Design of a microwave system for endoscopy: an experimental study of energy, tissue contact, and hemostatic efficacy

Microwave coagulation versus sclerotherapy after band ligation to prevent recurrence of high risk of bleeding esophageal varices in Child-Pugh's A and B patients

BACKGROUND

The combination of endoscopic band ligation (EBL) with either endoscopic injection sclerotherapy (EIS) or thermal therapy has been shown to reduce recurrence of esophageal varices compared to EBL alone. The aim of this prospective trial was twofold: 1) to evaluate the safety and efficacy of EBL used in association with microwave coagulation (MC), a thermal endoscopic therapy method, for treating esophageal varices and preventing recurrence; and 2) to compare these results to the joint application of EBL and EIS.

METHODS

Seventy cirrhotic patients with bleeding esophageal varices were treated with EBL until only thin vessels remained. Thirty-six randomly selected patients received EIS (group A) and 34 received MC (group B) until complete eradication had been achieved. Endoscopic follow-up was performed to detect recurrence. The effectiveness of the treatment was measured using variceal recurrence, rebleeding, intervention complications, and recurrence factors.

RESULTS

During follow-up evaluations averaging 34.9 +/- 11.4 months, no significant differences were found between groups A and B in variceal recurrence (27.7 vs. 17.6%, P = 0.31) or rebleeding (8.3 vs. 0%, P = 0.23). Complications were rare, with no difference detected between groups. The presence of gastric varices influenced recurrence with an odds ratio of 3.9 (95% CI 1.14-13.1, P = 0.029).

CONCLUSIONS

Application of MC to esophageal varices after band ligation is safe. The post-MC recurrence rate may be comparable to that observed following the combined treatment of EBL and EIS. The presence of gastric varices increases the risk of esophageal variceal recurrence.

Low-dose oral methotrexate for maintaining Crohn's disease remission: where we stand

Methotrexate has been considered a second-line immunomodulating therapy, behind azathioprine (AZA) or its metabolite 6-mercaptopurine (6-MP), for the treatment of Crohn's disease (CD). Approximately 27% to 50% of patients with refractory CD are intolerant or resistant to AZA or 6-MP. Two well-designed randomized double-blind placebo-controlled trials have demonstrated that low-dose methotrexate (<25 mg/wk), given intramuscularly (IM), is effective in inducing and maintaining remission in CD. In clinical practice, IM injection involves an inconvenience for patients and higher costs. Furthermore, frequent IM injections increase the risk of complications such as peripheral nerve injury, local irritation, pain, bleeding, fibrosis, abscess formation, gangrene, and contractures. Alternatively, subcutaneous (SQ) injection has been advocated because it has been shown to have similar pharmacokinetics to IM injection. However, because of a recent and ongoing national shortage of parenteral methotrexate, patients who were receiving IM methotrexate had to switch to the oral form until the parenteral formulation becomes available. Oral methotrexate has been used with great success in treatment of rheumatoid arthritis and psoriasis for the past 50 years. However, the data on the usage of low-dose oral methotrexate in maintaining CD remission are scanty and controversial. The purpose of this article is to review the mechanism of action, absorption, and the objective evidence in supporting the use of oral methotrexate in maintaining CD remission.

Mechanical endoscopic methods of haemostasis for bleeding peptic ulcers: a review

Re-bleeding following endoscopic therapy for gastrointestinal bleeding remains common probably because injection and thermal methods for treating bleeding are of limited efficacy, especially in the presence of a large bleeding artery. This chapter reviews mechanical methods of endoscopic haemostasis. The design of clips, which can be delivered through flexible endoscopes, is reviewed with experimental and clinical data of their efficacy. The need for improvements in clip design is stressed. Experimental studies and preliminary clinical data where available on a variety of other mechanical methods of haemostasis are presented, including band ligation, endoloops, sewing machines, stapling machines, ulcer clamps, corkscrews, balloon tamponade and ferromagnetic tamponade. New, less invasive, surgical methods which might have a place in ulcer haemostasis, including transgastric endoluminal surgery and flexible endoscopic ulcer excision with wound closure, are discussed. Mechanical methods offer the best prospect for improvements in security of endoscopic haemostasis for bleeding peptic ulcer. More development is required if the results are to improve.

Current status of endoscopic therapy for ulcer bleeding

This article provides an overview of the therapeutic endoscopic modalities available for the treatment of peptic ulcer bleeding. The benefits of endoscopic haemostasis have been fully demonstrated by three meta-analyses, which included most of the controlled trials published until 1992. In this review, an emphasis is placed on randomized, prospective comparative trials published during the past 20 years. Using an evidence-based medicine approach, the results of meta-analyses are translated into efficacy measures known as relative and absolute risk reductions, and number needed to treat. Single-modality treatments with injection agents such as epinephrine, sclerosants and thrombogenic substances, or with thermal therapies, are efficacious and comparable. Combination therapy involving injection and thermal techniques may offer an advantage over single-method therapy. The differences in the results between clinical trials and routine clinical practice, and among the various randomized studies, are probably related to operators' experience and variations in technique rather than to inconsistency of endoscopic haemostasis.

