Advances in gastrointestinal intervention: the treatment of gastroduodenal and colorectal obstructions with metallic stents

Newly designed sheaths for gastroduodenal intervention: an experimental study in a phantom and dogs

Objective

To evaluate the usefulness of newly designed sheaths for gastroduodenal intervention in a gastric phantom and dogs.

Materials and Methods

A regular sheath was made using a polytetrafluoroethylene tube (4 mm in diameter, 90 cm long) with a bent tip (4 cm long, 100 degree angle). For the supported type of sheath, a 5 Fr catheter was attached to a regular sheath to act as a side lumen. To evaluate their supportability, we measured the distance of movement of the sheath's tip within a silicone gastric phantom for three types of sheath, the regular type, supported type, and supported type with a supporting guide wire. The experiments were repeated 30 times, and the results were analyzed using ANOVA with the postHoc test.

In addition, an animal experiment was performed in six mongrel dogs (total: 12 sessions) to evaluate the torque and supportability of the sheaths in the stomach, while pushing a guide wire or coil catheter under fluoroscopic guidance.

Results

In the guide wire application, the distances of movement of the sheath tip in the three types of sheath, the regular type, supported type, and supported type with supporting guide wire, were 8.40±0.51 cm, 6.23±0.41 cm, and 4.47±0.32 cm, respectively (p < 0.001). In the coil catheter application, the corresponding values were 7.22±0.70 cm, 5.61±0.31 cm and 3.91±0.59 cm, respectively (p < 0.001).

All three types of sheath rotated smoothly and enabled both the wires and catheters to be guided toward the pylorus of the dog in all cases.

Conclusion

The newly designed sheaths can be useful for gastroduodenal intervention.

Colon stenting: a review

Up to 85% of patients who present with colonic obstruction have a colorectal cancer. Between 7% and 29% of these patients present with total or partial intestinal obstruction. Only 20% of these patients presenting with acute colonic obstruction due to malignancy survive 5 years. Emergent surgical intervention in patients with colonic obstruction is associated with significant morbidity and mortality rates. Only 40% of patients with obstructive carcinoma of the left colon can be treated with surgical resection without the need for a colostomy. The use of a temporary or permanent colostomy has a significant impact on quality of life. The decompressive effect seen with colonic stenting is a durable, simple, and effective palliative treatment of patients with advanced disease. Stent deployment provides an effective solution to acute colonic obstruction and allows surgical treatment of the patient in an elective and more favorable condition. In addition, colonic stenting reduces costs and avoids the need for a colostomy.

Palliation of malignant gastroduodenal obstruction with open surgical bypass or endoscopic stenting: clinical outcome and health economic evaluation

Gastroduodenal outlet obstruction is a complication of advanced gastrointestinal malignant disease. In the past it was usually treated by an open surgical bypass procedure. During the last decade, endoscopic self-expandable stents (SEMS) have been used. The aim of this study was to compare these two palliative strategies concerning clinical outcome and health economy. A series of 36 patients with incurable malignant disease and gastroduodenal outlet obstruction syndrome were treated in a prospective study. According to the attending hospital and endoscopist on duty, 21 of the 36 patients were endoscopically treated with SEMS and 15 underwent an open surgical gastroenteroanastomosis. Health economic evaluation was based on the monetary charges for each patient associated with the procedure, postoperative care, and hospital stay. The hospital stay was 7.3 days for the stented group compared with 14.7 days for the open surgery group ( p > 0.05). The survivals were 76 and 99 days, respectively (NS). In the stented group all 15 patients (100%) alive after 1 month were able to eat or drink, and 11 (73%) of them tolerated solid food. In the surgical bypass group,9 out of 11 (81%) patients alive after 1 month could eat or drink, and 5 of them (45%) could eat solid food. The mean charges (U.S. dollars) during the hospital stay were $7215 for the stented group and $10,190 for the open surgery group ( p < 0.05). Palliation of the gastroduodenal obstruction in patients with malignant disease were at least as good, and the charges were lower for the endoscopic stenting procedure than for an open surgical bypass.

