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Biomedical subjects

S W Unger

Publications and source records attributed to S W Unger.

At least 19 recordsLinked to original sources
PubMed2000

Microlaparoscopic cholecystectomy. Less invasive gallbladder surgery.

BACKGROUND: We set out to compare a prospective evaluation of microlaparoscopic cholesystectomy (MLC) using 5-mm ports for the scope and operating ports and two 2-mm ports for retracting to the historic results of standard laparoscopic cholecystectomy (SLC). METHODS: Fifty-six consecutive patients were operated electively for symptomatic gallstones between June 1997 and July 1998. Demographics, history of prior abdominal surgery, operative time, resident level, need to convert, length of stay, and postoperative analgesia were recorded for each case. In all, 43 women and 13 men aged 21 to 89 (average, 51 years) underwent MLC. Average weight was 78 kg (range, 48-119) and average height was 163 cm. RESULTS: Operative time for MLC was 72+/-25 min (range, 35-140), somewhat less than the referenced standard of 79+/-27 min (p = 0.1). The skin-to-trocar time (6+/-2 vs. 13+/-77 min) and intraoperative cholangiogram time (9+/-8 vs. 11+/-6 min) were significantly shorter (p<0.01 and p<0.05, respectively) for MLC. Other partial times were not significantly different. PGY2 residents averaged 74+/-21 min (range, 44-118) compared to 75+/-27 min (range, 35-140) for PGY3 and 53+/-5 (range, 43-59) for PGY5. Patient weight influenced time. Patients <65 kg averaged 56 +/-12 min; 66-80 kg, 72+/-24 min; 81-95 kg, 78+/-26 min; and >95 kg, 85+/-22 min. Previous abdominal surgery did not affect operative time. Nine patients (16%) required conversion from 2- to 5-mm ports because of adhesions, wall thickening, or need for better retraction. Time in these patients was 95+/-26 min vs. 68+/-21 min in other patients (p<0.01). No patient was converted to an open procedure. Three patients (5%) had a positive cholangiogram and common bile duct exploration that required placement of an extra 5-mm trocar. Five patients (9%) required insertion of an additional 2-mm port. All patients received patient-controlled analgesia (PCA). Morphine use was 0.21+/-0.19 mg/kg (range, 0-0.8). Hospital stay was 1.31 days (range, 0.5-4). Subjective satisfaction was excellent because of smaller incisions. No additional morbidity was seen with MLC. CONCLUSION: MLC is a feasible and safe approach that provides similar times to SLC with better cosmesis, a less painful recovery, and possibly an earlier return to normal activity.

Adult↗
PubMed1998

Smaller is better.

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Cholecystectomy, Laparoscopic↗
PubMed1998

Metabolic fluctuation during a muscle contraction cycle.

Gated 31P-nuclear magnetic resonance followed the metabolic fluctuation in rat gastrocnemius muscle during a contraction cycle. Within 16 ms after stimulation, the phosphocreatine (PCr) level drops 11.3% from its reference state. The PCr minimum corresponds closely to the time of maximum force contraction. Pi increases stoichiometrically, while ATP remains constant. During a twitch, PCr hydrolysis produces 3.1 mumol ATP/g tissue, which is substantially higher than the reported 0.3 mumol ATP.twitch-1.g tissue-1 derived from steady-state experiments. The results reveal that a substantial energy fluctuation accompanies a muscle twitch.

Adenosine Triphosphate↗
PubMed1997

Standardizing laparoscopic procedure time and determining the effect of patient age/gender and presence or absence of surgical residents during operation. A prospective multicenter trial.

