Endoscopic treatment of gastrointestinal tumors: indications and results of laser photocoagulation and photodynamic therapy

Endoscopic Treatment of Carpet-Like Adenomas of the Rectum

Background

Transanal microsurgery, endoscopic laser photocoagulation and snare resection have all been used to treat large sessile adenomas of the rectum alternatively to a surgical approach. However, such modalities are often defective due to the carpet-like shape and the frequently large extension of the lesions.

Methods

Ten patients with carpet-like adenoma were submitted to transanal endoscopic resection by urological resectoscope.

Results

Complete eradication was obtained in all lesions. The mean number of treatment sessions was 3 (range, 1-5). The mean time between the first treatment and the complete eradication was 6 months (range, 1-18). The only complications were an intraoperative and an early postoperative bleeding. There was no early or late mortality related to the procedure.

Conclusions

Transanal endoscopic resection by urological resectoscope appears to be a suitable therapeutic approach for sessile and carpet-like adenomas of the rectum or for pTI cancer in patients who refuse major surgery.

Ablative therapies for colorectal polyps and malignancy

Endoscopic techniques are gaining popularity in the management of colorectal polyps and occasionally superficial cancers. While their use is in many times palliative, they have proven to be curative in carefully selected patients with polyps or malignancies, with less morbidity than radical resection. However, one should note that data supporting local and ablative therapies for colorectal cancer is scarce and may be subject to publication bias. Therefore, for curative intent, these techniques should only be considered in highly select cases as higher rates of local recurrences have also been reported. The aim of this review is to explain the different modalities of local and ablative therapies specific to colorectal neoplasia and explain the indications and circumstances where they have been most successful.

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.

Photodynamic therapy of cancer: an update

Photodynamic therapy (PDT) is a clinically approved, minimally invasive therapeutic procedure that can exert a selective cytotoxic activity toward malignant cells. The procedure involves administration of a photosensitizing agent followed by irradiation at a wavelength corresponding to an absorbance band of the sensitizer. In the presence of oxygen, a series of events lead to direct tumor cell death, damage to the microvasculature, and induction of a local inflammatory reaction. Clinical studies revealed that PDT can be curative, particularly in early stage tumors. It can prolong survival in patients with inoperable cancers and significantly improve quality of life. Minimal normal tissue toxicity, negligible systemic effects, greatly reduced long-term morbidity, lack of intrinsic or acquired resistance mechanisms, and excellent cosmetic as well as organ function-sparing effects of this treatment make it a valuable therapeutic option for combination treatments. With a number of recent technological improvements, PDT has the potential to become integrated into the mainstream of cancer treatment.

Palliative endoscopic trans-anal resection of advanced rectosigmoid carcinoma

There is no consensus on optimal treatment of patients with rectosigmoid cancer and unresectable metastatic disease. This is a retrospective review of all patients who underwent palliative endoscopic trans-anal resection (ETAR) of rectosigmoid cancer over a 10-year period. Fourteen patients (11 male) with a mean age 69.7 years (range 51-86) underwent ETAR; 11 for rectal tumours and 3 for rectosigmoid tumours. Indications included tenesmus (5), troublesome bleeding (6), mucous discharge (1) and obstructed defaecation (8). The number of treatment episodes varied from 1 to 4 (median 1). The symptom-free interval was mean 6.25 months (range 2-15). Eight patients had lifelong relief of symptoms and four patients are currently symptom free. There were two short-term failures treated with stenting (1) and abdominoperineal resection (1). There were no immediate post-treatment complications. One patient developed increasing incontinence and another pelvic pain after ETAR attributable to local tumour infiltration. ETAR provides a convenient and safe method of palliation for patients with local symptoms of advanced rectosigmoid carcinoma.

Inflammation and carcinogenesis of the biliary tract: update on endoscopic treatment

Both diagnosis and treatment of cholangiocarcinoma are suboptimal. From the former standpoint, fluorescence in situ hybridization, direct cholangioscopy, endocystoscopy, and optical coherence tomography are just a few of the myriad technologies being studied or employed to improve diagnostic yield. From the latter standpoint, most series suggest that fewer than 1 third of patients are resectable for cure, although liver transplantation has increasingly been used in a subset of cholangiocarcinoma patients with extrahepatic disease. Palliation has included chemotherapy which is of dubious value in most series. Instead, a majority of therapies have addressed mechanisms to improve biliary drainage to delay and preclude hepatic failure and minimize the risk of cholangitis. Although the latter has been accomplished with surgery and attempted with external beam irradiation and brachytherapy, percutaneous and/or endoscopic drainage are the most commonly employed methods in widespread use. There are prospective, randomized studies that suggest that bilateral stenting is associated with improved outcomes in bifurcation lesions if plastic stents are placed, that percutaneous transhepatic biliary drainage is more successful than endoscopic stenting in Klatskin tumors, that self-expandable biliary stents have prolonged patency compared with plastic prostheses, and that, if approached with computed tomography and magnetic resonance imaging guidance to preclude contamination of the contralateral undrained system, outcomes are comparable in patients treated with unilateral as opposed to bilateral self-expandable metal stents. There is a single prospective, randomized study suggesting that patients treated with endoscopic or percutaneous stenting in conjunction with photodynamic therapy have prolonged survival compared with stent placement alone.