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Definitive palliation for neoplastic colonic obstruction using enteral stents: Personal case-series with literature review

Acute colonic obstruction due to malignancies is an emergency that requires surgical treatment. Elderly patients or inoperable tumors require intestinal decompression that is a simple colostomy in almost all cases. This “manoeuvre” leads the patient to a percentage of mortality/morbidity and to a bad quality of life due to acceptance of stoma. The introduction of enteral metal stent inserted endoscopically has, in our opinion, provided a new way to obtaining the definitive palliation of inoperable colo-rectal cancer with a simple method. We reported our case-series and we analyzed the current literature and costs of treatments.

Palliation of anastomotic obstructions in recurrent gastric carcinoma with the use of covered metallic stents: clinical results in 25 patients

BACKGROUND

The purpose of this study was to investigate the technical feasibility and the clinical effectiveness of the placement of covered self-expandable metallic stents for the treatment of anastomotic obstructions in recurrent gastric carcinoma.

METHODS

With fluoroscopic guidance, covered stents were placed in 25 patients with recurrent gastric carcinoma for the palliation of obstructions at anastomotic sites (14 gastrojejunostomy, 11 esophagojejunostomy). All patients had severe nausea and recurrent vomiting before the stent placement.

RESULTS

Stent placement was technically successful in 24 patients (96%). After stent placement, symptoms improved in all 24 patients. During the follow-up of 2 to 65 weeks (mean, 13.7 weeks), stent migration occurred in 1 patient 16 days after the procedure. He needed percutaneous catheter drainage because of an abscess, which was followed by esophagojejunostomy site rupture during a second stent trial. Stricture recurred in 4 patients because of tumor overgrowth 10 to 55 weeks after the procedure; all patients underwent coaxial placement of a second stent and had good oral intake.

CONCLUSIONS

The placement of covered expandable metallic stents seems to be both technically feasible and an effective means for the palliation of anastomotic obstructions in recurrent gastric carcinoma. This procedure can be considered to be the primary choice for the palliation in those patients.

Endoscopic stenting of colonic tumours

Self-expandable metal stents (SEMS) are useful for the non-surgical relief of malignant colonic obstruction. They may be used both as a palliative measure and as a pre-operative bridge to facilitate a one-stage surgical resection of primary colonic tumours. SEMS may be placed endoscopically or by interventional radiologists without the use of endoscopy. In experienced centres SEMS can be successfully placed in approximately 90% of cases. Although it is known that the placement of these devices is feasible, there are no prospective trials comparing stent placement for colonic obstruction to routine surgical care. Additionally, there are no studies comparing the outcome of the method of placement (endoscopic versus radiological). This chapter reviews the types of expandable metal stent used for treatment of colonic obstruction, the indications for their insertion, their methods of insertion, and outcomes following insertion. Future research directions using expandable stents for colonic tumours are also addressed.

Comparative observation on different intervention procedures in benign stricture of gastrointestinal tract

AIM: To determine the most effective intervention procedure by evaluation of mid and long-term therapeutic efficacy in patients of stricture of the gastrointestinal tract (GIT).

METHODS: Different intervention procedures were used to treat benign stricture of GIT in 180 patients including pneumatic dilation (group A, n = 80), permanent (group B, n = 25) and temporary (group C, n = 75) placement of expandable metallic stents.

RESULTS: The diameters of the strictured GIT were significantly greater after the treatment of all procedures employed (P < 0.01). For the 80 patients in group A, 160 dilations were performed (mean, 2.0 times per patient). Complications in group A included chest pain (n = 20), reflux (n = 16), and bleeding (n = 6). Dysphagia relapse occurred in 24 (30%) and 48 (60%) patients respectively during 6-and-12 momth follow-up periods in group A. In group B, 25 uncovered or partially covered or antireflux covered expandable metallic stents were placed permantly, complications included chest pain (n = 10), reflux (n = 15), bleeding (n = 3), and stent migration (n = 4), and dysphagia relapse occurred in 5 (20%) and 3 patients (25%) during the 6- and -12 month follow-up periods, respectively. In group C, the partially covered expandable metallic stents were temporarily placed in 75 patients and removed after 3 to 7 days via gastroscope, complications including chest pain (n = 30), reflux (n = 9), and bleeding (n = 12), and dysphagia relapse occurred in 9 (12%) and 8 patients (16%) during the 6-and-12 month follow-up periods, respectively. The placement and withdrawal of stents were all successfully performed. The follow-up of all patients lasted for 6 to 96 months (mean 45.3 ± 18.6 months).