BACKGROUND: Most of the expense of laparoscopic cholecystectomy (LC) is incurred while the patient is in the operating room (OR). Half of this operating room cost is equipment and the other half is personnel. What is an acceptable LC procedure time and how much variation is there? What are the effects of age, gender, and expertise on the mean LC procedure time? METHODS: A prospective, multicenter gathering of LC procedure times and task component times was performed through the cooperative effort of members of the Society of American Gastrointestinal Endoscopic Surgeons (SAGES) at 11 hospitals. The effect of LC time of age, gender, and surgical resident was recorded. RESULTS: The mean LC time for 359 cases was 73 +/- 28 min. The percent of this LC time for the following component tasks included: to place and remove trocars, 34%; total dissection time, 40%; intraoperative cholangiogram, 15%; and removing the gallbladder, 7%. Age and gender did not change LC time, but the presence of a surgical resident prolonged LC time from 53 to 79 min due to an increase in all LC component task times. CONCLUSIONS: LC time was globally calibrated in 11 North American hospitals and was found to be affected by expertise but not by gender or age. The mean and standard deviation of LC time can be used for purposes of self-assessing quality performance.

Age Factors↗
PubMed1997

Laparoscopic cholecystectomy in the elderly.

BACKGROUND: Advanced age with its concomitant comorbid conditions may be associated with increased postoperative laparoscsopic cholecystectomy (LC) complications and more frequent conversion to open cholecystectomy (OC). The purpose of this study was to evaluate the outcome of LC in patients age 65 and older. METHODS: Ninety consecutive patients were studied age 65 and older, of whom 39 (43%) were males and 51 (57%) were females, mean age 74 years (range 65-98), with 20 patients (22%) >/= 80. Indications for surgery included biliary colic 55 (61%), acute cholecystitis 22 (24%), pancreatitis 10 (11%), and cholangitis 3 (4%). Seventeen patients (19%) had preoperative ERCP, 12 of which were normal; five had sphincterotomy with stone extraction. Comorbid conditions included hypertension (44%), CAD (17%), cardiac arrhythmias (18), CHF (9%), and COPD (7%). RESULTS: Operative time-mean 1 h 51 min +/- SD 43 min. Conversion to OC-three patients (3%). Length of stay-mean 5 days (range 1-26). Mortality-two patients (2%) >80 years old, one patient with septicemia and multiorgan failure whose comorbid diseases included CAD, C.F., COPPED, and elevated BP, one patient with MI postsurgery, morbid diseases included DM and CAD. Complications-five patients (5%): bile leak from cystic duct stump (one), postsurgery MI (two), incarcerated incisional hernia (one), septicemia (one). CONCLUSION: Morbidity rates for LC in the elderly population are not different from that reported for patients less than 65 years of age. (5% vs 6%, Fried et al., Surg Clin North Am 1994;74 [2]: 375-387). Our 2% mortality rate is statistically different from previously reported in a series of patients of all ages (0.6%, Fried et al.). The 3% rate of conversion to OC in this older population is not significantly different from the patients in Fried et al. series (4%).

Acute Disease↗
PubMed1995

Bipolar versus monopolar cautery scissors for laparoscopic cholecystectomy: a randomized, prospective study.

The most efficacious energy source for laparoscopic surgery is constantly being debated. Monopolar electrocautery has gained wide popularity over laser energy because of its lower cost and ease of use. Bipolar current has been extensively used by gynecologists for peritoneoscopic surgery after reports of injuries from monopolar current. The purpose of this study was to compare bipolar scissors (Evershears, Everest Medical) and monopolar scissors (Endoshears, United States Surgical Corporation). Eighty patients were prospectively randomized as to the type of scissors to be used for dissection of the gallbladder from the liver bed during laparoscopic cholecystectomy. The scissors were evaluated subjectively with regard to cutting, coagulation, char, and smoke. The two groups were similar in age, sex, weight, blood loss, and hospital stay. Cutting ability and charring were equal. Coagulation was superior in the monopolar group. Smoke was much less with bipolar energy. Overall satisfaction was similar. We concluded that bipolar scissors are a good, safe device for dissection of the gallbladder from the liver bed during laparoscopic cholecystectomy and compare favorably with monopolar scissors.

Adult↗
PubMed1994

AESOP robotic arm.

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General Surgery↗
PubMed1994

Laparoscopic gastrostomy versus percutaneous endoscopic gastrostomy. A comparison.

