Clinical use of a front lifting hood rectoscope tube for transanal endoscopic microsurgery

Development of a new operating rectal tube with a side window for transanal endoscopic surgery

The authors describe a new rectal tube for use in transanal endoscopic surgery. The tube is a transparent plastic sheath with its forward end closed, measuring 40 mm in diameter and 150 mm in insert length. It has a window, measuring 40 mm in diameter, on its side. The target lesion, captured within the side window, prolapses into the rectal tube and is excellently visualised without positive pressure gas insufflation. This paper gives details of the tube and reports on a sessile rectal tumour successfully treated using the new system.

Transanal endoscopic operation: a new proposal

PURPOSE

The transanal procedure for rectal cancer surgery is one of the many techniques currently available. Different techniques for local excision of rectal tumors include: conventional transanal technique, posterior access surgery, therapeutic colonoscopy, transanal endoscopic surgery.

METHODS

The aim of the present study is to describe a new method of transanal endoscopic resection, transanal endoscopic operation (TEO), and performed with the aid of a surgical proctoscope especially designed for this purpose and report the results obtained in 32 patients submitted to the TEO and to compare these results with those obtained with other techniques currently available. The average proportions of recurrence, post-operation complications and posterior resections were analyzed by means of a metanalysis. Data on the distance and size of rectal lesions, the operative timing and hospitalization time were distributed in graphs according to authors and techniques.

RESULTS

The results were favorable and equivalent to those described in the literature.

CONCLUSIONS

The surgical proctoscope specially designed for this study is efficient and has a low cost; the TEO is easily performed with the aid of this equipment; the final results were favorable and similar to those obtained with other available techniques for endoscopic transanal intestinal resection, which are of high cost and less availability.

A new proctoscope for transanal endoscopic operations

Transanal access is one of many currently used procedures for rectal cancer treatment. The techniques used for local excision include conventional transanal excision, posterior access, therapeutic colonoscopy and transanal endoscopic approaches. The aim of the present study was to present a new surgical proctoscope for the endoscopic transanal excision of rectal lesions. A cylindrical proctoscope with a diameter of 4 cm was devised and built. The end inserted into the anus has a bevelled aspect and rounded borders, allowing correct exposure of the anal lesion. The rectoscope is fixed to the anal border with surgical thread through perforations in the external end. A base screw holds a fibre-light which illuminates the operative field. Part of the equipment is a guide which is positioned inside the rectoscope on insertion into the anus. In operations utilizing this proctoscope, 17 adenomas, 25 adenocarcinomas, 1 carcinoid and 1 endometrioma were excised. The diameter of the lesions varied from 1 to 6 cm. The range of procedures that are possible with this new proctoscope are similar to those achieved with conventional techniques which, however, require more expensive equipment. Hence, the present study demonstrates that this newly devised low-cost proctoscope is an efficient tool for the transanal endoscopic excision of rectal lesions.

Development of a shape memory alloy actuator for transanal endoscopic microsurgery

This paper describes problems in traditional transanal endoscopic microsurgery (TEM), and proposes a mechatronics approach in new design. As one of several actuation mechanisms to expose rectal cavity, a compression coil spring made of shape memory alloy (SMA) has been studied. A custom SMA spring actuator was designed to displace 12 mm with 45 N driving force. This actuator was embedded with our new TEM tubular structure and can be used to expose a rectal site up to 60 mm wide and 80 mm long. This exposure is considered to be sufficient for treating many tumors.

Transanal endoscopic microsurgery: a systematic review

PURPOSE

The aim of this study was to systematically review the evidence relating to the safety and efficacy of transanal endoscopic microsurgery, a relatively new technique used to locally excise rectal tumors, compared with existing techniques such as anterior resections and abdominoperineal resections or local excisions.

METHODS

We conducted a systematic review of comparative studies and case series of transanal endoscopic microsurgery from 1980 to August 2002.