CONCLUSION: The effective procedures for benign GIT stricture are pneumatic dilation and temporary placement of partially-covered expandable metallic stents. Temporary placement of partially-covered expandable metallic stents is one of the best methods for benign GIT strictures in mid and long-term therapeutic efficacy.

Stenting or stoma creation for patients with inoperable malignant colonic obstructions? Results of a study and cost-effectiveness analysis

BACKGROUND

The aim of the present study was to compare the efficacy, safety, and cost of endoscopic palliative treatment with selfexpanding metallic stents with that of stoma creation in the management of inoperable malignant colonic obstructions.

METHODS

A total of 30 patients with inoperable malignant partial obstruction (due to metastases, hemodynamic instability, or pulmonary instability) in the left colon arising from colorectal or ovarian cancer were included in the study. Fifteen were randomized to undergo palliative metallic colonic stent placement and 15 to undergo stoma creation. The efficacy and safety of the two methods was compared. A cost-effectiveness analysis was also performed, including the cost of postinterventional care.

RESULTS

Stents were placed successfully in 14 of 15 patients. In one patient with obstruction of a tortuous rectosigmoid flexure colon, stenting was not possible; this patient was excluded from the study. During the follow-up period, a moderate, nonocclusive ingrowth of tumor into the stent lumen was observed in six patients; they were all treated with internal laser ablation. The cost-effectiveness analysis showed that although the stoma creation procedure was less expensive, the total difference in average costs for the two methods was 6.9% (132 Euros).

CONCLUSIONS

Self-expanding metallic stent placement is a palliative alternative to colostomy for patients with inoperable malignant colonic strictures. This treatment option provides a better quality of life for the patient, without the psychological repercussions of a colostomy, and it appears to be cost-effective.

Complications of stent placement for benign stricture of gastrointestinal tract

AIM: To observe the frequent complications of stent placement for stricture of the gastrointestinal tract and to find proper treatment.

METHODS: A total number of 140 stents were inserted in 138 patients with benign stricture of the gastrointestinal tract. The procedure was completed under fluoroscopy in all of the patients.

RESULTS: Stents were successfully placed in all the 138 patients. Pains occurred in 23 patients (16.7%), slight or dull pains were found in 21 patients and severe chest pain in 2 respectively. For the former type of pain, the patients received only analgesia or even no treatment, while peridural anesthesics was conducted for the latter condition. Reflux occurred in 16 of these patients (11.6%) after stent placement. It was managed by common antireflux procedures. Gastrointestinal bleeding occurred in 13 patients (9.4%), and was treated by hemostat. Restenosis of the gastrointestinal tract occurred in 8 patients (5.8%), and was apparently associated with hyperplasia of granulation tissue. In 2 patients, the second stent was placed under X-ray guidance. The granulation tissue was removed by cauterization through hot-node therapy under gastroscope guidance in 3 patients, and surgical reconstruction was performed in another 3 patients. Stent migration occurred in 5 patients (3.6%), and were extracted with the aid of a gastroscope. Food-bolus obstruction was encountered in 2 patients (1.4%) and was treated by endoscope removal. No perforation occurred in all patients.

CONCLUSION: Frequent complications after stent placement for benign stricture of the gastrointestinal tract include pain, reflux, bleeding, restenosis, stent migration and food-bolus obstruction. They can be treated by drugs, the second stent placement or gastroscopic procedures depend on the specific condition.

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Follow-up evaluation for benign stricture of upper gastrointestinal tract with stent insertion

AIM: To determine the best mothod for benign stricture of the upper gastrointestinal tract (UGIT) with stent insertion by follow-up evaluation.

METHODS: A total of 110 stents insertions were performed in 110 cases of benign stricture of the UGIT. Permanent (group A) and temporary (group B) placement of an expandable metal stent in 30 cases and 80 cases respectively. All cases were completed under fluoroscopy.

