appropriately selected rectal lesions. There are, however, limitations to performing this type of resection. Robotic TAMIS is a novel, experimental technique and in this study was performed in a cadaveric model at a surgical education center. Various tasks were carried out using robotic TAMIS, including full-thickness sharp and cautery excision of rectal wall, as well as intra-luminal suturing of the surgical defect. It was found that for the da Vinci-trained surgeon, these tasks were simple to perform and accomplished with greater precision when compared to standard TAMIS. Our initial results indicate that robotic TAMIS overcomes the limitations of standard TAMIS and that it is a feasible platform for transanal surgery. The cost, however, of performing robotic TAMIS may limit its application to special cases in which standard TAMIS or transanal endoscopic microsurgery resections may prove difficult. Further study is necessary to validate these preliminary findings before robotic TAMIS is performed on live patients.

Time-related decay of the benefits of biofeedback therapy.

Although immediate results are good to excellent in great majority of patients who undergo biofeedback treatment (BFT) for chronic constipation and fecal incontinence, they tend to loose the benefit over a period of time. The purpose of this study was to evaluate the long-term sustainability of results after successful biofeedback treatment. Two groups of patients who successfully completed BFT at our institution from 1995 to 1997 were created based on the date of completion. The first had a mean follow-up of 35 months and the second group was followed for an average of 12 months. Both groups were questioned as to the presence of constipation and incontinence. The questioning was focused depending on the patient's diagnosis. This information was then compared with the initial BFT results. Overall, all patients were satisfied by the initial BFT results. All patients initially had an excellent or good response to BFT. However, after a mean of 35 months, in the first group, 19 of 22 patients had a near complete regression back to their pre-biofeedback status. In the 14 patients in the second group with mean follow-up of 12 months, 11 had a significant decay in benefits. Only time was a significant factor in the decay of BFT benefits. In conclusion, BFT is highly effective in the treatment of selected patients with complex defecation disorders. Although there is a high initial success rate, there is a clear loss of the immediate benefits over time. Other factors such as dietary habits, pelvic floor exercises, manometry, invasive EMG, and rectal sensation did not correlate with long-term outcomes. The comparison between the two groups reveals a linear model describing the time decay of the benefits of BFT. Based on the linear model, patients may need reevaluation after one year and may benefit from additional BFT.

Clinical, manometric, and EMG characteristics of patients with fecal incontinence.

Fecal incontinence occurs frequently in both men and women. Yet, few studies on fecal incontinence have separated the evaluation and interpretation of data by gender. This study was designed to identify differences in the clinical, anorectal manometry, and electromyography (EMG) characteristics between male and female patients with fecal incontinence. We compared 53 incontinent males (mean age, 64 years) with 72 incontinent females (mean age, 61 years). Each patient underwent computerized anorectal manometry, and invasive (pudendal nerve conduction studies and concentric needle EMG) and noninvasive EMG (anal sensor surface electrode). An anal incontinence score (AIS) ranging from 0 to 6 was used to categorize patients. Male patients had higher incontinence scores at presentation (AIS greater than 4, 70% vs. 54%). Female patients had significantly lower resting pressure (40 vs. 53 mmHg, p < 0.05) and more women had sphincter asymmetry (36% vs. 25%, p < 0.05). Both groups had similar PNTMLs (2.41 vs. 2.47 ms). Difference was seen in the net strength of the sphincter (women 4.0 microV vs. men 8.0 microV, p < 0.05), as measured by noninvasive EMG. In conclusion, it is well known that there are differences in anorectal physiologic function between male and female patients with normal continence. Comparing male and female patients with fecal incontinence suggests that female patients tend to have worse sphincter function that men. Both groups had similar EMG alterations, suggesting a common neurogenic injury as etiology. Future studies are needed to address the sexes separately.

Complications of laparoscopic surgery for rectal cancer: avoidance and management.

Since laparoscopy was first introduced as a diagnostic tool for pelvic pathology 15 years ago, the technique has been successfully adapted by general and specialty surgeons as a therapeutic tool for a variety of diseases. Laparoscopic surgery has been used to treat colon and rectal pathology since 1991. The introduction and acceptance of this new access technique also brought the realization of specific complications associated with a laparoscopic approach. Advanced laparoscopic skills are required for laparoscopic pelvic and, to minimize laparoscopic-associated complications, specialized training is required. We will review the specific complications of the laparoscopic approach in pelvic surgery with a view to their recognition, prevention, and treatment.

Small-cell carcinoma of the rectum: report of two cases.

Small-cell carcinoma of the rectum is an infrequent pathologic finding, and its precise incidence is unknown. Its incidence is less than 0.2 percent among all colorectal cancers. This tumor manifests highly aggressive behavior. The treatment of choice is combination chemotherapy similar to that used for small-cell carcinoma of the lung, but in small localized tumors surgery plus chemotherapy is an alternative. We present two cases of small-cell carcinoma of the lower rectum and a review of the literature.