Operative colonoscopy in cancer patients

Gastrointestinal endoscopy has experienced tremendous developments in technology and equipment over the past decades. It is not only a diagnostic tool, but it also allows some interventional treatments in benign and malignant digestive diseases. Operative colonoscopy has been used to perform curative treatment of various kinds of polyps, flat and carpet-like adenomas and early colorectal carcinomas. Endoscopic palliative treatment strategies, such as the placement of self-expandable metal stents (SEMS), laser ablation, photodynamic therapy (PDT), argon plasma coagulation (APC), electrocoagulation, and injection therapy, have been proved to effectively alleviate advanced colorectal cancer (CRC) associated symptoms and maintain or improve the quality of the patient's remaining life.

Interventional management of malignant colorectal obstruction: use of covered and uncovered stents

Objective

We wanted to evaluate usefulness of uncovered stent in comparison with covered stent for the palliative treatment of malignant colorectal obstruction.

Materials and Methods

Covered (n = 52, type 1 and type 2) and uncovered (n = 22, type 3) stents were placed in 74 patients with malignant colorectal obstruction. Stent insertion was performed for palliative treatment in 37 patients (covered stent: n = 23 and uncovered stent: n = 14). In the palliative group, the data on the success of the procedure, the stent patency and the complications between the two groups (covered versus uncovered stents) were compared.

Results

The technical success rate was 89% (33/37). Symptomatic improvement was achieved in 86% (18/21) of the covered stent group and in 92% (11/12) of the uncovered stent group patients. The period of follow-up ranged from three to 319 days (mean period: 116±85 days). The mean period of stent patency was 157±33 days in the covered stent group and 165±25 days in the uncovered stent group. In the covered stent group, stent migration (n = 11), stent fracture (n = 2) and poor expansion of the stent (n = 2) were noted. In the uncovered stent group, tumor ingrowth into the stents (n = 3) was noted.

Conclusion

Self-expanding metallic stents are effective for relieving malignant colorectal obstruction. The rate of complications is lower in the uncovered stent group than in the covered stent group.

Uses of photodynamic therapy in premalignant and malignant lesions of the gastrointestinal tract beyond the esophagus

Much has recently been written regarding the use of photodynamic therapy for the treatment of esophageal carcinoma and dysplastic Barrett's esophagus. This review, however, describes the clinical experience using photodynamic therapy with various photosensitizer agents for the treatment of diseases in other areas of the gut, especially the pancreaticobiliary tract where European studies have established the role of porfimer sodium photodynamic therapy in the management of patients with cholangiocarcinoma.

Therapeutic endoscopic retrograde cholangiopancreatography: what the future holds

These are exciting times for interventional endoscopists performing ERCP. The advent of noninvasive, diagnostic techniques of the pancreaticobiliary tree has resulted in a shift toward more therapeutic procedures. The combination of major technologic advances together with endoscopists' growing comfort with invasive procedures has helped to push the boundaries of endoscopic therapy. These therapies, however, should always be sanctioned by sound science and well-controlled clinical trials.

Barrett's Esophagus: Ablative Endoscopic Techniques

Barrett's esophagus consists of a precancerous condition in which the progression from dysplasia to adenocarcinoma is now well documented. The management of patients affected by Barrett's esophagus is still debatable, in particular for the risk of surgical treatment in the presence of small precancerous lesions or early adenocarcinoma. Furthermore, quality of life after surgical resection is often poor. Endoscopy is the main diagnostic and follow-up procedure in Barrett's esophagus: it allows the detection and treatment of severe dysplasia and invasive esophageal adenocarcinoma. Endoscopic treatment also produces reduction or disappearance of intestinal metaplasia. In these cases, the aim of the treatment is to prevent dysplastic changes. Moreover, the ideal endoscopic treatment should be safe, easy to perform and cost effective. Thermal (electrocoagulation, laser, argon-plasma coagulation), photochemical (photodynamic therapy) or ablative (endoscopic mucosal resection) procedures have been proposed alone or in combination, with the aim to completely eradicate dysplastic lesions or early adenocarcinoma as an alternative to surgical treatment. Endoscopic removal of the lesions is followed by restoration of normal epithelium. Some questions about patient selection, prevention of recurrence and best endoscopic treatment still remain unanswered.