RESULTS: In group A, 30 uncovered or antireflux covered or partially covered expandable metal stents were placed permanently. In group A, 5 cases (16.7%) in 3-months, 5 cases (20.0%) in 6-months, 6 cases (25%) in the 1st year, 6 cases (50%) in the 3^rd year, and 4 cases (80%) in the 5^th year exhibited dysphagia relapse. In group B, a partially-covered expandable metal stent was temporarily placed in each patient and removed after 3-7 d via gastroscopy. Follow-up data in this group showed that 8 cases (7.5%) in 3-months, 9 cases (12.0%) in 6-months, 10 cases (15.4%) in the 1^st year, 6 cases (20%) in the 3^rd year, and 3 cases (25%) in the 5^th year exhibited dysphagia relapse. The placement and withdrawal of all stents were all performed successfully. The follow-up of all cases lasted for 3-99 mo (mean 41.6 ± 19.7 mo).

CONCLUSION: The best mothod for benign stricture of UGIT with stent insertion is temporary placement of a partially-covered expandable metal stent.

Palliative treatment of inoperable malignant esophageal strictures with metal stents: one center's experience with four different stents

PURPOSE

Our center's experience with Ultraflex, Flamingo, SR stent and Flexstent for the palliation of malignant esophageal strictures is reported, and current pertinent literature is reviewed.

MATERIAL AND METHODS

Stents have been placed under fluoroscopic guidance between August 1993 and February 2002 for the palliation of malignant dysphagia in 116 patients. 59 patients received Ultraflex, 33 patients received Flamingo Wallstent, 20 patients received the SR stent and four patients received Flexstent.

RESULTS

Stent placement was successful in all the patients, with good symptomatic control in 123 out of 126 patients (98%) and no procedure-related complications. Four esophagorespiratory fistulas were successfully closed with covered Flamingo stents. Repeat intervention was necessary in 30 patients (51%) who received the Ultraflex stent, secondary to tumor ingrowth, overgrowth, ulceration, fistula and incomplete expansion. Two patients (6%) who received Flamingo Wallstent died due to gastrointestinal bleeding and one patient had proximal migration. Four patients (20%) who received the SR stent had complete migration of the stent.

CONCLUSION

Covered stents were found to provide better long-term palliation compared to uncovered stents. The covered Flamingo Wallstent seems to be the best choice of stent for lesions where crossing the esophagogastric junction is not necessary. For lesions where it is mandatory to cross the junction it may be preferable to use a stent with an antireflux mechanism.

Endoscopic palliation of colorectal cancer

Multiple endoscopic options exist for physicians seeking to provide palliative therapy for patients with colorectal cancer. Endoscopic decompression tubes can allow urgent stabilization for patients with malignant obstruction requiring some form of surgical palliation. Patients who are not candidates for palliative surgery can experience good symptomatic relief from malignant large bowel obstruction via laser therapy or placement of a colonic stent. Laser therapy can be used in conjunction with SEMS to recanalize and decompress large bowel in certain situations. The use of colonic stents is rapidly becoming more commonplace as acceptance of the technique becomes more widespread. Patients with unresectable disease may be able to avoid surgery altogether and achieve successful and lasting palliation of large bowel obstruction. Overall, they provide effective and durable palliation in patients with malignant obstruction, have an excellent risk/benefit profile, and are within the technical means of both gastroenterologists and interventional radiologists.

Palliative stenting of malignant large bowel obstruction

OBJECTIVE: Untreated malignant large bowel obstruction is rapidly fatal. Short-term palliation of symptoms can be achieved by formation of a stoma in those patients for whom resection surgery is inappropriate. In the final months of life, a stoma represents a significant burden for both patients and carers. Palliative endoluminal stenting may therefore be an attractive alternative option for this poor prognosis group. In this paper, we examine our experience of palliative endoluminal colonic stenting. PATIENTS: Twenty patients, 11 males and 9 females of median age 81 years were referred for stenting. All had left sided colonic cancers. Ten patients had confirmed metastases on presentation, four had fixed rectal cancers and the remainder had severe comorbidity limiting surgical options. Stents were placed endoscopically using a radiologically controlled 'stent over wire' technique. RESULTS: Stenting successfully relieved the obstruction in 18 of the 20 patients attempted. In one patient the stricture could not be negotiated and the procedure was abandoned. Eleven patients have died of their disease, their median duration of palliation was 50 days (3-152 days). The rest of the patients continue in follow-up and have had 80 days median palliation (14-257 days). One stent-related complication has been observed in a patient who suffered anal pain due to fracture and migration of part of a stent into the low rectum. This complication occurred after 250 days and the distal stent fragment was removed with further symptom relief. CONCLUSION: Carefully selected patients benefit from colonic endoluminal stenting with relief of obstructive symptoms. They may be spared the potential problems associated with palliative stoma formation.

