Small optic suspensions for Advanced LIGO input optics and other precision optical experiments.

We report on the design and performance of small optic suspensions developed to suppress seismic motion of out-of-cavity optics in the input optics subsystem of the Advanced Laser Interferometer Gravitational Wave Observatory. These compact single stage suspensions provide isolation in all six degrees of freedom of the optic, local sensing and actuation in three of them, and passive damping for the other three.

Intravenous cholangiography in the rhesus monkey. part I: Determination of optimal iodipamide dose during a one-hour infusion.

One-hour infusion intravenous cholangiography with iodipamide was performed in 3 rhesus monkeys with intact enterohepatic circulations. A series of four different doses including standard (0.3 ml/kg) and "double dose" (0.6 ml/kg) levels were compared. The 0.6 ml/kg dose resulted in significantly higher biliary iodine excretion and concentration than the lower two doses. A 1.2 ml/kg dose probably increased biliary iodine concentration a small amount when compared to the 0.6 ml/kg dose but did not increase iodine excretion. Peak iodine excretion and concentration occurred, on the average, at one hour. The excretion of iodine in the bile demonstrated no inhibitory effect on the concomitant excretion of bile salts.

Increases in gallbladder prostaglandin synthesis before the formation of cholesterol gallstones.

Increased synthesis of prostaglandins in the wall of the gallbladder may play a role in the pathogenesis of cholesterol gallstones by mediating mucus hypersecretion and thereby accelerating nucleation and the precipitation of cholesterol-supersaturated bile. We induced gallstones in prairie dogs and guinea pigs by feeding a cholesterol-supplemented diet for periods as long as 6 weeks. Gallbladder prostaglandin synthesis was quantitated by specific radioimmunoassays that measured the amount of various prostanoids released from the gallbladder during in vitro incubation. The gallbladders of cholesterol-fed prairie dogs showed increased synthesis of prostaglandin E2, prostaglandin F2a, and thromboxane and increased concentrations of glycoprotein in gallbladder bile. These changes were evident as early as 2 weeks after institution of the cholesterol diet, although cholesterol gallstones did not form until 4 or more weeks. In contrast, cholesterol feeding of the guinea pig did not induce cholesterol supersaturation. In this species pigment gallstones formed, probably as a result of a cholesterol-induced hemolytic anemia, and gallbladder mucus hypersecretion did not occur. Pigment gallstone formation in the guinea pig was associated with an increase in prostacyclin synthesis, but the synthesis of prostaglandin F2a and thromboxane was decreased. Increased prostaglandin synthesis may contribute to the formation of cholesterol gallstones but does not appear to participate in pigment gallstone formation.

Amino acid clearance and prognosis in surgical patients with cirrhosis.

To measure the effects of cirrhosis on amino acid (AA) flux and to assess the value of the central plasma clearance rate of amino acids (CPCR-AA) as a hepatocyte function test, 35 patients with cirrhosis were studied before and after operation. Fourteen of these patients died after the operation. CPCR-AA measures the number of milliliters of plasma cleared of AA per minute by the liver and other visceral tissues. It is the ratio of AA entry rate into plasma (from peripheral tissues plus infusion) to the arterial AA plasma concentration. Preoperative CPCR-AA measurements in 21 fasted patients with cirrhosis who were not infected revealed a pattern of AA plasma concentration and exchange similar to that previously observed in patients with sepsis with normal liver function. Whereas the concentration of AA in both groups was slightly lower than normal, the CPCR-AA of each was more than four times that of normal postabsorptive people (p less than 0.01). However, preoperative values of CPCR-AA in patients with cirrhosis who survived was 220 +/- 26 ml/M2/min while that in those who died was 97 +/- 16 ml/M2/min (p less than 0.001). Postoperative measurements remained relatively unchanged: survivors 212 +/- 24 ml/M2/min and those who died 89 ml/M2/min (p less than 0.0005). Measurements in vitro of the hepatic protein synthetic rate in liver biopsy specimens taken at operation correlated well with CPCR-AA values obtained immediately before operation in 10 patients (r = 0.73; p less than 0.01). Thus in patients with cirrhosis visceral amino acid uptake and hepatic protein synthesis are maximally stimulated. Nevertheless, if the preoperative CPCR-AA does not approach the value of 284 +/- 76 ml/M2/min previously observed in patients with sepsis who recover, the patient with cirrhosis is prone postoperatively to die of overwhelming infection and multisystem failure.

