Biomedical subjects

D C Brooks

Publications and source records attributed to D C Brooks.

At least 37 records · Page 2Linked to original sources

PubMed1994

Laparoscopic cholangiography. The case for a selective approach.

Intraoperative cholangiography has proved to be a significant benefit for the biliary surgeon by alleviating the morbidity of unnecessary common duct exploration in patients with suspected but unproved choledocholithiasis and by clarifying biliary anatomy in patients when dissection proves difficult. Laparoscopic surgeons should be capable of performing the procedure when indicated and should be comfortable interpreting the images obtained. Laparoscopic cholecystectomy with selective application of cholangiography can be performed with little or no effect on the incidence of retained calculi, with no impact on the incidence of common bile duct injury, and with diminished operative time and expense. The experienced laparoscopic surgeon can become facile with the procedure quickly and easily and does not require routine performance of the study to maintain these skills. Reduction of the incidence of biliary injury during laparoscopic cholecystectomy can be achieved by early meticulous dissection at the infundibular-cystic duct junction, with limited use of laser or electrocautery in this region rather than by reliance on intraoperative cholangiography.

Cholangiography↗

PubMed1993

Routine cholangiography is not warranted during laparoscopic cholecystectomy.

The role of intraoperative cholangiography during laparoscopic cholecystectomy was prospectively evaluated in 514 patients undergoing laparoscopic cholecystectomy. Before surgery, all patients were assigned to one of three groups depending on the likelihood of their having common bile duct stones. Stratification was based on objective historical, laboratory, or radiologic criteria. In 453 patients deemed unlikely to have stones, laparoscopic cholecystectomy was performed without cholangiography. Of these patients, four had retained stones (0.9%). In 25 patients likely to have stones, preoperative endoscopic retrograde cholangiopancreatography identified stones in six patients (24%). In 36 patients whose likelihood of having stones was deemed indeterminate, intraoperative cholangiography was performed at laparoscopic cholecystectomy. A common bile duct stone was identified in one patient (2.8%). One common bile duct injury occurred in the group deemed unlikely to have stones, and this injury would not have been prevented by intraoperative cholangiography. We conclude that preoperative assessment will identify common bile duct stones and that routine cholangiography is not warranted. Meticulous dissection of the cystic duct at its origin at the infundibulum will prevent common bile duct injury.

Adolescent↗

PubMed1993

Bile duct disruption after laparoscopic cholecystectomy.

The reported prevalence of biliary tract disruption following laparoscopic cholecystectomy has ranged from 0% to 7% in early reports. We have reviewed the first 823 laparoscopic cholecystectomies performed at our institution and found 13 symptomatic biliary complications necessitating further therapy (prevalence 1.6%). This finding represents a decrease from the 2.7% prevalence found in our earlier series. The incidence of biliary complications will likely continue to vary depending on patient selection, operator experience, and new developments in laparoscopic technique. Bile duct injury and bile leaks are often difficult to diagnose but must be strongly considered in postoperative patients with abdominal pain, fever, jaundice, or continued bilious drainage from a surgical drain. Whereas computed tomography (CT) and sonography are sensitive in detecting perihepatic or free peritoneal fluid collections, they are nonspecific and definitive diagnosis of biliary tract injury requires hepatobiliary scintigraphy, endoscopic retrograde cholangiopancreatography (ERCP), percutaneous transhepatic cholangiography (PTC), or percutaneous aspiration. Disruption of the biliary tree has commonly been treated with reoperation or percutaneous drainage. More recently, endoscopic management has shown encouraging results for bile leaks and strictures in small series.

Adult↗

PubMed1993

A retrieval cue for extinction attenuates spontaneous recovery.

Four experiments with rats in an appetitive conditioned magazine entry preparation examined spontaneous recovery after extinction. Spontaneous recovery was obtained 6 days but not 5 hr following extinction; recovery depended on the passage of time but not on the removal of a cue that was featured in extinction or on the reintroduction of early-session cues. A cue featured in extinction attenuated recovery when presented on the test. The attenuation effect depended on the cue's correlation with extinction; a cue featured in conditioning did not attenuate recovery. The extinction cue did not evoke responding on its own, suggesting that it was not a conditioned excitor. Retardation tests and a summation test did not reveal that it was a conditioned inhibitor. The cue might work by retrieving a memory of extinction. Spontaneous recovery thus occurs because the subject fails to retrieve an extinction memory. Other accounts of spontaneous recovery are discussed.