Stenting for obstructing colorectal malignancy: an interim or definitive procedure

BACKGROUND

The purpose of this paper is to review and report our experience with colorectal stenting in the management of malignant large bowel obstruction.

METHODS

Twelve consecutive patients with malignant left-sided large bowel obstruction between June 1998 and January 2001 underwent insertion of self-expanding metallic stents. One patient required two stents. Eight stents were inserted under fluoroscopic guidance, and five were inserted with combined fluoroscopic and endoscopic guidance. Patients were followed up until death, stent removal or the time of publication.

RESULTS

Thirteen stents were inserted. Eleven patients with acute large bowel obstruction had relief of obstruction with stenting, and one of these patients required a second stent because relief had been incomplete. One patient was stented in order to subsequently close a problematic stoma. Technical success was 92.9% and clinical success was 100%. Three patients proceeded to surgical resection. In nine patients, the stent was left as the definitive procedure. Of these, six patients have died within 4 months. Complications included one case of migration, one case of reobstruction, one intestinal haematoma and one case of cheesewiring.

CONCLUSIONS

Colorectal stenting is an important treatment modality for malignant large bowel obstruction. It may be definitive treatment alone, or a bridge to elective surgical resection.

Surgical palliation in advanced disease: recent developments

Despite many valuable technical innovations for the relief of suffering in advanced disease over the past few years, only recently have surgical oncologists attempted to more clearly define palliation. Previous definitions have been misleading, creating confusion about the merits of surgery in many situations and difficulty in posing questions for future prospective clinical trials. This report outlines recent progress in identifying and refining a philosophy of palliative surgery that would align it with the consensus of nonsurgical opinion summarized by the 1990 World Health Organization definition of palliative care and the emerging consensus among the medical specialties in the United States concerning principles of care at the end of life. Selected controversies and recent innovations, as well as guidelines for palliative surgery, are discussed.

Radiological palliation of malignant colonic obstruction

PURPOSE

To evaluate the efficacy of colorectal stenting in the palliation of irresectable malignant colonic obstruction.

MATERIALS AND METHODS

Fifteen patients underwent colorectal stenting for irresectable colonic malignancy. Sixteen stents were placed successfully in 13 patients. Two stent insertions, one a proximal transverse colon lesion, were unsuccessful. Twelve patients (80%) had clinical or radiological features of imminent obstruction. Three patients were completely obstructed. Eighty-six percent of lesions were within the rectosigmoid colon.

RESULTS

Technical and clinical success was 88%. Early, minor complications occurred in two patients (13%). Late complications included migration (13%) and ingrowth (19%). The median survival was 2 months (0.5-12 months).

CONCLUSION

Stenting should be considered as definitive treatment in the context of an inoperable malignant stricture of the colon. It has low morbidity and a high technical and clinical success rate and avoids emergency defunctioning surgery in high-risk patients.

Fluoroscopically guided placement of a covered self-expandable metallic stent for malignant antroduodenal obstructions: preliminary results in 18 patients

OBJECTIVE

The purpose of this study was to investigate the technical feasibility and the clinical effectiveness of fluoroscopically guided placement of covered self-expandable metallic stents in the treatment of malignant antroduodenal obstructions.

SUBJECTS AND METHODS

With fluoroscopic guidance, covered self-expandable metallic stents were placed in 18 consecutive patients with inoperable malignant antroduodenal obstructions. All patients were treated for severe nausea and recurrent vomiting.

RESULTS

Stent placement was technically successful in all patients with or without gastrostomy (n = 2) and balloon dilatation (n = 3). After stent placement, symptoms improved in all but one patient, who had another stenosis in the proximal jejunum. During the follow-up of 2-73 weeks (mean, 12 weeks), stent migration occurred in three patients (16.7%) from 1 to 41 days after the procedure. These patients were treated successfully by means of placing a second covered metallic stent. Two patients, who were followed up for longer than 30 weeks, showed a recurrence of strictures because of mechanical failure of the stents; one of the patients was treated with coaxial placement of a second covered metallic stent, which had a positive clinical outcome.

