Endoscopic laser treatment for rectosigmoid villous adenoma: factors affecting the results

Impact of margin ablation after EMR of large nonpedunculated colonic polyps in routine clinical practice

BACKGROUND AND AIMS

Owing to its simplicity, effectiveness, and safety, EMR is the preferred treatment for the majority of large (≥20 mm) nonpedunculated colonic polyps (LNPCPs); however, residual and recurrent adenomas (RRAs) encountered during surveillance constitute a major limitation. Thermal ablation of the post-EMR mucosal defect margin has been shown to be highly efficacious in reducing RRA in a randomized trial setting, but data on effectiveness in clinical practice are scarce. We aimed to determine the effectiveness of this technique for reducing RRAs in routine clinical practice.

METHODS

We analyzed data collected in 3 hospitals in Israel: Prospective data were available in 2 hospitals where margin thermal ablation with snare-tip soft coagulation (STSC) is routinely performed after EMR of LNPCP (TA-EMR). Only retrospective data were available from the third center, which exclusively did not perform STSC (standard EMR] [S-EMR]), during the study period. Surveillance was performed 4 to 6 months after resection. RRA was assessed endoscopically with high-definition white light and optical chromoendoscopy. The primary endpoint was RRA at first surveillance colonoscopy.

RESULTS

Data from 764 patients with 824 LNPCPs were analyzed. The patient and lesion characteristics were similar between the groups. Four hundred sixty-four LNPCPs were treated by TA-EMR and 360 LNPCPs by S-EMR. RRA at first surveillance colonoscopy was detected in 14 (3.6%) of lesions in the TA-EMR group compared with 96 (31.6%) in the S-EMR group (P < .001; RR = .14; 95% CI, .07-.29). Adverse events were comparable between the 2 groups.

CONCLUSION

TA-EMR leads to a significant reduction in post-EMR recurrence in routine clinical practice.

Prophylactic Snare Tip Soft Coagulation and Its Impact on Adenoma Recurrence After Colonic Endoscopic Mucosal Resection

BACKGROUND

Up to 20% of patients can have recurrence of adenomatous tissue at first surveillance study after colon endoscopic mucosal resection of large polyps.

AIMS

To determine whether an educational intervention discussing thermal ablation of lateral margins of the mucosectomy site of post-endoscopic mucosal resection defect with snare tip soft coagulation (STSC) would decrease adenoma recurrence.

METHODS

We performed a single-center quality improvement project from November 1, 2016, to November 30, 2017. Gastroenterologists underwent an educational intervention demonstrating the treatment of peripheral margins of mucosectomy site with STSC after standard mucosectomy technique. These cases (intervention group) were compared with consecutive procedures performed prior to commencement of the quality improvement study (pre-intervention group). Patients with large colorectal lesions (≥ 20 mm) were included.

RESULTS

Of the 120 patients here included, overall demographics of the groups were similar and the most common histology was sessile serrated adenoma (study group 45% vs 32% control group). Adenoma recurrence on intervention group and pre-intervention group was 12% versus 30%; p = 0.01. On univariate analysis, biopsy prior to mucosectomy, intraprocedural bleeding, and application of STSC on mucosectomy defect were the strongest predictors of adenoma recurrence. Adenoma recurrence in the intervention group was significantly lower than in the pre-intervention group in both univariate (odds ratio, 0.3 [95% CI, 0.11-0.80]) and multivariate analyses (odds ratio, 0.2 [95% CI, 0.12-0.92]).

CONCLUSIONS

The implementation of STSC of post-endoscopic mucosal resection peripheral defects is clinically feasible and significantly decreased adenoma recurrence.

Colorectal endoscopic mucosal resection (EMR)

Colonoscopy has the benefit of detecting and treating precancerous adenomatous polyps and thus reduces mortality associated with CRC. Screening colonoscopy is the keystone for prevention of colorectal cancer. Over the last 20 years there has been increased in the management of large colorectal polyps from surgery to endoscopic removal techniques which is less invasive. Traditionally surgical resection was the treatment of choice for many years for larger polyps but colectomy poses significant morbidity of 14-46% and mortality of up to 7%. There are several advantages of endoscopic resection technique over surgery; it is less invasive, less expensive, has rapid recovery, and preserves the normal gut functions. In addition patient satisfaction and efficacy of EMR is higher with minor complications. Thus, this has facilitated the development of advanced resection technique for the treatment of large colorectal polyps called as endoscopic mucosal resection (EMR).