Animals↗

PubMed1993

Rapid development of umbilical metastases after laparoscopic cholecystectomy for unsuspected gallbladder carcinoma.

Unsuspected microscopic adenocarcinoma of the gallbladder was identified after operation in a 66-year-old woman undergoing elective laparoscopic cholecystectomy for symptomatic cholelithiasis. An abdominal wall metastasis developed at the periumbilical incision site through which the laparoscope was introduced and through which the gallbladder was removed. A review of the available information on tumor seeding of laparoscopic tracts and drain tracts is presented, as well as implications for the further management of gallbladder cancer and other intraabdominal malignancies.

Abdominal Neoplasms↗

PubMed1993

Effects of contextual conditioning and unconditional stimulus presentation on performance in appetitive conditioning.

Four experiments with rat subjects examined the effects of contextual conditioning on conditioned appetitive performance. Experiment 1 compared the effects of contextual conditioning on performance to conditioned stimuli (CSs) with different conditioning histories. Contextual conditioning enhanced performance to the CS if the CS had first been conditioned and then extinguished, but had no effect on performance when the CS had been merely paired or unpaired with food. Experiments 2 and 3 then asked whether the effect on the extinguished CS was due to contextual conditioning acting as a cue for conditioning. In Experiment 2, extinction procedures in which extra unconditioned stimuli (USs) were presented during the intertrial intervals were found to reduce the CS's sensitivity to enhancement by contextual conditioning, but had no effect on spontaneous recovery. In Experiment 3, USs added to conditioning or extinction acquired the ability to cue the corresponding performance. Under some conditions, USs added to conditioning could suppress performance (Experiment 4). The results suggest that contextual conditioning has complex effects that can be better understood by recognizing that contextual conditioning, as well as the USs that create it, may acquire discriminative control over conditioned responding.

Animals↗

PubMed1993

Failure of piezoelectric lithotripsy of a gallstone impacted in the gallbladder neck.

Failure of extracorporeal shockwave lithotripsy is most frequently related to total stone mass, the size of individual stones, or unrecognized stone calcification which interferes with the dissolution effects of orally administered bile salts. We report a case of piezoelectric extracorporeal shockwave lithotripsy failure in a young woman with a 2-cm stone impacted in the neck of the gallbladder. Despite adequate positioning of the shockwave focal point on two separate occasions, no fragmentation was achieved. The stone was subsequently retrieved after the woman underwent laparoscopic cholecystectomy. When treated ex vivo, the stone rapidly fragmented. We hypothesize that the impacted stone, lacking a uniform liquid interface, failed to fragment because of the inability of cavitational forces to achieve a surface effect.

Adult↗

PubMed1992

The use of a Doppler probe in laparoscopic surgery.

The use of a doppler probe, specially designed for use in laparoscopic surgery is described. The doppler probe is easy to use and fits through a 5 mm laparoscopic port. It facilitates the identification of vascular structures and has been an aid in performing laparoscopic varicocele ligations, pelvic lymph node dissections, and cholecystectomies.

Cholecystectomy↗

PubMed1992

A simplified technique for open laparoscopy using disposable trocars.

An easily accomplished method for performing open laparoscopy with disposable trocars is presented. This technique provides for safe entry into the peritoneum and subsequently facilitates removal of the gallbladder and any larger stones at the completion of the procedure.

Cholecystectomy, Laparoscopic↗

PubMed1992

Bile duct disruption and biloma after laparoscopic cholecystectomy: imaging evaluation.

Disruption of the biliary tree after laparoscopic cholecystectomy has been reported in 0-7% of cases, and likely represents the most significant postoperative complication. Documenting the presence and extent of a bile leak is often difficult. We reviewed the first 264 laparoscopic cholecystectomies performed at our institution and found seven cases of bile extravasation and/or biloma formation (prevalence, 2.7%). All patients were first seen in the early postoperative period with abdominal pain and low-grade fever. Sonography was performed in five of seven, CT in five of seven, hepatobiliary scintigraphy with diisopropyliminodiacetic acid in five of seven, and ERCP in four of seven cases. While sonography and CT were initially helpful in determining the presence of abdominal fluid collections, they were unable to differentiate between postoperative seroma, lymphocele, hematoma, and bile leak. Hepatobiliary scintigraphy was useful in demonstrating continuity of these fluid collections with the biliary tree and guiding further therapy. Four cases were managed with endoscopic biliary decompression, with the use of sphincterotomy or nasobiliary stent placement, with good clinical result. The other three cases were treated surgically with T-tube or external drainage. All patients did well clinically, without evidence of bile reaccumulation. Our experience suggests that sonography and CT are useful in detecting postoperative fluid collections, but cannot differentiate bile from other fluids. Hepatobiliary scintigraphy is valuable as a noninvasive means of investigating possible bile leaks and in guiding further therapy.

