PubMed Health⌕ Search

Biomedical subjects

D H Birkett

Publications and source records attributed to D H Birkett.

At least 19 recordsLinked to original sources
PubMed1992

Laser lithotripsy for the management of retained stones.

The morbidity of reoperation for retained biliary stones is not significant. Many techniques have been developed to avoid reoperation. This study analyzes T-tube tract choledochoscopy and lithotripsy using a 504-nm pulsed dye laser for treatment of retained stones. A flexible choledochoscope is passed into the biliary tract and laser energy is delivered under endoscopic visualization after passing a 320-microns laser fiber through the instrument channel. Eight patients were treated in nine sessions. The mean number of pulses was 1512.33, delivered at 3 to 5 Hz with an energy of 100 to 120 mJ. In all patients, the biliary tract was cleared. A single patient's treatment was complicated by transient bacteremia. Mean follow-up was 10 months. Choledochoscopic laser lithotripsy is a safe, effective technique that may also play a major role in laparoscopic common duct surgery.

Boston↗
PubMed1992

Comparison of a pulsed dye laser and electrohydraulic lithotripsy on porcine gallbladder and common bile duct in vitro.

With the advent of minimal access biliary procedures there is a need for a safe intracorporal lithotripsy technique that can be used through small flexible endoscopes. Currently, the two techniques available are electrohydraulic lithotripsy and laser induced shock wave lithotripsy. In this study we compare the effect of a 504 nm coumarin pulsed dye laser and electrohydraulic lithotripsy on in vitro porcine gallbladder and common bile duct. Electrohydraulic lithotripsy at the lowest energy the generator would deliver caused perforation of both tissues in only a few pulses when a 1.9-F probe was placed in direct contact with the tissue. Energy from a 504 nm coumarin pulsed dye laser delivered through a 320-microns fiber placed in light contact with the tissue caused an energy-dependent perforation after 50 pulses in from none to 44% of tissues. It was also found that there was a higher incidence of perforation in more vascular than non-vascular tissue. When the EHL probe and the laser fiber were held 1-2 mm from the tissue surface, discharge of each resulted in no perforation. On histological examination of the tissues, the perforations were found to be very small with laser lithotripsy and considerably larger with the electrohydraulic lithotripsy. It was felt that laser lithotripsy in the clinical situation was likely to be much safer than electrohydraulic lithotripsy.

Animals↗
PubMed1992

Primary adenosquamous and squamous cell carcinoma of the colon and rectum.

Three new cases of squamous cell and adenosquamous carcinoma of the rectum are reported, bringing the total number of cases in the English medical literature to 72. Each of the three patients presented with painless hematochezia. Therapy was by surgical resection followed by chemoradiation therapy in two patients. The incidence, presentation, diagnostic criteria and methods, tumor location, natural history, theory of etiology and management of this unusual tumor are discussed.

Adenocarcinoma↗
PubMed1992

Postoperative T-tube tract choledochoscopy.

One hundred twenty-six patients underwent postoperative fiberoptic T-tube tract choledochoscopy for the management of retained biliary calculi as demonstrated by T-tube cholangiography. Extraction was successful in 94% of patients with retained stones. Thirty-nine patients had more than 1 stone, 20 patients had heptic duct stones, and 14 patients had large stones requiring electrohydraulic lithotripsy or laser fragmentation. Stone removal was not possible in six patients, secondary to either slippage of the T-tube with obliteration of the tract, inability to remove the stones with available instruments, a tortuous tract, or choledochoscope malfunction. Minor complications, most commonly transient fever, occurred in 12 patients. No serious complications or deaths occurred. The advantages of T-tube tract choledochoscopy include direct visualization of the biliary tree, avoidance of radiation exposure, and easy access to hepatic duct stones. This is the preferred method for treating retained biliary calculi in patients with a T-tube in situ.

Adult↗
PubMed1992

Biliary laser lithotripsy.

Laser lithotripsy is an excellent method of fragmenting those biliary stones that cannot be removed easily by less technically advanced methods such as basket extraction. The energy can be delivered through fine flexible fibers, around 200 to 320 microns in diameter, that can be passed through the channels of a variety of small endoscopes. Currently, the optimal laser seems to a pulsed system because of the conversion of light to acoustic energy with minimal heating of the surrounding tissues, thus avoiding the chance of tissue injury and perforation. The best wavelength seems to be 504 nm, because at this wavelength, there is maximum absorption of laser energy by pigment stones, resulting in fragmentation using low-energy pulses. With further research, optimal wavelengths and pulse durations may emerge.

Cholelithiasis↗
PubMed1992

Nutritional outcome and pneumonia in critical care patients randomized to gastric versus jejunal tube feedings. The Critical Care Research Team.

OBJECTIVE: To compare nutritional status, gastric colonization, and rates of nosocomial pneumonia in ICU patients randomized to gastric tube feeding vs. patients fed by an endoscopically placed jejunal tube. DESIGN: Randomized, prospective study. SETTING: Medical and surgical ICUs at Boston City Hospital; surgical ICU at University Hospital. PATIENTS: Of the 38 study patients, 19 were randomized to gastric tube feeding and 19 were randomized to an endoscopically placed jejunal tube. The two groups were similar in age, sex, race, underlying disease, and type of surgery. RESULTS: The two patient groups were similar in number of days fed, duration of ICU stay, duration of mechanical ventilation, days of antibiotic therapy, and days with fever. Compared with the gastric group, the jejunal group had more patients with circulatory shock on admission (79% vs. 68.4%), higher admission Acute Physiology Score (24.0 vs. 21.7), and fewer patients with pneumonia at randomization (26.3% vs. 31.6%). The jejunal group received a significantly higher percentage of their daily goal caloric intake (p = .05), and had greater increases in serum prealbumin concentrations (p < .05) than the patients with gastric tube feeding. Although the jejunal tube group had more days of diarrhea (3.3 +/- 6.6 vs. 1.8 +/- 2.9), this difference was not statistically significant. Nosocomial pneumonia was diagnosed clinically in two (10.5%) patients in the gastric tube group and in no patients in the jejunal tube group. CONCLUSIONS: Patients fed by jejunal tube received a significantly higher proportion of their daily goal caloric intake, had a significantly greater increase in serum prealbumin concentrations, and had a lower rate of pneumonia than patients fed by continuous gastric tube feeding.