Electromyographic assessment of biofeedback training for fecal incontinence and chronic constipation.

INTRODUCTION: Biofeedback training is an effective modality for the treatment of chronic constipation and fecal incontinence. In general, patients express satisfaction and perceive functional improvement following biofeedback therapy; however, quantifying these observations has been difficult. AIM: This study was undertaken to evaluate the physiologic benefits of biofeedback therapy as reflected by noninvasive electromyography parameters. METHODS: Fifty-five patients who underwent computerized electromyography-based biofeedback treatment at our institution between July 1993 and July 1995 were identified. Noninvasive electromyographic testing was performed before, during (weekly), and at completion of training. Mean number of weekly sessions was seven (range, 5-11). Short-term and ten-second contractions (amplitude/microV), sustained contractions (endurance, in seconds), and net strength (microV) of the external anal sphincter before and after biofeedback were compared for differences. RESULTS: There were 30 patients with chronic constipation, mean age, 65.3 (range, 33-86) years, composed of 24 women, and 25 patients with fecal incontinence, mean age 66 (range, 34-85) years, composed of 12 males. Statistically significant improvement in endurance and net strength following biofeedback training was noted in both the constipated and the fecal incontinence groups. Fifty-three of 55 (96.4 percent) patients expressed 50 to 100 percent subjective satisfaction after biofeedback therapy. Forty-six of 55 (83.6 percent) patients demonstrated individually improved endurance. CONCLUSIONS: Sphincter endurance and net strength, as measured by noninvasive electromyography, significantly improve following biofeedback therapy in both constipated and fecal incontinence patients. These data suggest that endurance and net strength may be useful tools in assessing a benefit from biofeedback training in these patients.

Biofeedback in colorectal practice: a multicenter, statewide, three-year experience.

PURPOSE: Biofeedback treatment is often offered to patients in colorectal centers; however, standards of treatment are still lacking. A dedicated team approach is desirable but difficult to coordinate. We present our three-year experience of electromyographic-based biofeedback treatment offered within a multicenter, statewide organization. METHODS: Between October 1992 and October 1995, 188 patients completed a biofeedback treatment program in one of five coordinated centers within a 200-mile radius. A unified common database was established and continuously updated. A colorectal surgeon served as statewide director, and dedicated teams were established at each location. Each local team included the medical director and a certified biofeedback therapist and had access to a dietitian and a nurse data coordinator. Electromyographic-based biofeedback sessions were given weekly, and a home trainer program was established. RESULTS: A total of 116 patients with chronic constipation had a mean of eight (range, 2-14) weekly sessions. A total of 72 patients with fecal incontinence had a mean of seven (range, 2-11) weekly sessions. A total of 84 percent of the constipated and 85 percent of the incontinent patients had significant improvement with biofeedback treatment. Patient compliance and satisfaction were high. Constipated patients increased the mean number of weekly unassisted bowel movements from 0.8 to 6.5. Incontinent patients decreased the mean number of weekly gross incontinence episodes from 11.8 to 2. CONCLUSIONS: Biofeedback treatment can be extremely successful in both incontinent and constipated patients. A large geographic area can be covered with coordinated centers in which each dedicated team uses a unified treatment protocol, and a common database is established.

Complications of laparoscopic colorectal surgery. Analysis and comparison of early vs. latter experience.

PURPOSE: The aim of this study was to test if the techniques learned during our early learning experience have proved to be effective in reducing the complications specifically related to the laparoscopic technique of colorectal surgery. METHODS: From October 1991 until July 1996, 195 laparoscopic operations were performed on the colon and the rectum. These data were divided into "early" and "latter" groups. The conversion reasons and early and late postoperative complications were analyzed and compared. RESULTS: Incidence of conversions required because of iatrogenic injuries showed a decline from 7.3 percent in the early group to 1.4 percent in the latter group. Sixty-six postoperative complications were observed in 59 (30.3 percent) patients. Complications specifically related to the technique of laparoscopic surgery occurred in nine (4.6 percent) patients. These were postoperative bleeding in three patients, port site hernias in five patients, and left ureteric stricture in one patient. Eight (6.5 percent) of these complications occurred in the early group, whereas one (1.4 percent) occurred in the latter group. Analyzing the conversions caused by intraoperative iatrogenic injuries and the specific postoperative complications together reveals that the incidence of 13.8 percent (17/123) in the early group has been reduced significantly to 2.8 percent (2/72) in the latter group. CONCLUSIONS: On the basis of our experience, we have identified techniques, which are discussed in detail, to make laparoscopic colorectal surgery safe. Strict adherence to these techniques has significantly reduced the incidence of complications, specifically those related to the laparoscopic technique.

Effective peritoneal and fascial closure of abdominal trocar sites utilizing the Endo-Judge.