Photodynamic therapy and the alimentary tract

Photodynamic therapy offers the possibility of relatively selective tumour necrosis and normal tissue healing. It has many potential applications but as yet no clear role. Articles, editorials and case reports published primarily in English and listed in Medline/ISI up to April 2000 or identified by a manual search have been reviewed in an attempt to provide a comprehensive overview of the use of photodynamic therapy in the alimentary tract. It is concluded that photodynamic therapy can be an effective treatment for superficial pre-malignant mucosal lesions and early cancers, especially in diffuse disease. Suitable patients include those wishing to avoid surgery, high risk subjects or those in whom other forms of treatment have failed. Superiority over other methods of ablation has not so far been demonstrated. Cheaper and more effective photosensitizers and improved techniques of light delivery are likely to increase the application of photodynamic therapy.

Endoscopic application of photodynamic therapy for cholangiocarcinoma

BACKGROUND

Previous studies indicate that photodynamic therapy provides effective relief from biliary obstruction in advanced cholangiocarcinoma. This report describes a method of applying photodynamic therapy in the biliary tract by using accessories available in the United States.

METHODS

Endoscopic retrograde cholangiography was performed to define the proximal and distal extent of intraductal tumor. Patients were injected with 2 mg/kg of sodium porfimer. Forty-eight hours later a commercially available cylindrical diffusing laser fiber was inserted into an 8F biliary catheter equipped with a 0.038 inch side-hole at its distal tip. After positioning of a 0.035 inch guidewire proximal to the biliary stricture, the preloaded catheter was advanced over the guidewire by using the monorail technique. Laser light was applied at a power of 400 mW/cm fiber for a total energy of 180 J/cm.(2)

RESULTS

Fourteen treatments were performed on 6 patients with tumors of Bismuth types IV (n = 2), III (n = 3), or II (n = 1). By using the preloaded biliary catheter, adequate positioning of the laser fiber was achieved in all patients. A fracture of the diffuser tip occurred during 1 of the treatments. Two patients developed acute cholangitis and 2 patients experienced skin phototoxicity.

CONCLUSIONS

Photodynamic therapy for cholangiocarcinoma is safe and technically feasible with a preloaded biliary catheter and a monorail technique for catheter positioning.

Use of self-expanding metal stents for palliation of rectosigmoid cancer

BACKGROUND

Patients with large bowel obstruction can be palliated by colostomy or by endoscopic modalities that restore luminal patency. The clinical results of a series of patients with rectosigmoid cancer in whom self-expanding metal stents were inserted at endoscopy are presented.

METHODS

Thirty-seven patients with symptoms related to obstructive rectosigmoid adenocarcinoma were treated by endoscopic insertion of self-expanding metal stents.

RESULTS

Metal stents were correctly placed in 36 of 37 patients (97%) with no immediate complications. Early dislodgment of the stent (within 1 week) was observed in 3 cases. The remaining 33 patients (92%) were followed for a median of 7 months (3 weeks-33 months). In 28 patients (78%) there was long-term restoration of luminal patency and disappearance of obstructive symptoms without further treatments. They experienced no pain, tenesmus, or incontinence during the follow-up period. The incidence of complications (early and late) and the mortality rate related to the procedure were 22% and 3%, respectively.

CONCLUSIONS

Endoscopic metal stents can be considered a simple and effective solution for long-term palliation of rectosigmoid cancer.

Current concepts in gastrointestinal photodynamic therapy

OBJECTIVE

To review current concepts of photodynamic therapy (PDT) applied to the treatment of tumors of the gastrointestinal tract.

SUMMARY BACKGROUND DATA

PDT initially involves the uptake or production of a photosensitive compound by tumor cells. Subsequent activation of the photoreactive compound by a specific wavelength of light results in cell death, either directly or as a result of vascular compromise and/or apoptosis.

METHODS

The authors selectively review current concepts relating to photosensitization, photoactivation, time of PDT application, tissue selectivity, sites of photodynamic action, PDT effects on normal tissue, limitations of PDT, toxicity of photosensitizers, application of principles of PDT to tumor detection, and current applications of PDT to tumors of the gastrointestinal tract.

RESULTS

PDT is clearly effective for small cancers, but it is not yet clear in which cases such treatment is more effective than other currently acceptable approaches. The major side effect of PDT is cutaneous photosensitization. The major limitation of PDT is depth of tumor kill. As data from current and future clinical trials become available, a clearer perspective of where PDT fits in the treatment of cancers will be gained. Many issues regarding pharmacokinetic data of photosensitizers, newer technology involved in light sources, optimal treatment regimens that take advantage of the pharmacophysiology of photoablation, and light dosimetry still require solution. One can foresee application of differing sensitizers and light sources depending on the specific clinical situation. As technologic advances occur, interstitial PDT may have significant application.

CONCLUSIONS

PDT has a potentially important role either as a primary or adjuvant mode of treatment of tumors of the gastrointestinal tract.