A retrospective study was carried out at our institution to compare patients who underwent percutaneous endoscopic gastrostomy (PEG) to those who underwent laparoscopic gastrostomy (LG). There were 17 patients who had a PEG with a mean age of 81 years (43-97 years). The procedure time, including complete esophago-gastroduodenoscopy, averaged 28 min. There were four deaths (23%) in a 30-day period, but none of these were directly related to the procedure. The LG group consisted of 14 patients with a mean age of 66 years (20-94 years). Mean duration of the procedure was 18 minutes. Thirty-day mortality rate was 35% (five patients) with one death (7%) directly related to the tube. Indications for gastrostomy were similar in both groups, being predominantly inability to eat and/or recurrent aspiration. However, LG was done because of 4 technical failures, 5 patients with tumors of the head and neck, 2 patients with esophageal obstruction and radiation stenosis precluding safe PEG, and 1 patient with hiatal hernia; 2 LGs were performed at the surgeon's preference. Outcomes for LG and PEG were comparable. LG is a suitable, safe alternative to PEG in selected patients who cannot undergo gastroscopy and should be considered the procedure of choice in patients with head and neck tumors or intrathoracic pathology that prevents PEG.

Adult↗
PubMed1994

Laparoscopic surgery: surgical education in the People's Republic of China.

In 1991, because of the international emphasis on laparoscopic surgery, a large contingency of surgeons took on the task of introducing laparoscopy to the People's Republic of China. This trip was a technological feat, since all of the equipment and instrumentation had to be carried into the country. This necessitated a major coordinated effort among professional teaching staff and industry representatives with their transported equipment. This unique educational opportunity is detailed in this article, which highlights, in particular, the contrast between the new "high-tech" surgery and the reality of a developing country.

China↗
PubMed1994

Laparoscopic gastrostomy and jejunostomy: review of 22 cases.

Laparoscopic gastrostomy (LG) and laparoscopic jejunostomy (LJ) were performed successfully on 22 consecutive patients after development of the procedure on a porcine model. Patients did not undergo percutaneous endoscopic gastrostomies (PEG) due to obstruction from head and neck, esophageal cancer, gastropexy for gastric volvulus, perforated esophagus, failed PEGs, or surgeon's preference. Operative time averaged < 20.5 min. Five patients underwent the procedure under local anesthesia with intravenous sedation and three patients were operated on in a strictly outpatient setting. There was one postoperative death. LG and LJ are safe alternatives to open enterostomy in patients who cannot undergo PEG.

Adult↗
PubMed1992

Resident education in surgical endoscopy.

Under the auspices of the Resident Education Committee of the Society of American Gastrointestinal Endoscopic Surgeons, 158 of 298 (53%) of surgical training program directors responded to a survey on the current status of endoscopy in residency programs. Although 100 per cent claim that gastrointestinal endoscopy is provided by their program, only 76 per cent have formal endoscopy training, usually centered around the PGY 3 level, with only 23 per cent having didactic lectures in endoscopy. Directors claim to have trained nearly all of their residents by the completion of residency, averaging 44 esophagogastroscopies, 37 colonoscopies, and 46 flexible sigmoidoscopies per resident. However, they feel only 71 per cent of trainees are able to perform esophagogastroscopies and 67 per cent to perform colonoscopies in clinical practice. Ninety-seven per cent of directors feel endoscopy is important to surgical residency training, and 87 per cent have full-time faculty doing endoscopy. Only 44 per cent have a director of endoscopy; endoscopy is supervised by surgeons exclusively in only 48 per cent. Only 35 per cent have ongoing endoscopy research. When surgeons are not performing endoscopy, 66 per cent feel that the gastrointestinal (GI) service provides adequate service or training. Gastroenterology has a monopoly in endoscopy at 28 per cent of institutions, and 67 per cent of program directors feel there would be resistance to the formation of a separate surgical endoscopy service. Surgeons work in their own surgical endoscopy suite in only 15 per cent of institutions; in a GI suite in 13 per cent; and in a combined suite in the remainder.(ABSTRACT TRUNCATED AT 250 WORDS)

Attitude of Health Personnel↗
PubMed1991

Proton nuclear magnetic resonance study of the solution distal histidine orientation in monomeric Chironomus thummi thummi cyanomet hemoglobins. Dynamic stability of the heme pocket as monitored by labile proton exchange.