Endoscopic snare resection followed by laser ablation in the treatment of large, sessile rectal adenomas

BACKGROUND AND AIMS

Large sessile rectal adenomas can be difficult to eradicate, and different treatment modalities are available. The aim of this study was to evaluate outcome after endoscopic snare resection followed by Nd:YAG laser ablation.

MATERIAL AND METHODS

Over a 10-year period 92 of 99 (93%) patients were registered prospectively and attended follow-up examinations with endoscopy and biopsies.

RESULTS

Fifty-four (59%) men and 38 (41%) women were included; 67 patients (73%) had high grade (severe) intraepithelial dysplasia or intramucosal neoplasia. The adenomas ranged from 2-9 cm (median 4 cm) in diameter, and were located 2-15 cm (median 5 cm) from the anal verge. A median of two (range 1-6) piecemeal snare resection sessions and a median of one (range 1-7) laser treatments were performed for each patient. Complete eradication was achieved in 86 patients (93%). Over a median follow-up period of 26 months, 20/86 (23%) suffered local recurrence, eight of whom were given a second laser treatment without developing further recurrence. In five of eight frail patients considered unsuitable for more radical treatment, repeated laser treatment was effective in keeping the adenoma small and symptoms at a minimum. As a whole the treatment was successful in 74/92 (80%) and partially successful in 5/92 (5%) of the patients.

CONCLUSIONS

Snare resection followed by laser ablation is safe and still has a place in the treatment of old, frail patients with large rectal adenomas. However, there is a risk of missing an infiltrating carcinoma, and other treatment options are preferable in fit patients.

Endoscopic Nd:YAG laser therapy for villous adenomas of the right colon

BACKGROUND

Endoscopic laser therapy is considered an acceptable treatment of benign colorectal adenomas. The aim of our study was to evaluate the efficacy of Nd:YAG laser to ablate right-sided colonic sessile adenomas.

METHODS

Between January 1990 and February 1996, 56 patients underwent laser therapy because of high operative risk or refusal of surgery. Lesions were located as follows: cecum (23), ascending, (15), and hepatic flexure (18). Six patients (10.7%) had multiple polyps in the ascending colon. Histologic examination showed a tubulovillous pattern in 20 (35.7%) and a villous pattern in 36 (64.3%). Low-grade dysplasia was detected in 44 patients (78. 5%) and high-grade dysplasia in 12 (21.4%).

RESULTS

The number of laser sessions ranged between 1 and 6 (median 3) and complete ablation, histologically confirmed, was achieved in 49 cases (87.5%). Seven patients (12.5%) underwent surgery: 2 for incomplete tumor destruction, 3 because of invasive carcinoma on repeated biopsies. Two patients (3.6%) had complications (one perforation of the cecum and one hemorrhage). Follow-up ranged from 6 to 60 months and no recurrences were observed.

CONCLUSION

Laser therapy is an effective method for the destruction of sessile adenomas of the right colon in selected patients.

Local excision of rectal tumours

Local excision of colorectal tumour may be palliative or curative. Recent advances in minimal access techniques have allowed curative excision to be offered to a wider range of patients. Absolute indications for potentially curative local excision include mobile tumours, T1 tumours (assessed by ultrasonography), well or moderately differentiated histology (determined by biopsy) and tumour size less than 3 cm. Relative indications include T2 and T3 tumours (by ultrasonography), poorly differentiated histology (by biopsy) and tumour size greater than 3 cm depending on patient fitness. The rationale for these recommendations is described in detail.

Lasers in rectosigmoid tumors

Over a 14-year period, 746 patients were treated at the Lille Laser Center for rectosigmoid tumor. Two hundred seventy-two patients were treated for palliation of symptoms from rectosigmoid cancer and 474 patients were treated for a benign rectosigmoid villous adenoma. The immediate success rate and complication rate were 85% and 2%, respectively, for patients with advanced cancer, and 92.8% and 1.8% for those with a villous adenoma. Patients with an advanced cancer remained functionally improved during a 10.1-month average period after initial improvement. The recurrence rate after initial treatment for villous adenomas was 18% during a 29.7-month average follow-up. Immediate results were influenced by reason for treatment, initial symptoms, and circumferential extension for patients with a cancer, and only by circumferential extension for patients with a villous adenoma. Long-term results were influenced by reason for treatment and circumferential extension for patients with cancer, and by reason for treatment, initial histology and localization for patients with a villous adenoma. Laser treatment provided relief of symptoms in inoperable patients with advanced rectosigmoid carcinomas. Because treatment is long and difficult and the cancer rate is high, endoscopic laser should be limited in patients with a circumferential villous adenoma to non-surgical candidates. The risk of complication after surgery (some being fatal) has to be balanced against the risk of undetected carcinoma and the indication for endoscopic laser treatment should be discussed case by case.