Adult↗
PubMed1991

Gastrointestinal tract bleeding. Common dilemmas in management.

An accurate diagnosis is the prerequisite in defining gastrointestinal tract bleeding at any level. Flexible endoscopy is the mainstay of diagnosis, and, particularly in the colon, it may be used as a therapeutic tool in conjunction with fulguration. Radionuclide scanning and arteriography have a place in diagnosis when endoscopy fails. The management of variceal bleeding is, in the main, injection sclerotherapy, operation being reserved for patients who rebleed after injection sclerotherapy or in whom a long-term course of sclerotherapy fails. The management of patients with colonic bleeding depends on the accurate pinpointing of bleeding before operation followed by limited excision of the located bleeding site. Some sources of lower gastrointestinal-tract bleeding can be treated by therapeutic endoscopy.

Endoscopy, Gastrointestinal↗
PubMed1990

Electrohydraulic lithotripsy (EHL) for the treatment of large retained common duct stones.

Retained biliary stones may be too large for extraction through the existing T-tube tract. It may be necessary to dilate the tract, crush the stones or use endoscopic papillotomy. There are reports of stones and the extracting basket becoming stuck in the T-tube tract and tract ruptures caused by extracting large stones. In this study electrohydraulic lithotripsy (EHL) is used in combination with T-tube tract choledochoscopy for the fragmentation of large stones prior to basket extraction. T-tube choledochoscopy was performed under IV sedation and sterile conditions no sooner than one month following common bile duct exploration. The Olympus 4.9-mm choledochoscope was passed through the T-tube tract to visualize the stone. A #5 Fr EHL probe was passed through the endoscope and advanced to within 1 mm of the surface of the stone. EHL discharge was started at a low energy level being increased until the spark discharges caused stone fragmentation. The resultant stone fragments were basket extracted under direct vision. The procedure was used in twelve patients with removal of all stones in eleven patients. Eight patients were treated with one endoscopic session. Because of multiple stones, two patients required two sessions and one patient four sessions. In one patient stone position prevented adequate fragmentation and endoscopic papillotomy also failed. Repeat choledochoscopy and EHL were successful. There were no complications of EHL or choledochoscopy in any of the patients. EHL was both effective and safe for fragmentation of large common duct stones when performed under direct vision using a choledochoscope.

Endoscopy↗
PubMed1989

The use of lasers in the treatment of cholangiocarcinoma.

Six of seven patients were treated with external beam radiation, iridium-192 internal radiation and neodymium-YAG laser therapy via a percutaneous transhepatic tract for relief of biliary obstruction. After laser therapy, the transhepatic catheters were removed and patients remained tube-free and non-jaundiced for periods ranging from 1 to 20 months.

Adenoma, Bile Duct↗
PubMed1989

Response to Simko.

Explore the source record for details and available documents.

Esophageal Neoplasms↗
PubMed1988

Palliative laser therapy of advanced esophageal carcinoma: an alternative perspective.

Endoscopic Nd:YAG laser therapy was used on 91 occasions in 26 consecutive unselected patients with advanced malignant obstruction of the esophagus. Patients were treated predominantly by the retrograde method after initial esophageal dilatation. Laser therapy was effective in restoring esophageal luminal patency. However, luminal patency did not guarantee restoration of adequate oral nutritional intake. Twenty-seven percent of patients required additional nutritional support. Twenty-six percent of procedures were complicated by significant events, predominantly cardiorespiratory. Six deaths occurred within 30 days of laser therapy. Mean survival from time of first laser therapy was 16 wk. We conclude that laser therapy of malignant esophageal obstruction provides effective palliation of dysphasia; however, in older patients with advanced disease, this therapy often results in complications, as do other methods of treatment for this condition.

Adenocarcinoma↗
PubMed1988

Congenital duodenal diverticula: a report of three cases and a review of the literature.

Most duodenal diverticula are acquired, extraluminal, and false, but the congenital variety is rare, whether it is intraluminal or extraluminal. We present two cases of extraluminal congenital duodenal diverticula and one of the intraluminal type, and we also review the literature. The clinical presentation involves rather nonspecific abdominal symptoms, and most of these diverticula are incidental findings on upper gastrointestinal series. Duodenoscopy offers the best chance to diagnose the intraluminal diverticula. The complications and methods of treatment of each type of congenital duodenal diverticulum are discussed.

Adult↗
PubMed1987

Diversion colitis. Pathologic findings in a resected sigmoid colon and rectum.

We present here the detailed pathologic findings in the resected colon and rectum from a paraplegic patient with severely symptomatic diversion colitis and lack of anorectal function. Previous reports of the pathology of this condition have been confined to biopsy findings. A diffuse nodularity caused by lymphoid hyperplasia and an inflammatory process confined to the colorectal mucosa with erosions, crypt abscesses, mucin granulomas, and aphthoid ulcers were the main features. There was minimal distortion of crypt architecture. The pathologic features of this entity are compared to those of other inflammatory disorders of the colon and rectum.

Adult↗