Transanal endoscopic microsurgery (TEM) resection of rectal tumors

Efficacy and safety of transanal endoscopic microsurgery for early rectal cancer: a meta-analysis

Background

The gold standard for the treatment of rectal cancer is radical surgery with total mesorectal excision (TME). As one of the alternatives to radical surgery, local resection has been proposed for the treatment of early rectal cancer. The purpose of this article was to evaluate the safety and efficacy of transanal endoscopic microsurgery (TEM) in the treatment of early rectal cancer.

Methods

By searching the PubMed, Cochrane Library, Web of Science, and China National Knowledge Infrastructure databases, we selected all articles on TEM for early rectal cancer. Two researchers independently completed the entire process from screening, inclusion to data extraction and performed statistical analysis using RevMan 5.3. The primary outcomes included basic patient characteristics, overall survival rate, disease-free survival rate, disease-specific survival rate, recurrence rate, and complication rate and type.

Results

A total of 33 articles were included in this meta-analysis. The results showed that the overall survival rate was 100% for T0 stage, 98.1% for Tis (carcinoma in situ) stage, and 80.2% for early stage rectal cancer patients (83.9% for T1 and 72.4% for T2). The weighted overall survival rate was 94% (RD = 0.94, 95% CI = 0.93-0.95, I 2 = 80%, P < 0.00001) for all stage patients, the weighted disease-free survival rate was 91% (RD = 0.91, 95% CI = 0.90-0.93, I 2 = 83%, P < 0.00001), and the disease-specific survival rate was 97% (RD = 0.97, 95% CI = 0.96-0.98, I 2 = 63%, P < 0.00001). The recurrence rate was 0.5% for T0 stage, 1.9% for Tis stage, and 11.9% for early stage rectal cancer patients (8.1% for T1 and 19.7% for T2). The weighted recurrence rate was 7% (RD = 0.07, 95% CI = 0.06-0.08, I 2 = 69%, P < 0.00001) for all stage patients. The weighted complications rate was 11% (RD = 0.11, 95% CI = 0.10-0.12, I 2 = 66%, P < 0.00001) for all stage patients, with Clavien-Dindo grade I accounting for 77.7%, Clavien-Dindo grade II accounting for 8%, and Clavien-Dindo grade III accounting for 14.3%.

Conclusion

The results showed that TEM has a high postoperative survival rate, low recurrence rate, and low complication rate in the T0 stage, Tis stage, and T1 stage, indicating its good safety and efficacy. For the treatment of T2 stage, TEM has a lower overall survival rate and a higher recurrence rate. Our meta-analysis results suggest that TEM alone is not recommended as a curative treatment for T2 stage; on the contrary, TME is more frequently recommended.

A natural orifice transrectal approach for oncologic resection of the rectosigmoid: an experimental study and comparison with conventional laparoscopy

BACKGROUND

A transrectal (TR) approach for natural orifice translumenal endoscopic surgery (NOTES) makes sense for colorectal surgery because the colotomy can be incorporated into subsequent anastomosis. Because cancer is a primary indication for left-sided colon resection, oncologic standards will have to be met by a NOTES procedure. This study aimed to assess whether pure TR rectosigmoidectomy can be performed with strict adherence to oncologic principles compared with a conventional laparoscopically assisted approach (LAP).

METHODS

Human male cadavers were allocated to either TR (n = 4) or LAP (n = 2). A simulated sigmoid lesion was created at 25 cm. Transrectal retrograde mobilization of the rectosigmoid was performed using conventional transanal endoscopic microsurgery (TEM) instrumentation. After ligation of the superior hemorrhoidal artery and further mobilization, the specimen was delivered transanally and divided extracorporeally. Using a circular stapler, NOTES colorectal anastomosis was performed. Lymph node yield, adequate resection margins, and operative time were compared with LAP.

RESULTS

Transrectal retrograde rectosigmoid dissection was achieved in all attempts (4/4) and showed numbers of lymph nodes (median, 5; range, 3-6) similar to the LAP group (median, 4.5; range, 2-7). One pure TR approach failed to resect the lesion. Three TR procedures required additional mobilization via an abdominal approach to provide adequate margins. The mean length of TR specimens was 16 ± 4 cm compared with 31 ± 9 cm achieved by LAP (p < 0.01). The TR operative time was significantly longer (247 ± 15 vs 110 ± 14 min).

CONCLUSION

Lymph node yield during TR rectosigmoidectomy was similar to that achieved by the LAP approach. However, conventional TEM instrumentation alone did not permit adequate colon mobilization. This indicates a need for flexible instrumentation or other technical solutions to perform true NOTES colectomies.