Endoscopic treatment of sessile rectal adenomas: comparison of Nd:YAG laser therapy and injection-assisted piecemeal polypectomy

This prospective study was carried out in order to compare endoscopic laser therapy with injection-assisted piecemeal polypectomy for treatment of sessile rectal adenomas. We randomized 94 patients with rectal sessile adenomas to either of the two treatments. The adenomas were classified according to size as extensive or intermediate. Of the patients with extensive adenomas, a complete ablation was achieved in 63.6% with laser versus 33.3% with piecemeal snaring (p < .01). For the intermediate adenomas, the rates of permanent ablation were 81.2% with laser versus 86.6% with piecemeal snaring polypectomy (difference not statistically significant). The complication rates were acceptable in both the laser and piecemeal snaring groups. (One case of perforation and one case of stenosis were observed in the laser group, both probably related to prior electroresection.) Our study suggests that the specific indication for laser therapy should be extensive lesions; with intermediate adenomas, laser therapy and injection-assisted piecemeal polypectomy are equally efficacious for achieving complete ablation. However, the duration of initial treatment differs: 6.3 weeks for laser therapy versus 2.4 weeks for piecemeal polypectomy; moreover, about 70% of the intermediate adenomas were eradicated with a single session of piecemeal polypectomy.

Lasers in anorectal surgery

Laser technology has been applied widely in the treatment of hemorrhoids, condylomas, and anorectal neoplasms. It is claimed by its proponents to result in less pain, improved healing, and more rapid recovery as compared with conventional surgery. Laser therapy, however, is expensive and potentially dangerous, and advantages generally have not been substantiated by controlled clinical trials. The possible benefits and potential risks of laser treatment of anorectal disorders are examined.

Therapeutic colonoscopy

Therapeutic colonoscopy has replaced or lessened to a significant degree the need or extent of traditional open surgical procedures. The common uses of therapeutic colonoscopy are hemostasis, resection and ablation of benign and malignant disease, decompression and recanalization of obstructed or dilated bowel, as well as foreign body extraction. Bleeding from arteriovenous and other vascular abnormalities can be controlled with 40% to 80% success rates using endoscopically delivered, monopolar, bipolar, or laser coagulation. The palliation of bleeding recurrent or inoperable colorectal cancer is achieved in up to 90% of patients. Virtually all pedunculated adenomas and most sessile adenomas are regularly removed colonoscopically, while large and recurrent villous adenomas in high risk individuals can be successfully managed by endoscopically delivered laser ablation techniques. Emergency colonoscopic reduction of sigmoid volvulus is performed pre-operatively and decompression of the dilated colon of non-obstructive colonic ileus is now regularly achieved. Colonic strictures have been dilated with a variety of techniques ranging from divulsion with through-the-scope balloon dilators to laser recanalization. Pre-operative endoscopic laser relief of tumor obstruction is employed to avoid preliminary or decompressing colostomy. Endoscopic laser debulking and recanalization of recurrent or inoperable cancer has been achieved with up to 80% success and various foreign bodies may be extracted from the colon with a number of endoscopic techniques. The morbidity of therapeutic colonoscopy has ranged from 1% to 2% for polypectomy to 11% for laser palliation of bleeding from advanced cancer, often with obstruction.

Poor palliation of colorectal malignancy with the neodymium yttrium-aluminium-garnet laser

The neodymium yttrium-aluminium-garnet (NdYAG) laser was used to palliate the symptoms of 38 patients with rectal carcinoma unsuitable for radical surgery. All patients with small tumours (n = 6) reported resolution of their symptoms. In contrast, those with large tumours frequently showed little improvement (n = 18) and alternative surgical management was necessary in 12 patients. The overall early mortality rate (less than 1 month after first treatment) was 21 per cent. The NdYAG laser offers good palliation and may even cure small colorectal tumours in patients who are unsuitable for surgery. For large circumferential tumours, those associated with obstruction and those close to or involving the anal sphincters, however, the results are poor and better symptom control may be achieved by other means.