With the increasing frequency of minimally invasive surgical procedures, we have begun to see descriptions of new and unforseen complications. One such complication is the formation of a ventral hernia through an unclosed or poorly closed fascial defect created by trocar insertion. The necessity to perform fascial closure of trocar insertion sites, particularly those greater than 5 mm, has been established and is routinely practiced by the majority of laparoscopists. Standard suture techniques can be difficult and frustrating, and often involve blind closure of the fascial defect. A number of instruments have been developed to facilitate this fascial closure. We are currently using a self-contained disposable fascial closure device (Endo-JudgeTM--Synergistic Medical Technologies, Inc., Orlando, Florida), which is quick and relatively simple to use. It enables secure fascial closure under direct vision with the pneumoperitoneum intact. Initial results reveal consistent fascial and peritoneal closure and no postoperative hernia formation.

Laparoscopic resections for colorectal carcinoma. A three-year experience.

UNLABELLED: Laparoscopic resection for carcinoma of the colon and rectum is currently under intense scrutiny. PURPOSE: The purpose of this study is to review our three-year experience of laparoscopic surgery for colon and rectal carcinoma. METHODS: From October 1991 to September 1994, 76 laparoscopic procedures were performed for colorectal neoplasia (32 males and 44 females; mean age, 69 years). Fifty-five procedures were done for carcinoma, 16 for large polyps, and five for diversion in patients with unresectable cancer. For resectable tumors, the average size was 4 cm; staging was as follows: Dukes A, 10 patients; Dukes B1, 11; Dukes B2, 18; Dukes C1, 1; Dukes C2, 9; and Dukes D, 8. Fourteen cases (25 percent) that were converted to open procedures were compared with the 41 cases that were completed laparoscopically for differences in tumor size, surgical margins, number of lymph nodes harvested, length of hospital stay, and evidence of recurrence. Procedures completed laparoscopically were then compared with a group of open controls completed during the same time period. RESULTS: During the first six months, the conversion rate was 32 percent but dropped to 8 percent in the last six months. There were a total of 19 complications (25 percent), of which 8 (14 percent) were directly related to the laparoscopic technique. The mean number of lymph nodes harvested in laparoscopic resection for carcinoma was 8.5, and the average closest tumor margin was 4.5 cm. When laparoscopic resections were compared with converted and standard open colectomies, there was no significant difference in tumor margins or numbers of nodes resected. Length of stay was significantly shorter for anterior resections completed laparoscopically than for converted or conventional colectomies. Although this was also the trend for right hemicolectomies, it did not reach statistical significance. Mean follow-up of the group completed laparoscopically was 16.7 months, during which there was one recurrence. There were no trocar site recurrences. CONCLUSIONS: This early experience seems to indicate that laparoscopic surgery for colorectal carcinoma does not per se compromise surgical oncologic principles and encourages us to continue our critical appraisal of this technique.

Endorectal ultrasound of T3 and T4 rectal cancers after preoperative chemoradiation.

PURPOSE: This study was undertaken to assess the accuracy and ability of endorectal ultrasound (ERUS) to predict changes in rectal tumor stage after a preoperative chemoradiation protocol. METHODS: Since December 1990, all rectal malignancies at our institution have been preoperatively staged with ERUS. ERUS has been an essential tool in preoperative staging of rectal cancer patients, possessing an overall accuracy of 84 percent for T stage and 81 percent for lymph node status in our hands (Williamson PR, unpublished data). Beginning in July 1992, all patients staged with T3 or T4 lesions on initial ERUS have been entered into a protocol consisting of preoperative chemoradiation therapy (CRT). This protocol consists of patients receiving 4,500 to 5,040 rads for five to eight weeks and concomitantly receiving sensitizing doses of 5-fluorouracil and/or leucovorin. All patients were scheduled for sphincter-saving or abdomino-perineal resections six to eight weeks following completion of CRT. A repeat ERUS was performed on each patient one week before surgery. RESULTS: The study group consisted of 15 patients who completed CRT, including 12 males and 3 females. Evidence of tumor shrinkage via ERUS measurement was seen in all patients. Average tumor shrinkage as assessed by ERUS was 16 percent by width and 32 percent by depth of invasion. Sonographic level of invasion and nodal status were each downstaged in 38 percent of patients. Pathologic evaluation comparison revealed that the level of invasion was downstaged in 47 percent and nodal status in 88 percent compared with initial ERUS staging. Of those patients downstaged, 4 of 11 (36 percent) revealed no tumor in the pathology specimen. CONCLUSIONS: We conclude from our early experience that although ERUS offers a method for assessing degree of shrinkage and downstaging of T3 and T4 lesions after CRT, presently it does not closely predict the pathologic results. Results are strongly related to the experience of the ultrasonographer. The ability to distinguish tumor from radiation-induced changes to perirectal tissues is under continued investigation, and a new method of interpreting the data obtained by ERUS after CRT will need to be established.