RESULTS

Three comparative studies (including one randomized, controlled trial) and 55 case series were included. The first area of study was the safety and efficacy of adenomas. In the randomized, controlled trial, no difference could be detected in the rate of early complications between transanal endoscopic microsurgery (10.3 percent) and direct local excision (17 percent) (relative risk, 0.61; 95 percent confidence interval, 0.29-1.29). Transanal endoscopic microsurgery resulted in less local recurrence (6/98; 6 percent) than direct local excision (20/90; 22 percent) (relative risk, 0.28; 95 percent confidence interval, 0.12-0.66). The 6 percent rate of local recurrence for transanal endoscopic microsurgery in this trial is consistent with the rates found in case series of transanal endoscopic microsurgery (median, 5 percent). The second area of study was the safety and efficacy of carcinomas. In the randomized, controlled trial, no difference could be detected in the rate of complications between transanal endoscopic microsurgery and direct local excision (relative risk for overall early complication rates, 0.56; 95 percent confidence interval, 0.22-1.42). No differences in survival or local recurrence rate between transanal endoscopic microsurgery and anterior resection could be detected in either the randomized, controlled trial (hazard ratio,1.02 for survival) or the nonrandomized, comparative study. There were 2 of 25 (8 percent) transanal endoscopic microsurgery recurrences in the randomized, controlled trial, but no figures were given for recurrence after anterior resection. In the case series, the median local recurrence rate for transanal endoscopic microsurgery was 8.4 percent, ranging from 0 percent to 50 percent. The third comparison was cost of the procedures. Transanal endoscopic microsurgery had both a lower recurrence rate and a lower cost than local excision or anterior resection for adenomas. Although the effectiveness of transanal endoscopic microsurgery could not be established for carcinomas, costs were lower than those for either anterior resection or abdominoperineal resection.

CONCLUSIONS

The evidence regarding transanal endoscopic microsurgery is very limited, being largely based on a single relatively small randomized, controlled trial. However, transanal endoscopic microsurgery does appear to result in fewer recurrences than those with direct local excision in adenomas and thus may be a useful procedure for several small niches of patient types--e.g., for large benign lesions of the middle to upper third of the rectum, for T1 low-risk rectal cancers, and for palliative, not curative, use in more advanced tumors.

Gasless, video endoscopic transanal excision for carcinoid and laterally spreading tumors of the rectum

BACKGROUND

The aim of this study is to determine whether gasless, video endoscopic transanal-rectal tumor excision (gasless VTEM) is a valid treatment for rectal carcinoid and laterally spreading tumors (LST).

METHODS

Eighty-four patients with an adenoma, adenocarcinoma (Tis/T1), or carcinoid tumor of the rectum were divided into three groups: (i) LST ( n = 17 patients), (ii) carcinoid ( n = 11), and (iii) control with other types of tumors ( n = 56).

RESULTS

The LST group had a longer median operating time than in the control group, whereas the carcinoid group had a shorter operating time. Two patients (11.7%) in LST group developed peritoneal entry during the operation, while 2 patients (3.6%) in the control group experienced postoperative complications. During a median follow-up length of 55.2 months, one patient in the LST group developed a recurrence.

CONCLUSIONS

Gasless VTEM is a simple, minimally invasive procedure used to treat LST and carcinoid tumors of the rectum. However, resection for the LST group had a high risk of peritoneal entry during operation.

Surgical technique and outcome of gasless video endoscopic transanal rectal tumour excision

BACKGROUND

Transanal endoscopic microsurgery (TEM) is unpopular because of its high cost and most surgeons' unfamiliarity with microscopic surgery. This report describes an experience with a modification of TEM, gasless video endoscopic transanal rectal tumour excision (gasless VTEM), which incorporates a standard laparoscopic video camera and requires no carbon dioxide insufflation system.

METHODS

One hundred and one patients with 105 rectal tumours underwent gasless VTEM between 1993 and 2000.

RESULTS

Histological examination revealed 18 adenomas, 75 carcinomas (Tis, 47; T1, 23; T2, five), 11 carcinoid tumours and one lymphoma. The median height above the dentate line and maximum tumour diameter was 5.0 (range 2-14) cm and 2.0 (range 0.4-8.0) cm respectively. The peritoneal cavity was opened intraoperatively in two patients. The median operating time was 53 (range 15-202) min. Bleeding, suture dehiscence and transient incontinence developed after operation in four patients. There was no operative death. Median hospital stay was 5 (range 1-21) days. Eleven patients with T1/T2 staging underwent subsequent radical resection. The median duration of follow-up was 52.3 months. One patient with a carcinoma developed a recurrence.

CONCLUSION

Gasless VTEM is a feasible, safe and minimally invasive procedure for the treatment of selected rectal adenomas and early carcinomas. The suggested modifications may make the procedure more widely available.