Conservative surgery for early cancer of the distal rectum

From 1967 through 1988, 36 patients underwent local excision of a distal rectal cancer as an initial operative procedure with curative intent. A diagnostic, preoperative protocol was performed to assess the histologic grade of the tumor, the depth of penetration in the rectal wall, and the presence of positive lymph nodes or distant metastases. All patients had a transanal local excision performed under general anesthesia. If preoperative criteria were not confirmed by histopathologic specimen examination, a major operation was advised. To increase the chance of local control, external adjuvant radiotherapy was used in T2 cancers. Postoperative mortality was 0 percent. The postoperative complication rate was 9.3 percent. The observed local recurrence rate was 3 percent, and the rectal cancer-specific death rate was 6 percent. We compared these results with those obtained in 70 concomitant patients operated on by us employing a traditional resection for Dukes' A rectal cancer. There are no statistically significant differences between groups. In light of our findings, a policy of curative local excision is justified in accurately selected cases of distal rectal cancer.

Endoscopic laser therapy for neoplastic lesions of the colorectum

Surgical resection is the therapy of choice for most colorectal neoplasms. Endoscopic laser therapy (ELT) is a recently developed alternative for treatment of colorectal neoplasms and is applicable in a variety of clinical circumstances in which nonoperative treatment is preferable. The experience with ELT using the Nd:YAG (neodynium:yttrium-aluminum-garnet) laser in 42 patients was analyzed. The diagnosis was colorectal adenocarcinoma in 32 patients (76%) and neoplastic polyps in 10 (24%). ELT was undertaken either as a palliative treatment for malignant disease (60%), with curative intent for benign disease (26%), or as a temporizing measure (14%) in a total of 84 treatment sessions. Successful palliation or cure was achieved in 40 patients (95%) with 4 minor complications (9%) and no procedure-related deaths. This experience confirms ELT as an effective alternative to surgical therapy in the palliative, curative, or interim treatment of certain colorectal neoplasms in patients with prohibitive operative risk, limited anticipated survival, incurability, or diffidence toward operation.

Lasers in surgery

In January 1991 the winter meeting of the Surgical Research Society was held at St. Bartholomew's Hospital and the Institute of Education, London. During the meeting a symposium was held entitled 'Shedding light on lasers'. Speakers addressed the general principles of lasers, laser-tissue interactions and the applications of lasers in gastro-enterology and in vascular disease. This was followed by an open discussion of the current indications, complications and outcome, together with future possible applications for lasers in medicine.

Nd:YAG laser therapy for colorectal polyps

Adenomatous polyps are the precursors of most colonic cancers and should be removed and recovered for histological analysis. Removal by endoscopic laser photocoagulation offers a safe alternative to surgery. We report our experience of managing selected colonic polyps by neodymium:yttrium aluminum garnet (Nd:YAG) laser.

Endoscopic treatment by snare electrocoagulation prior to Nd:YAG laser photocoagulation in 85 voluminous colorectal villous adenomas

The association of endoscopic resection with Nd:YAG laser photocoagulation was used to treat benign colorectal villous adenomas. Eight-five patients were included: 49 with surgical contraindications, 35 for whom surgical resection appeared to be too hazardous, and 1 who refused surgery. Forty-five tumors had an axial extension between 1 and 3 cm, and 40 tumors had an axial extension of at least 4 cm. Diathermic snare resection was performed to remove large tumoral fragments prior to laser photocoagulation of the residual flat lesions. Treatments were repeated every 15 days until total tumor destruction was achieved. A carcinoma was detected in biopsy specimens obtained during endoscopic treatment of five patients. Two patients were lost to follow-up. Treatment results could be analyzed in 78 patients. Successful treatment was achieved in 67 patients. Tumor destruction was complete in 77 percent of patients who had lesions of at least 4 cm diameter and in 93 percent of patients with smaller lesions. The axial extension of the tumor was the main factor affecting the results of treatment. No major complications occurred. During the average 103-week follow-up period, 21 percent of the patients with total tumor destruction had a recurrence. The risk of recurrence was correlated with the number of initial treatment sessions and previous surgery treatment. It would appear that the treatment with endoscopic resection prior to Nd:YAG laser photocoagulation is a safe and effective method in the destruction of colorectal villous adenomas.

