Flexible Fiberoptic Endoscopy Research Articles

Experimental evaluation of an endoscopic ultrasound probe: In vitro and in vivo canine studies

We developed an endoscopic echo probe that can be passed via the biopsy channel of a flexible fiberoptic or video endoscope with a 3.5-mm channel. The probe moves along the gastrointestinal wall under direct endoscopic vision. The translational scanning action is sensed by a position potentiometer and combines with the ultrasonic B-mode echoes to produce a cross-sectional image of the wall. The system uses an ultrasound frequency of 20 MHz to produce high-resolution images. The device was used to image canine gastrointestinal tissue in vitro and in vivo during endoscopy. Ultrasound images of the gut wall correlate with histologic structure. This probe overcomes some of the problems associated with the combined ultrasound endoscopes now in use. Use of the probe with video endoscopy allows the endoscopic and ultrasound images to be displayed side by side, simplifying coordination of application of the two techniques.

Fiberoptic rhinolaryngoscopy in primary care

Modern flexible fiberoptic ear, nose, and throat (ENT) endoscopes have made office rhinolaryngoscopy an easily learned and practical option for most primary care physicians. Adoption of this procedure not only increases the comprehensiveness and quality of care but is economically justifiable in the current reimbursement environment and reinforces the primary care physician's function as a cost-effective manager of the patient's health. Rhinolaryngoscopic examination using a flexible fiberoptic ENT endoscope is simple to learn, and the diagnostic yield is far superior to that obtained with traditional rigid right-angle telescopic laryngoscopes. Rhinolaryngoscopy is an ideal area in which primary care physicians can extend their clinical expertise with maximum benefit to both their patients and themselves.

Flexible Fiberoptic Endoscopy for Airway Problems in a Pediatric Intensive Care Unit

We used flexible fiberoptic endoscopy to evaluate 87 patients with potential problems of the airway in a pediatric intensive care unit. Four different-sized bronchoscopes were used to perform 61 diagnostic laryngoscopic procedures, 35 diagnostic bronchoscopic procedures, and eight therapeutic bronchoscopic procedures. Diagnostic information was obtained in 91 of 96 procedures. Of the eight therapeutic procedures, seven were considered successful. Morbidity was minimal, and there was no death. Flexible fiberoptic endoscopy proved useful as a bedside technique for critically ill pediatric patients in whom evaluation of the airway in the operating room under general anesthesia would have been difficult.

Endoscopy in colonic volvulus.

Flexible fiberoptic gastrointestinal endoscopy has greatly simplified the diagnosis and treatment of colonic volvulus. The management of 39 patients with colonic volvulus treated over 9 years was reviewed. Five per cent were treated with rectal tube decompression alone, 23% were treated with either sigmoidoscopic or colonoscopic reduction, and 26% were treated exclusively with operation. Endoscopic reduction was attempted in nearly half of the patients in preparation for operation. Recurrent volvulus occurred in 57% of patients initially treated with endoscopic reduction alone. Sigmoidoscopic examination did not confirm the diagnosis in 24% of instances in which it was used, although colonoscopy was always diagnostic. The overall mortality rate was 8%, but increased to 25% in patients with gangrene of the colon. Three patients who later proved to have gangrene of the colon had a normal initial sigmoidoscopic examination. Two of these patients died of intra-abdominal sepsis from a perforated colon. In five patients an accurate endoscopic diagnosis of gangrene prompted immediate exploration. None of these patients died. Endoscopy is a safe and effective diagnostic tool for the initial evaluation of patients with suspected colon volvulus. In addition, endoscopy may result in therapeutic decompression and may provide visual assessment of the viability of the bowel mucosa, thus assisting in the timing of appropriate operative treatment.

A multipurpose overtube for diagnostic and therapeutic flexible fiberoptic endoscopy

A newly devised overtube for diagnostic and interventional endoscopy has been used in 140 cases. In 60 cases of acute gastrointestinal bleeding, adequate gastric lavage was completed in 14.1 +/- 1.3 min, using an average of 7.5 +/- 0.69 liters; the volume of fluid recovered was 103.9 +/- 0.58% of the volume infused. This tube also allows simultaneous gastric lavage and esophageal or gastric tamponade, enabling therapeutic intervention with sclerotherapy or bipolar coagulation in the patient with acute massive bleeding. This device can be employed for the removal of bezoars, foreign bodies, and multiple polyps.