CONCLUSION

Fluoroscopically guided placement of covered self-expandable metallic stents is technically feasible and effective for the palliative treatment of inoperable malignant antroduodenal obstructions. The rate of stent migration in our study was lower than those in previous reports.

Endoscopic palliation of malignant gastric outlet obstruction using self-expanding metal stents: experience in 36 patients

OBJECTIVE

Malignant gastric outlet obstruction is seen in the setting of a variety of cancers, most commonly pancreatic. Self-expanding metal stents can be used to palliate these patients and restore the ability to eat.

METHODS

We reviewed the Mayo Clinic experience in the endoscopic treatment of malignant gastric outlet obstruction. Thirty-six patients (26 male, 10 female) were treated between October, 1998 and January, 2001. Data were collected from charts, endoscopy reports, x-rays, and telephone calls. A scoring system was created to grade the ability to eat.

RESULTS

All procedures were successful. Thirty-one of 36 patients (86%) required one stent at initial endoscopy, and 5/36 patients (14%) required two or more stents. Pretreatment, 19/36 patients (53%) were nil per os, 15/36 (42%) drank liquids, and 2/36 were able to eat soft solids. After stent placement, only 1/36 (3%) was still nil per os, 13/36 (36%) drank liquids, 13/36 (36%) ate soft solids, and 9/36 (25%) ate a full diet. The improvement in ability to eat using the scoring system was statistically significant (p < 0.0001). Nine of 36 patients (25%) required reintervention for recurrent symptoms. Sixteen of 36 patients (44%) had concomitant or subsequent development of biliary obstruction, of which 15 were successfully decompressed.

CONCLUSIONS

Self-expanding metal stents are a safe and efficacious method for palliating malignant gastric outlet obstruction. The majority of patients do not require reintervention, and those that do can usually be managed nonoperatively.

Interventional endoscopy

Interventional endoscopy is a general label given to endoscopic procedures used to deal with a variety of gastrointestinal disorders. The interventional endoscopic procedures of interest in this review are those used specifically with gastric disorders. They include hemostasis, endoscopic ultrasound, endoscopic mucosal resection, stenting, percutaneous endoscopic gastrostomy tube placement and photodynamic laser therapy. Here, we review the latest data related to (a) a number of general issues having an impact on this diverse group of procedures (eg, such as proper patient selection criteria, consent in the era of open access endoscopy, protocol for anticoagulation, and sedation); (b) the methodology and outcomes of each of these unique procedures as they apply to the stomach; and (c) some of the latest technologic advances and developments that will potentially have an impact the future use of these procedures.

Initial experience with Song's covered duodenal stent in the treatment of malignant gastroduodenal obstruction

PURPOSE

Initial experience with use of Song's covered duodenal stent in the treatment of malignant gastroduodenal obstruction is reported.

MATERIALS AND METHODS

Sixteen consecutive patients with malignant gastroduodenal obstruction were treated with peroral placement of Song's covered duodenal stent. The mean age was 58 years (range, 28-90 y). Gastroduodenal obstruction was caused by gastric (n = 8), metastatic (n = 2), gallbladder (n = 3), pancreatic (n = 2), or ampullary (n = 1) cancer. The disease was considered inoperable in all patients. With use of a flexible 20-F introducing system, seven fully covered, three uncovered, and 10 partially covered duodenal stents were placed under fluoroscopic guidance.

RESULTS

The technical success rate was 94% (15 of 16) with no major complications. Symptoms of gastroduodenal obstruction improved in 14 patients. Stent migration was observed in three of seven fully covered stents. Patients with migrated stents required endoscopic stent removal and placement of uncovered duodenal stents. Tumor ingrowth was observed in two thirds of uncovered stents. In the 10 procedures with partially covered duodenal stents, no migration or tumor ingrowth was observed. All patients died 1-48 weeks (mean, 12 weeks) after stent placement.

CONCLUSION

Peroral placement of Song's covered duodenal stent is a feasible and effective method of palliation in the majority of patients with malignant gastroduodenal obstruction. Migration of fully covered stents and tumor ingrowth of uncovered stents are important limitations that can be overcome with the use of a partially covered duodenal stent.