Pancreatoduodenectomy with pyloric preservation for carcinoma of the pancreas: a cautionary note.

Radical pancreatoduodenectomy for treatment of pancreatic carcinoma has been the surgical standard of care for the past four decades. The recent popularization of pylorus-sparing pancreatoduodenectomy to treat benign pancreatic disease, because of its decreased morbidity and long-term nutritional consequences, has led to the use of this procedure in cases of pancreatic carcinoma. We report recent experience with three patients with pancreatic carcinoma in whom pyloric preservation would have compromised the potential chance for curative resection or compromised palliation because of occult spread of tumor to a region not resected with this new operative approach. Two patients had proximal, microscopic intramural spread of pancreatic adenocarcinoma within the duodenum or antrum--a mode of spread not previously reported with pancreatic carcinoma. Both patients had no other evidence of metastatic involvement, and both would have had positive surgical margins in a pylorus-sparing pancreatoduodenectomy. A third case demonstrates a true submucosal recurrence of pancreatic carcinoma after a pylorus-sparing pancreatoduodenectomy. It is debatable that any case demonstrating intramural spread within the duodenum could be cured with a standard Whipple resection as this may well represent another sign of incurability, like lymphatic or perineural spread, but it is clearly a major potential obstacle to palliation if submucosal recurrences occur as a result of the use of the pylorus-sparing pancreatoduodenectomy in cases of pancreatic cancer. The use of pylorus-sparing pancreatoduodenectomy in resectable pancreatic cancers must be viewed skeptically at this time.

Changes in gallbladder volume do not affect cystic duct resistance.

To our knowledge, the relationship between gallbladder volume and cystic duct function has not been studied. We hypothesized that changes in gallbladder volume would influence cystic duct resistance. The effect of gallbladder volume changes on cystic duct resistance to both prograde (emptying) and retrograde (filling) steady-state flow was tested in 12 dogs under basal cholecystokinin-stimulated conditions utilizing a multiport catheter with a highly compliant balloon placed within the gallbladder fundus. Gallbladder volume was regulated by varying balloon volume from empty to just beyond physiologic distention. Cystic duct resistance was not affected by balloon volume under basal or stimulated conditions or by the direction of perfusate flow. This study demonstrated no relationship between gallbladder volume and cystic duct resistance and did not demonstrate a cystic duct sphincter mechanism at physiologic gallbladder volumes.

Choledochoscopic removal of retained stones via a T-tube tract.

Common duct stones retained after choledocholithotomy were removed in 11 patients under intravenous sedation using the Olympus fiberoptic choledochoscope passed through a T-tube tract. A total of 39 stones were removed during 12 procedures, with one patient requiring 2 procedures for complete stone removal. All common duct stones were removed, with no patient requiring further operation or procedures for stone removal. The complication rate was low; one patient had pancreatitis and four patients had a transient fever 8 to 12 hours after the procedure. Direct visualization proved an advantage in stone removal, and the patients were not exposed to the radiation required by the fluoroscopic method of stone extraction.

Is pulmonary angiography essential for the diagnosis of acute pulmonary embolism?