Modern imaging and endoscopic biopsy techniques in Egyptian mummies.

Egyptian mummies have been popular subjects of radiographic investigation since 1896. Computed tomography (CT) and magnetic resonance imaging (MRI) have recently been added to the growing list of modern techniques used to study these relics. The Minnesota Mummy Project was organized to examine four well preserved Egyptian mummies dating from the XVIIIth (1575-1308 B.C.) and XXVth (715-663 B.C.) Dynasties. Plain radiographs and CT scans were obtained on all specimens. One individual was selected for additional endoscopic and microscopic correlation with CT findings in the thoracic cavity. The collapsed heart was identified by CT. A percutaneous biopsy of the heart was then performed with a flexible fiberoptic endoscope, passed through a small hole drilled into the chest wall. Microscopy of prepared ventricular specimens revealed striated muscle fibers consistent with myocardium. These results emphasize the utility of CT as a noninvasive paleoradiologic tool. Another mummy was examined by MRI to search for minute quantities of residual moisture possibly trapped within the desiccated tissues. Only a free-induction-decay signal could be obtained, but this was insufficient to generate an image. Thus, it appears that present MRI is not suitable for the paleopathologic investigation of dehydrated structures.

Biopsy of ureteral tumor in patient with ileal conduit

A patient with ileal conduit and recent dilation of the left upper collecting system had flexible fiberoptic endoscopy of the ileal loop. The entire lumen of the intestinal conduit and the ureteroileal anastomosis were visualized. In addition retrograde pyelography and direct vision biopsy of a tumor in the ureter were performed.

The role of fibreoptic oesophagogastroscopy in E.N.T. practice.

Fibreoptic endoscopy has only recently become used as a diagnostic tool for the E.N.T. surgeon but it has not been widely used in the investigation of pharyngeal disease. During a two-year period at Warwick Hospital 53 patients have undergone flexible fibreoptic endoscopy using a gastroscope, with visualization of the pharynx, larynx and upper G.I. tract as far as the duodenum. This report describes the technique employed, details the endoscopic findings in 53 patients, and discusses the indications for the technique and the advantages that it holds for the E.N.T. surgeon in the diagnosis and management of pharyngeal disease.

Nasogastric Intubation as Sole Treatment of Caustic Esophageal Lesions

In this partly retrospective and partly prospective study, we examined 200 patients with suspected caustic ingestion. No steroids were administered to the patients involved. Lesions in the esophagus were found in 93 patients. Thirty-two patients with deep circular burns had nasogastric tubes inserted immediately. Of these patients, two developed esophageal strictures, but subsequent dilatation was successful. No stricture formation was observed in the group of patients with noncircular lesions. We feel that this low percentage of stricture formation is due to the use of nasogastric tubes. Since neither the presence nor the severity of esophageal burns is predictable, an endoscopy should be performed in all suspected cases. In the absence of severe pharyngeal lesions, the use of a flexible fiberoptic endoscope is preferable because it also allows examination of the stomach and proximal part of the duodenum.

The fiberoptic endoscopy training program in an academic department of surgery

It has been our belief for many years 1 ,2 that flexible fiberoptic endoscopy is an integral part of the training and practice of both surgeons and internists caring for patients with diseases of the gastrointestinal tract. A general surgery resident or gastroenterology fellow who does not develop the understanding and ability to evaluate and treat patients endoscopically has been incompletely educated. 3 The American Board of Sur­ gery has encouraged general surgery residency pro­ grams to include endoscopic education and training. 4 We believe that it is an obligation of the general surgery residency program director to provide endo­ scopic training for those residents who need and desire it. There are many ways of providing endoscopy edu­ cation and training for surgical residents. Rotations on gastroenterology services have been successful at some institutions. 5 We believe that there is adequate clinical material in most surgical programs to support a separate surgical endoscopy training program 6 and would encourage this approach. The method of setting up endoscopic training programs should encourage collaboration and avoid destructive competition be­ tween gastroenterologists and surgeons. Reasonable people who believe that endoscopy is only a small but integral part of the practice of medical and surgical gastroenterology should be able to work together ef­ fectively in designing parallel or combined endoscopic training programs. For the past 10 years, training in flexible endoscopy has been integrated into the University of Michigan general surgery residency program. At the present time, each of six residents spends a two-month rota­ tion in surgical endoscopy during their third year (of five) of clinical training. They are taught by seven general surgery faculty who are expert endoscopists. As with all other aspects of our residency program, structured didactic and graduated practical experience is provided. There is liberal use of case discussions, slide-tapes, videotapes, color atlases, teaching models, scientific publications, and instructional manuals. During the initial orientation of each resident, it is emphasized that the primary goal of this concentrated endoscopic experience is to focus on gastrointestinal diseases and to understand the role endoscopy plays in the evaluation and treatment of each patient. The mastery of endoscopic technique is important but secondary to the primary educational goal. By mutual agreement with a supportive Division of