The 1H nuclear magnetic resonance spectral characteristics of the cyano-Met form of Chironomus thummi thummi monomeric hemoglobins I, III and IV in 1H2O solvent are reported. A set of four exchangeable hyperfine-shifted resonances is found for each of the two heme-insertion isomers in the hyperfine-shifted region downfield of ten parts per million. An analysis of relaxation, exchange rates and nuclear Overhauser effects leads to assignments for all these resonances to histidine F8 and the side-chains of histidine E7 and arginine FG3. It is evident that in aqueous solution, the side-chain from histidine E7 does not occupy two orientations, as found for the solid state, rather the histidine E7 side-chain adopts a conformation similar to that of sperm whale myoglobin or hemoglobin A, oriented into the heme pocket and in contact with the bound ligand. Evidence is presented to show that the allosteric transition in the Chironomus thummi thummi hemoglobins arises from the "trans effect". An analysis of the exchange with bulk solvent of the assigned histidine E7 labile proton confirms that the group is completely buried within the heme pocket in a manner similar to that found for sperm whale cyano-Met myoglobin, and that the transient exposure to solvent is no more likely than in mammalian myoglobins with the "normal" distal histidine orientation. Finally, a comparison of solvent access to the heme pocket of the three monomeric C. thummi thummi hemoglobins, as measured from proton exchange rates of heme pocket protons, is made and correlated to binding studies with the diffusible small molecules such as O2.

Animals↗
PubMed1991

Laparoscopic approach to gallstones in the morbidly obese patient.

Obesity has been suggested to be a contraindication to laparoscopic cholecystectomy (LC). In our center, in which all patients presenting with symptomatic gallstones are considered to be candidates for LC, 24 of the first 325 LC candidates were retrospectively found to be morbidly obese. In all, 20 were women and 4 were men. The average age was 51 years (range 32 to 83 years); the average height and weight amounted to 72 inches and 298 pounds, respectively, for men; and 63.5 inches and 258 pounds, respectively, for women. One-third of these patients suffered from acute cholecystitis, and more than 50% had undergone prior abdominal surgery. The average duration of LC in these subjects was 114 min., which was 25% longer than that in nonobese patients. The average length of the hospital stay was 1.6 days, with patients returning to normal activities within an average of 6.5 days. There was no major morbidity and no mortality. Since obese patients tolerated LC as easily as did normal patients, we concluded that obesity is an indication rather than a contraindication to LC.

Adult↗
PubMed1991

Laparoscopic treatment of acute cholecystitis.

Retrospective review of the first 210 patients treated by laparoscopic cholecystectomy revealed 55 patients (26%) with acute cholecystitis diagnosed preoperatively or intraoperatively. Average age was 52 years amongst 38 women and 17 men. Cardiac history was present in 4%, pulmonary disease was noted in 9%, and other significant medical history was found in 10%. Abnormal preoperative laboratory values (white blood cell count, liver function) were seen in 80%. Operations averaged 104 minutes. Dissection was performed with the potassium titanyl phosphate (KTP) laser in 9%, neodymium-doped yttrium aluminum garnet (Nd Yag) laser in 20%, and electrocautery alone in 71%. Average body habitus was 5 ft 9 in, 178 lb for men and 5 ft 5 in, 155 lb for women. Average length of stay was 2.6 days. Thirty-eight patients (69%) left the hospital in < 2 days. Postoperative complications included one case each of urinary retention, pneumonia, myocardial infarction, and three cases of postoperative fever. Drains were placed in 10 patients (18%). There was no mortality. Suggestions are made for technical considerations that make laparoscopic cholecystectomy a safe and efficient approach to acute cholecystitis.

Acute Disease↗