Development and application of endoloops for the treatment of bleeding esophageal varices

BACKGROUND

Endoloops are detachable nylon snares. The aims of this study were to develop an endoscopic method for repeated delivery of endoloops to arrest variceal bleeding, to compare efficacy of endoloop hemostasis with injection and band ligation in experimental models of bleeding, and to test the reliability and safety of endoloops in a pilot study in patients with varices.

METHODS

Technical modifications including ridged endcaps and alterations in angulation of endoloops were developed to speed delivery and improve efficacy. Hemostatic efficacy of endoloops was compared with sclerotherapy and band ligation in animal studies before studies in patients.

RESULTS

Modified endcap and endoloops allowed repeated applications without withdrawal of the endoscope. Right-angled endoloops ensnared more (p < 0.0001) gastric tissue and were more reliable (p < 0.05) than straight endoloops. Injection therapy and prestretched bands appeared ineffective, whereas band ligation was only effective on vessels up to 2 mm in diameter. Only endoloops achieved hemostasis on vessels of 3 to 5 mm (p < 0.05). No significant complications occurred using endoloops in animal (esophagus n = 20, stomach n = 20) or human (n = 11) studies.

CONCLUSIONS

Endcap and endoloop modifications simplified repeated application to varices. Endoloops were more effective than injection or band ligation in experimental hemostasis and appeared safe and effective in patients.

Microwave endometrial ablation: development, clinical trials and outcomes at three years

OBJECTIVE

To describe the introduction of microwave endometrial ablation to clinical practice, and to report the outcomes three years after endometrial ablation.

DESIGN

A clinical trial using prototype microwave endometrial ablation equipment.

SETTING

District general hospital.

POPULATION

Forty-three women with completed families and with failed medical management for menorrhagia were treated with microwave endometrial ablation between October 1994 and April 1995.

MAIN OUTCOME MEASURES

A statement of perceived menstrual loss and satisfaction supported by a menstrual symptom questionnaire score. Dysmenorrhoea was graded as a measure of described severity. Treatment time.

RESULTS

Forty-three women had a total of 46 treatments. Mean treatment time: n = 43, was 141 seconds (50-310). Amenorrhoea: n = 16; 37.2%. Very light periods/discharge: n = 11; 25.6%. Improved periods and woman satisfied: n = 9; 20.9%. Improved periods and woman not satisfied: n = 1; 2.3%. Overall satisfaction at three years is 83.7%. Moderate (55.8%) or severe (27.9%) dysmenorrhoea pre-operatively had improved to 11.6% and 6.8% respectively at three years. Three re-treatments and four hysterectomies will be discussed.

CONCLUSIONS

Microwave endometrial ablation is a new treatment for dysfunctional uterine bleeding using the application of microwave energy to the endometrium. This results in a rapid but restricted depth of intrauterine heating avoiding hysteroscopic fluid, operative haemorrhage and earthing risks. The technique is simple to learn and perform. Women report a high level of satisfaction three years after microwave endometrial ablation.

Methotrexate in refractory Crohn's disease

BACKGROUND

Recent trials suggested that methotrexate may be effective in refractory Crohn's disease (CD). We analyzed the data of 20 patients treated with methotrexate because of corticodependent or refractory CD.

METHODS

Between January 1995 and June 1997, 20 azathioprine-resistant or -intolerant patients with active CD requiring continuous glucocorticosteroid treatment were treated with parenteral methotrexate. Clinical response was assessed by the Harvey-Bradshaw clinical activity index. Concomitant steroid use and steroid withdrawal rates were recorded. Patients were assessed at 12 weeks, 6 months, 9 months, and 12 months after the start of methotrexate therapy.

RESULTS

At 12 weeks, a clinical response was obtained in 14/20 patients (70%). These response rates decreased to 10/20 patients at 6 months, 8/17 patients at 9 months, and 4/14 evaluable patients at 12 months. In initial responders (n = 14), maintenance of remission was observed in 9/14, 6/11, and 3/9 patients at 6, 9, and 12 months, respectively. Methotrexate allowed corticosteroid tapering in 85% of patients and discontinuation in 60% of patients at 6 months. Side effects were rather frequent but usually mild and prompted discontinuation in two patients.