A balloon designed for endoscopic variceal sclerotherapy

Endoscopic injection of esophageal varices with sclerosing agents is a relatively old technique first reported by Craaford and Frenchner in 1939 and used throughout the 1940s. During its early stages, endoscopic variceal sclerotherapy (EVS) fell into disuse because rigid esophagoscopes required general anesthesia and because of the impression that portacaval shunting was a superior form of therapy. Portal shunting prevents recurrent variceal hemorrhage; however, it is associated with high operative mortality and morbidity from hepatic failure. 4 A resurgence of interest in EVS over the last decade has primarily been due to both the introduction of flexible fiberoptic endoscopy and the unsatisfactory results of surgical intervention. The techniques of EVS vary widely. Currently used balloons range from condoms to modified endotracheal cuffs. Many endoscopists use pneumatic balloons secured to the distal tip of the endoscope in an attempt to improve sclerosant injection and retention time and to enable direct tamponade of varices in the event of bleeding. The use of a balloon in this manner has not been systematically evaluated and has been controversial. One reason for controversy is that no data exist to document the relationship between the measured internal balloon pressure and actual transmission of pressure to the esophageal wall. Variability in pressure transmission may account for variable results. We have measured the actual pressure transmitted to the esophageal wall by balloons and have developed a balloon which transmits pressure on a one-to-one basis.

Comparison of automated systems for the cleaning and disinfection of flexible fibreoptic endoscopes

A comparison of four cleaning and disinfection machines is described. These varied considerably in design and function and although no single machine possessed all the preferred characteristics, cleaning and disinfection, particularly between patients, was substantially improved. Before purchasing a machine it is recommended that the user ensures that it is convenient to operate, effective in removing soil and bacteria, and adaptable to the range of fibrescopes used within the unit. Infections are often caused by Gram-negative bacilli which are particularly difficult to remove manually from moist narrow channels of the fibrescope and perfusion of all channels including the air channel, is, therefore, recommended. Thorough cleaning and disinfection will not only reduce the likelihood of infection but will also reduce channel blockages and the general deterioration of the fibrescope.

Flexible Fiberoptic and Rigid-Rod Lens Endoscopy of the Lower Urinary Tract: A Prospective Controlled Comparison

Cystourethroscopy was performed on 80 men by separate examiners with a rigid-rod lens instrument and a flexible fiberoptic choledochonephroscope. Findings with the flexible system were equivalent to or more accurate than those with the rigid endoscope in 94 per cent of the cases. With the flexible instrument the duration of the examination was unchanged, patient comfort was improved, the amount of irrigation fluid was reduced, and patient preparation and positioning were simpler and quicker.

Changes in the Mucosa of Colon Conduits With Particular Reference to the Risk of Malignant Change

Summary— Intestinal suction biopsies were obtaineid in 15 infants and children with cutaneous colo-ureterostomies. The patients were subdivided into groups according to the length of time the conduit had been established, i.e. less than 5 years, 5 to 10 years, 10 to 15 years and over 15 years. The histological changes found were chronic inflammation with a dense infiltration of plasma cells and eosinophils. The changes were progressive and correlated with the length of time the conduit had been established. As persistent chronic inflammation is a precursor of malignancy, it seems likely that there is a risk of malignant change in these conduits. Regular follow-up of such patients is recommended and should include flexible fibreoptic endoscopy of the conduit.