Adult↗

PubMed1992

The use of a Doppler probe to facilitate laparoscopic varicocele ligation.

The applications of laparoscopic techniques continue to expand. Laparoscopic varicocele ligation offers the potential to diminish postoperative morbidity for the patient. The addition of the laparoscopic Doppler probe enables the surgeon to perform a precise ligation of the gonadal veins while preserving the spermatic artery. Longer follow-up study will be required to accurately compare clinical efficacy and fertility rates after laparoscopic varicocele ligation with the traditional methods reported.

Equipment Design↗

PubMed1991

Laparoscopic cholecystectomy.

Laparoscopic cholecystectomy has emerged in the last 2 years as a unique procedure that offers the long-term advantages of open cholecystectomy without much of the short-term morbidity. Importantly, when compared with non-surgical approaches to symptomatic gallstones, it is suitable for virtually all patients rather than a highly-selected group as in the case of oral bile salt dissolution therapy or extracorporeal lithotripsy. Furthermore, it obviates the high recurrence rate seen with these techniques. Complications including bleeding and ductal injury appear to occur at a slightly higher rate than with traditional open cholecystectomy, but most surgeons who have had experience with the procedure predict that these complications will become rarer as more experience is gained. We may indeed be witnessing the first major successful challenge to traditional surgical management of symptomatic gallstone disease in 100 years.

Cholecystectomy↗

PubMed1991

Intraoperative use of a 2-mm choledochoscope for the exploration of small bile ducts and the pancreatic duct.

Intraoperative visualization of the biliary and pancreatic ducts can be difficult in a nondilated system. Very small extra- and intrahepatic bile ducts occasionally require visualization but do not admit the traditional 6.5-mm intraoperative flexible choledochoscope. We have prospectively examined the use of a 2-mm choledochoscope for the intraoperative evaluation of the biliary and pancreatic ducts in 36 patients. In 27 patients, the choledochoscope was advanced through the cystic duct stump for examination of the common bile duct following cholangiography. The scope was successfully passed into the cystic duct stump and into the common bile duct in 76 per cent of patients. Inability to pass the scope through the cystic duct was usually due to acute angulation of the cystic duct/common duct junction. In an additional five patients, intraoperative cholangiography revealed a filling defect in a very small duct. A choledochotomy was made and the 2-mm choledochoscope was used to exclude the presence of stones in a small bile duct. In four patients the choledochoscope was used during a Puestow procedure to visualize and help extract stones in the tail and head of the gland. No complications occurred in these patients due to the use of the choledochoscope. We conclude that the 2-mm choledochoscope aids in internal visualization of small intra- and extrahepatic bile ducts and the pancreatic duct. It may be useful as an adjunct to cholangiography in determining the nature of filling defects.

Bile Duct Diseases↗

PubMed1990

100 consecutive common duct explorations without mortality.

It has been suggested that the incidence of morbidity and mortality after common duct exploration no longer justifies its use in patients with a gallbladder in situ. Therefore endoscopic sphincterotomy has been advocated for removal of common duct stones before cholecystectomy in selected patients. The purpose of this study was to determine our current rate of retained common duct stones and the morbidity and mortality rates associated with common duct exploration. Charts of 100 consecutive patients who underwent cholecystectomy and common duct exploration from January 1982 through December 1986 were reviewed. Indications for duct exploration included jaundice, dilated common bile duct, gallstone pancreatitis, multiple small stones, and abnormal intraoperative cholangiogram. Common duct exploration was done by manual technique or choledochoscopy, as determined by the surgeon's preference. Only two patients required duodenotomy for extraction of difficult stones. There were no deaths in this series of consecutive common duct exploration. The total morbidity rate was 15.7%, which included a 5.3% incidence of retained common duct stones. There was a 7.4% major complication rate, including deep vein thrombosis, bleeding gastric ulcer, and pneumonia. The remaining complications were minor and did not prolong hospitalization. There was one wound infection and no postoperative pancreatitis. None of the complications were directly attributable to choledochotomy or duct exploration. All retained common duct stones were removed by endoscopic retrograde cholangiopancreatography or by angiographic basket and did not require reoperation. It is concluded that operative common duct exploration not requiring duodenotomy is safe and does not appreciably increase the incidence of complications after cholecystectomy. Endoscopic sphincterotomy continues to be the preferable alternative to operative common duct exploration for patients with retained common duct stones.