Advances in cancer surgery: natural orifice surgery (NOTES) for oncological diseases

Natural orifice transluminal endoscopic surgery (NOTES) is a new concept that attempts to reduce the impact of surgery on the patient. In surgical oncology several studies have already revealed that a minimally invasive approach provides at least the same, if not a better, long-term outcome. One could hypothesize that a less invasive approach such as NOTES could further enhance such advantages. Since its initial description, NOTES has become clinical reality and today nearly every organ is accessible by a transluminal approach, in at least the experimental setting. Subsequent to published research, first clinical studies on NOTES in oncology were reported and the accuracy of transgastric peritoneoscopy for staging of pancreas cancer was shown to be similar to laparoscopy in humans. A NOTES gastro-jejunostomy via transgastric access has also been proposed to decrease invasiveness of palliative treatment of duodenal, biliary and pancreatic cancers. Colorectal cancer resection via transanal access would offer a clear-cut patient advantage over laparoscopic and would not be subject to the frequent criticism of violating an innocent second organ, as the colon or rectum is always breached in a colectomy. Natural orifice endoluminal therapies, such as endoscopic submucosal dissection, already have been clinically applied for several years. Improved techniques or instruments evolving from NOTES technology might enhance its widespread use for the treatment of early malignancies and thereby again will provide a tremendous benefit for the patient. Although still somewhat controversial, the subject of natural orifice surgery in oncological disease indicates that current laboratory efforts to introduce NOTES into cancer surgery could be ready for cautious clinical investigations. The final determination of patient benefit will need well-constructed prospective study.

Transanal endoscopic operation for rectal lesions using two-dimensional visualization and standard endoscopic instruments: a prospective cohort study and comparison with the literature

BACKGROUND

The transanal endoscopic operation (TEO) has proved to be an effective alternative to conventional surgery for the treatment of rectal lesions. The TEO procedure offers reduced morbidity, faster recovery and equivalent oncologic outcome. Currently, two instrument sets are available: one with three-dimensional (Wolf) and one with two-dimensional (Storz) optic capacities. The three-dimensional (3D) instrument set is considered the golden standard. Although the advantages of TEO are imposing, the procedure with the 3D armamentarium has certain technical and financial drawbacks. This study therefore aimed to compare results for the TEO 2D alternative with recently published results for 3D TEO.

METHODS

All consecutive patients with benign or malignant pT1 or pT2 rectal lesions undergoing TEO were prospectively followed. All procedures were performed with the 2D armamentarium using standard endoscopic instruments, a rectoscope (diameter, 4 cm; working length, 7.5-15 cm), and 5-mm Ligasure and Ultracision. Operating times, complications, hospital stay, and oncologic outcome were gathered and compared with published data.

RESULTS

Between 2004 and 2006, 31 patients with a median age of 75 years (range, 33-87 years) underwent 31 TEOs for a total of 36 rectal lesions (29 tubulovillous adenomas and 7 adenocarcinomas). The median distance of the lesion from the anal verge was 7.5 cm (range, 5-15 cm). The median lesion diameter was 2.3 cm (range, 0.5-5.0 cm). The locations of the lesions were as follows: 18 on the dorsal, 5 on the ventral, and 5 on the lateral rectal wall. The median operating time was 55 min (range, 25-165 min), compared with 105 min reported in the literature. All the lesions except one could be radically excised. No intraoperative complications occurred. Postoperative complications occurred for three patients, all due to hemorrhage. The median hospital stay was 3 days (range, 1-21 days). During a median follow-up period of 15 months (range, 1-35 months), two recurrences took place.

CONCLUSION

The study findings showed that for rectal tumors located up to 15 cm from the anal verge with a maximal diameter of 5 cm, TEO using standard laparoscopic instruments with a 2D view is feasible and provides results comparable with those associated with a 3D view and dedicated instruments. Furthermore, the 2D procedure can be performed with improved ergonomics due to movable monitors and is considerably less expensive.

Techniques for transanal access to the peritoneal cavity

Natural orifice translumenal endoscopic surgery (NOTES) represents a burgeoning but still largely experimental field. For surgeries involving the upper abdominal organs, the transanal approach promises to provide a more direct route in contrast to the often cumbersome retroflexion typically required with the transgastric approach. The potential disadvantages of the transanal route are also significant and include issues of sterility, the risk of inadvertent trauma to adjacent organs during transmural puncture, and the risk of colonic wall shearing. This article reviews the evolution of transanal access to the peritoneal cavity, highlights the various techniques that have been used for transanal access and closure, and discusses in further detail the relative advantages and disadvantages of this approach.