The impact of new technology on surgery for colorectal cancer

Advances in technology continue at a rapid pace and affect all aspects of life, including surgery. We have reviewed some of these advances and the impact they are having on the investigation and management of colorectal cancer. Modern endoscopes, with magnifying, variable stiffness and localisation capabilities are making the primary investigation of colonic cancer easier and more acceptable for patients. Imaging investigations looking at primary, metastatic and recurrent disease are shifting to digital data sets, which can be stored, reviewed remotely, potentially fused with other modalities and reconstructed as 3 dimensional (3D) images for the purposes of advanced diagnostic interpretation and computer assisted surgery. They include virtual colonoscopy, trans-rectal ultrasound, magnetic resonance imaging, positron emission tomography and radioimmunoscintigraphy. Once a colorectal carcinoma is diagnosed, the treatment options available are expanding. Colonic stents are being used to relieve large bowel obstruction, either as a palliative measure or to improve the patient’s overall condition before definitive surgery. Transanal endoscopic microsurgery and minimally invasive techniques are being used with similar outcomes and a lower mortality, morbidity and hospital stay than open trans-abdominal surgery. Transanal endoscopic microsurgery allows precise excision of both benign and early malignant lesions in the mid and upper rectum. Survival of patients with inoperable hepatic metastases following radiofrequency ablation is encouraging. Robotics and telemedicine are taking surgery well into the 21^st century. Artificial neural networks are being developed to enable us to predict the outcome for individual patients. New technology has a major impact on the way we practice surgery for colorectal cancer.

Treatment of malignant digestive tract obstruction by combined intraluminal stent installation and intra-arterial drug infusion

AIM: To study the palliative treatment of malignant obstrution of digestive tract with placement of intraluminal stent combined with intra-arterial infusion of chemotherapeutic drugs.

METHODS: A total of 281 cases of digestive tract malignant obstruction were given per oral (esophagus, stomach, duodenum and jejunum), per anal (colon and rectum) and percutaneous transhepatic (biliary) installation of metallic stent. Among them, 203 cases received drug infusion by cannulation of tumor supplying artery with Seldinger’s technique.

RESULTS: Altogether 350 stents were installed in 281 cases, obstructive symptoms were relieved or ameliorated after installation. Occurrence of restenotic obstruction was 8-43 weeks among those with intra-arterial drug infusion, which was later than 4-26 weeks in the group with only stent installation. The average survival time of the former group was 43 (3-105) weeks, which was significantly longer than 13 (3-24) weeks of the latter group.

CONCLUSION: Intraluminal placement of stent combined with intra-arterial infusion chemotherapy is one of the effective palliative therapies for malignant obstruction of the digestive tract with symptomatic as well as etiological treatment.

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.

Adenocarcinoma of the small bowel

Cancer of the small bowel is a rare entity but its incidence is rising. Historically, outcome is poor despite apparent curative resection. At present surgery remains the only treatment modality of proven benefit in the management of this disease. Recent data would suggest 5-year survival rates in the order of 40-50% at all sites of small bowel cancer. To improve upon this, earlier diagnosis with a high index of suspicion and multicentre adjuvant therapy trials are required.

Long-term patency of experimental magnetic compression gastroenteric anastomoses achieved with covered stents

BACKGROUND

Our aim was to evaluate the efficacy of a prototype "YO-YO"-shaped covered stent for keeping experimental magnetic compression gastroenteric fistulas patent for 6 months.

METHODS

Magnets were introduced perorally with endoscopic and fluoroscopic guidance and were mated across the gastric and jejunal walls of 5 dogs. After a mean of 5.5 days a 12-mm diameter YO-YO stent was placed perorally in the resulting fistula. The gastroenteric anastomosis (GEA) with stent was observed endoscopically and gastrographically at 1- to 2-month intervals.

RESULTS

There was no morbidity and there were no significant weight changes. The GEA was widely patent at necropsy at 6 months (n = 4); partial membrane separation occurred at 5 months in the fifth dog. There was minor breakage of the stent prongs in 2 animals.

CONCLUSION

Peroral creation of a stented magnetic compression GEA is safe and provides long-term patency. This technique may be potentially useful for managing gastric outlet obstruction caused by malignancy.