Cholangiopancreatography, Endoscopic Retrograde↗

PubMed1989

Total pancreatectomy for ductal cell carcinoma of the pancreas. An update.

Forty-eight patients with ductal cell carcinoma of the pancreas underwent total pancreatectomy. During 1970-1976, there were four deaths (a mortality of 18%). During the last twenty-eight operations (1977-1986), there were no hospital deaths. Seventeen per cent of the patients suffered intraoperative complications involving the mesenteric vessels. Twenty-seven per cent suffered postoperative complications. Twenty-five per cent of the patients left the hospital within 2 weeks, 50% left within 4 weeks, and another 25% remained in the hospital for longer than 4 weeks. Thirty-five per cent of the patients have returned to their preoperative job or similar life activity. Another 35% were able to lead an active life but did not return to regular work, and 30% were to some degree incapacitated by their operative procedure and disease. Twenty-one per cent of the patients lived for 4 years, and 14% survived for 5 years.

Adult↗

PubMed1988

High-resolution real-time ultrasonography. A new tool in the diagnosis of acute appendicitis.

A prospective study was performed to assess the sensitivity and specificity of ultrasonographic evaluation in 44 patients with suspected appendicitis. We found ultrasonographic evaluation to have a sensitivity rate of 89 percent, a specificity rate of 86 percent, and an overall accuracy rate of 87 percent. These results are very similar to those in other recently reported studies. We also identified certain patients in whom nondiagnostic studies are likely. Our results suggest that ultrasonographic evaluation may be of particular use in selected patients who do not demonstrate the classical signs and symptoms of acute appendicitis.

Acute Disease↗

PubMed1988

Surgical therapy for thyroid carcinoma: a review of 1249 solitary thyroid nodules.

A total of 1249 "cold" solitary thyroid nodules were excised at the Brigham and Women's Hospital from 1948 through 1987. Of these nodules, 241 showed malignant conditions: 123 were papillary, 42 were mixed papillary-follicular, and 43 were pure follicular carcinomas. There were also 23 anaplastic, 8 medullary, and 3 Hürthle cell carcinomas. These patients were followed up from 3 to 31 years, with a mean range of 10 years. Fifty-three patients with well-differentiated tumors underwent total thyroidectomies, and 179 underwent subtotal thyroidectomies (excluding anaplastic, medullary, and Hürthle cell tumors). Regional lymph node involvement was commonly found but appeared not to affect survival; tumor size and local spread and extent of thyroid gland involvement did affect survival. A small percentage of well-differentiated thyroid tumors do, in time, undergo anaplastic change that leads to metastasis and death. There was no 30-day mortality rate. The late mortality rate was 2% for papillary and 14% for follicular carcinomas. Papillary tumors are becoming more common. Older aged patients and male patients appear to carry poorer prognoses for survival. The total thyroidectomy procedure has not improved survival over subtotal thyroidectomy and carries a higher complication rate.

Adenocarcinoma↗

PubMed1988

Chronic pancreatitis secondary to an inflammatory polyp of the duodenum 25 years after Billroth II reconstruction.

A 51-year-old man, 25 years after undergoing Billroth II gastrojejunostomy with antrectomy and vagotomy, came to our hospital with acute relapsing pancreatitis. At operation he was found to have an inflammatory polypoid lesion at the duodenal stump that consisted of suture and talc granuloma from his previous gastric surgery. The polyp intermittently obstructed the pancreatic duct, causing symptomatic pancreatitis. The patient has remained without symptoms 2 years after submucosal resection of this polyp. This complication of Billroth II gastroenterostomy has not been recognized previously.

Chronic Disease↗