Palliative laser therapy for tumours of the gastrointestinal tract

The argon ion and Nd: YAG lasers were used initially in the mid 1970s to produce haemostasis in acutely bleeding peptic ulcers. With the evolution of treatment techniques, the main area of use of the Nd: YAG laser has now become the palliation of upper and lower GI malignancies. Thermal ablation of tumours may be achieved endoscopically by non-contact laser application at high power, or in the contact mode using artificial sapphire probes at much lower energy levels. Still lower powers can be employed therapeutically using interstitial hyperthermia, and this is best applied endoscopically to exophytic tumour nodules in the gut lumen or to tumours localized ultrasonically in solid organs, such as the liver or pancreas. PDT involves destruction of previously photosensitized tumours by the cytotoxic action of singlet oxygen released on exposure of the neoplastic tissue to light of an appropriate wavelength. Although the theory is attractive, the available experimental and clinical information suggests that treatment should, for the present, be confined to small or early malignancies whose depth of invasion can be verified by endoscopic ultrasound or other imaging techniques. PDT carries the biological advantage of healing by regeneration with preservation of connective tissue stroma, while the Nd: YAG laser causes destruction by thermal coagulation or vaporization and subsequent healing by fibrosis. Laser therapy of GI tumours expands the range of therapeutic endoscopic procedures in a relatively safe and readily repeatable manner which achieves high patient tolerance. By reducing morbidity, mortality and time spent in hospital, it offers significant advantages in the palliative treatment of conditions previously managed by conventional surgery, and also offers opportunities for treatment of previously inoperable disorders. Developments in laser technology and diagnostic imaging techniques are likely to promote laser therapy in the future as a primary treatment modality.

The future of veterinary endoscopy

The developing areas of video endoscopy, endoscopic ultrasonography, and small-bowel endoscopy are discussed in this article, and new endoscopic approaches to strictures and bleeding lesions of the gastrointestinal tract are presented. The potential applications of these techniques in veterinary medicine are left to the imagination of the reader.

Endorectal sonography in the management of rectal villous tumours

Thirty-seven patients with rectal villous tumours were investigated by endorectal sonography to assess the integrity of the rectal muscularis propria at the tumour level. In four cases assessment of invasion was impossible. In 24 patients, endosonography revealed an ultrasonically superficial lesion not infiltrating the muscular layer. This was confirmed either, in the case of laser treatment, by the absence of malignant recurrence during the follow-up period or by histological examination after surgical resection. In nine patients, endosonography showed infiltration of the muscular layer. This was histologically confirmed in five operated patients. In the remaining four, laser destruction was performed: in two, a rectal adenocarcinoma was present 3 and 6 months later, respectively. These findings show that endosonography has a place in the management of rectal villous tumours, demonstrating invasive cancer in cases where other forms of assessment were wrongly reassuring.

Gastrointestinal laser endoscopy--future horizons

The laser, especially the neodymium:yttrium-aluminum-garnet device, has been a dominant influence on the development of gastrointestinal therapeutic endoscopy. More than 2,000 such procedures were performed in the first 5 years of experience with laser endoscopy at the Mayo Clinic. The major areas for future development are (1) the control of acute and chronic gastrointestinal bleeding, (2) the palliation of malignant gastrointestinal neoplasms, and (3) the management of benign and malignant obstructive lesions of the biliary tract. Refinements in laser devices, delivery systems, and techniques such as photodynamic therapy will be needed to achieve more selective tissue destruction. Improvements in the new adjunctive endoscopic methods of electronic (video) endoscopy and ultrasonography may enhance evolving laser applications by more accurately identifying diseased tissues and guiding their destruction.

Endoscopic laser applications in the gastrointestinal tract

The Nd:YAG and, to a lesser degree, the argon laser have become valuable tools for the surgical endoscopist. Over the last 10 years, the impetus for application of these expensive instruments has changed from what the laser can do to what the laser can do better than less expensive technology. Whereas a few controlled randomized studies suggest that the Nd:YAG laser is better than no therapy and equivalent to other heat-producing instruments for control of upper gastrointestinal bleeding, such studies do not exist for other laser applications. Despite the lack of such studies, we remain convinced that, where available, lasers are the instrument of choice for palliation of unresectable mucosal-based cancers, coagulation of arteriovenous malformations, and ablation of certain adenomatous polyps in selected patients. New techniques on the horizon include the use of endoscopic photo-dynamic therapy for treatment of gastrointestinal cancers and endoscopic laser fragmentation of large common bile duct stones. The potential role for a nonthermal "endoscopic scalpel" is questionable because most gastrointestinal tissues are well vascularized; however, a pulsed laser capable of cutting and coagulation, such as the holmium:YAG laser, may be of some value for incisional endoscopic procedures.