Changes in the mucosa of colon conduits with particular reference to the risk of malignant change.

Intestinal suction biopsies were obtained in 15 infants and children with cutaneous colo-ureterostomies. The patients were subdivided into groups according to the length of time the conduit had been established, i.e. less than 5 years, 5 to 10 years, 10 to 15 years and over 15 years. The histological changes found were chronic inflammation with a dense infiltration of plasma cells and eosinophils. The changes were progressive and correlated with the length of time the conduit had been established. As persistent chronic inflammation is a precursor of malignancy, it seems likely that there is a risk of malignant change in these conduits. Regular follow-up of such patients is recommended and should include flexible fibreoptic endoscopy of the conduit.

A simple method for cleaning flexible fibreoptic endoscopes by ‘all-channel perfusion’

There is an increasing awareness of the need to prevent infections caused by contaminated flexible fibreoptic endoscopes. Careful ‘manual’ cleaning, followed by perfusion of the air/water channel as well as the suction/biopsy channel (‘allchannel perfusion’) is, in our opinion, the procedure of choice. Although several endoscope washers have recently been marketed, none has an arrangement for simultaneous perfusion of all channels. Two instruments which automatically perfuse all channels followed by drying, have recently been described (Huibregtse et al., 1981; KeyMed, 1982), but the major drawback with these new cleaning instruments is the technical expertise required to build them. In addition, they need a small motor to activate the air/water and suction feed buttons to ensure perfusion of all channels. Simultaneous perfusion is technically not possible with the feeding buttons in place. We have developed a simple method to disinfect all channels of fibre-endoscopes with removable suction and air/water feeding buttons (i.e. all recently developed ‘Olympus’ fibreoptic endoscopes).

Colonoscopic removal of a foreign body causing colocutaneous fistulas

a Maloney dilator of a size slightly larger than the endoscope. Passage of the dilator should also open the cricopharyngeus and make it easier for the patient to swallow the instrument. The Maloney dilator was not used in this study because it was assumed that an adequate diameter was present if the patient did not have early dysphagia for solid foods. Sanders has described a balloon-tip for the flexible fiberoptic endoscope which facilitates blind passage of the instrument, but it has the disadvantage of blocking the visual control of the tip as soon as the balloon is inflated. Even when passing the endoscope under direct vision, the operator never knows for certain whether the esophagus lies to the left or right of midline. Some probing with the endoscope is necessary to find the

Gastrointestinal Tract Bleeding of Unknown Origin

Gastrointestinal (GI) tract bleeding of unknown origin is a vexing clinical problem. In this review, we discuss those causes of GI tract hemorrhage most likely to escape detection by conventional diagnostic modalities and explain how newer techniques of flexible fiberoptic endoscopy, radionuclide scanning, and angiography may be used to establish a diagnosis. We reviewed the literature on the role of exploratory surgery in the diagnosis of occult GI tract bleeding and conclude that its diagnostic yield is small and its value limited. Finally, we present a diagnostic approach to the patient with GI tract bleeding of unknown origin.

Injection sclerotherapy of bleeding oesophageal and gastric varices using a flexible endoscope.

Thirteen patients with acute or recent bleeding from gastro-oesophageal varices were treated by sclerotherapy using flexible fiberoptic endoscope. Primary haemostasis was obtained in 10 of 11 admissions with active bleeding. Three patients have been treated for gastric varices with the same method. Such treatment has not been reported before. During the follow-up period, three patients died, two of variceal haemorrhage and one of pneumonia. Ten patients are still alive 2-53 months after the first admission. A total of 117 treatment courses were given, on an average 9 per patient. Complications included superficial mucosal necrosis without clinical consequences in several cases, 3 patients developed oesophageal and gastric ulcers and one moderate oesophageal stenosis. Rebleeding occurred in 4 patients, in 2 of them because of ulcers at the sites of injections.

A new flexible fiberoptic nasopharyngolaryngoscope.

A new flexible fiberoptic endoscope for examination of the nasopharynx and larynx is presented. Its main advantages over the existing fiberoptic instruments consist in the extended flexibility of the tip, and its small diameter.