CONCLUSIONS

In this retrospective study, parenteral methotrexate appeared to be effective in inducing a clinical response in 70% of azathioprine-resistant or -intolerant CD patients and often permitted corticosteroid tapering, with an acceptable short-term toxicity. The potential of methotrexate to maintain long-term remission in refractory patients, however, appears less convincing.

Comparison of the hemostatic efficacy of the endoscopic hemoclip method with hypertonic saline-epinephrine injection and a combination of the two for the management of bleeding peptic ulcers

BACKGROUND

The endoscopic hemoclip method is a safe and effective hemostatic method for managing bleeding peptic ulcers. We compared the hemostatic efficacy of the endoscopic hemoclip method with that of hypertonic saline-epinephrine (HSE) injection and a combined method in the management of bleeding peptic ulcers.

METHODS

From July 1994 to July 1997, we conducted a randomized clinical trial of endoscopic hemostasis involving 124 patients with actively bleeding or visible vessels at endoscopic inspection.

RESULTS

Patients were randomly assigned to hemoclip (41 patients), HSE (41 patients), and combined treatment groups (42 patients). Initial hemostasis was achieved in 97.6%, 95.1%, and 97.6% of cases, respectively. Recurrent bleeding developed in 2.4%, 14.6%, and 9.5% of cases. Emergency operations were performed in 4.9%, 14.6%, and 2.3% of cases. The hemostasis rate was 71.4%, 50%, and 66.7% for spurting hemorrhage in each group. Permanent hemostasis was achieved in 95.1%, 85.4%, and 95.2% of cases. Three patients had complications, all in the HSE group.

CONCLUSIONS

The hemoclip method is an effective hemostatic procedure and is safer than HSE injection. The combined method does not provide substantial advantage over use of the hemoclip method alone in the hemostatic management of bleeding peptic ulcers.

Antireflux operations at flexible endoscopy using endoluminal stitching techniques: an experimental study

BACKGROUND

Three antireflux operations-gastroplasty, fundoplication, and anterior gastropexy-were developed for performance at flexible endoscopy without laparotomy or laparoscopy.

METHODS

An endoscopic sewing machine mounted on a standard gastroscope, endoscopic knotting devices, overtube, and nylon thread were used to perform these operations in adult beagle dogs.

RESULTS

Gastroplasty (n = 10) was accomplished by suturing the anterior and posterior wall of the stomach to create a gastric tube (neoesophagus) along the lesser curve. An anatomic arrangement similar to fundoplication (n = 6) was achieved by invaginating the esophagus and fixing it to the stomach 2 cm distal to the cardioesophageal junction. Anterior gastropexy (n = 6) was performed using a technique similar to that used in creating percutaneous gastrostomies. There was no mortality. Ninety percent of sutures were seen at repeat endoscopy at 4 to 8 week intervals. The gastroplasty group was selected for more extensive evaluation. Manometry using a three-channel perfused catheter system before and after the procedures showed an increase in the lower esophageal sphincter pressure (preoperative median 4.6 mm Hg; post-operative median 13.33 mm Hg, p = 0.008) and cardiac yield pressures (preoperative median 10 mm Hg; postoperative median 19 mm Hg, p = 0.007).

CONCLUSIONS

This study demonstrates the feasibility of performing antireflux operations at flexible endoscopy, without laparoscopy or laparotomy, by use of endoluminal suturing techniques.

Prolonged evaluation of epinephrine and normal saline solution injections in an acute ulcer model with a single bleeding artery

BACKGROUND

Animal studies of epinephrine or normal saline solution injection for bleeding ulcers do not consistently demonstrate local tamponade effect.

METHODS

We studied the change of bleeding rates of 28 acute gastric ulcers with a single bleeding artery in 10 dogs. Four injections of 1 mL epinephrine 1:10000 at 1 mm from the spurting artery (n = 7) were compared to four injections of normal saline solution 1 to 5 mL (n = 12) and to four dry needle sticks (n = 9). Bleeding rates were measured at initial arterial incision and at minutes 1, 5, 10, 15, 20, 25, and 30 after treatment.

RESULT

Reductions in early blood loss to 24.3% +/- .05 of baseline occurred with saline solution, to 17.7% +/- .03 with epinephrine, and to 66.0% +/- 1.8 in controls (p < .05 for epinephrine and saline solution vs control). A tendency for saline solution injected ulcers to resume bleeding was identified, with late blood loss increasing to 26.9% +/- .05 of baseline, (saline solution vs control) compared to 7.7% +/- .02 in epinephrine injected ulcers (p < .05 vs control).

CONCLUSIONS

The early acute hemostatic effect of injection therapy depends on local tamponade. The prolonged hemostatic effect is a combination of tamponade and vasoconstriction, with advantage of epinephrine over saline solution.