The records of 158 patients who underwent pulmonary angiography for the presumed diagnosis of acute pulmonary embolism were retrospectively reviewed. Of the 111 patients in the category of high probability for pulmonary embolism based on clinical impression, 60 patients (54 per cent) had a positive pulmonary angiogram. Of the forty-seven patients in the low probability group, ten (21 per cent) had a positive angiogram. Forty-eight of the seventy-three patients (66 per cent) with a high probability lung scan had a positive pulmonary angiogram. Eleven of twelve patients (92 per cent) with a high probability ventilation-perfusion scan had a positive pulmonary angiogram, and two of eight patients (25 per cent) with a low probability ventilation-perfusion scan had a positive pulmonary angiogram. The mean PO2 of patients with a positive pulmonary angiogram was 64 mm Hg, and the mean PCO2 30 mm Hg. The mean PO2 of patients with a negative pulmonary angiogram was 63 mm Hg and the mean PCO2 34 mm Hg. Based on these data, we believe that the accuracy of pulmonary angiography in diagnosing acute pulmonary embolism is much higher than that of the clinical impression, arterial blood gas determinations, and lung scanning technics.

A new treatment of ischemic bowel disease: steroid delivery via retrograde venous route.

The present therapeutic approach to occlusive mesenteric disease is unable to alter its high mortality and morbidity. We attempted to stabilize the intestinal lysosomal population with steroid prior to revascularization and thus reduce the lysosomal effluent. Steroid delivery during the occlusive period was accomplished via retrograde venous flow in the portal system. During revascularization steroid was further infused via the superior mesenteric artery. Our experimental model compared systemic venous delivery with retrograde portal venous delivery of steroid. Analysis of tissue acid phosphatase levels suggested steroid delivery via retrograde portal venous flow is the most efficient method of lysosomal stabilization.

Principles of biliary extracorporeal lithotripsy. Technical considerations and clinical implications.

After recent reports of the successful use of extracorporeal shock-wave lithotripsy for the treatment of gallstone disease, at least 10 different manufacturers have developed lithotripsy systems and initiated clinical trials in the United States. The three major types of lithotripters, classified by the method used to generate shock waves, are the spark-gap, piezoelectric, and electromagnetic systems. Although each type of system generates shock waves by different methods, all currently available systems appear to be able to fragment gallstones. However, there does not appear to be any system that has demonstrated clear clinical superiority in terms of either efficacy or safety. Additional information, both clinical and experimental, is needed before it can be determined if the type of shock-wave generator has a significant effect on outcome. Clearly more than the physical principles of shock-wave lithotripters must be evaluated.

Retrocecal appendicitis.

The clinical presentation of 105 cases of retrocecal appendicitis was reviewed. Thirty-six percent of the patients had the classic appendicitis scenario of periumbilical pain localizing to the right lower quadrant, accompanied by anorexia, nausea and vomiting, and tenderness and guarding in the right lower quadrant. The remaining 64 percent had subtle variations of this presentation. Retrocecal appendicitis did not have a distinctive clinical pattern in our series. Twelve of the 105 retrocecal appendices were also retroperitoneal. The diagnosis was delayed in four patients and two had flank pain. Five of the twelve appendices were either gangrenous or perforated. Although the number of patients is small, we conclude that the traditional type of retrocecal appendicitis can occur in the retroperitoneal subgroup but that his anatomic variation is infrequent. The incidence in our series was 2.5 percent.

Gunshot wounds of the left upper abdominal quadrant associated with multiple intraabdominal injuries.

This study reviews low velocity gunshot wounds of the left upper quadrant of the abdomen and presents four cases recently treated at Boston City Hospital. All patients sustained multiple intraabdominal organ injuries and underwent prompt exploration. Hypotension on admission seemed to be the most reliable sign for a prolonged and complicated hospital course. The essential preoperative studies in stable patients should include a chest x-ray and intravenous pyelogram. Intraoperatively, injury to the body or tail or the pancreas is best managed by distal pancreatectomy and sump drainage. Exploration of the retroperitoneum is warranted for bleeding from the kidney. Initial maneuvers should be designed to control hemorrhage from the renal pedicle. If this is unsuccessful or the renal parenchyma is badly fragmented, nephrectomy should be performed. The complications noted in our patients, infection (pneumonia and left subphrenic abscess) and hemorrhage, are comparable to those reported in most large series. Pancreatic complications (fistulas, pseudocysts, and pancreatitis) were not noted.

Intraabdominal sepsis after hepatic trauma.

In a review of 58 patients who survived liver trauma seen at Boston City Hospital, 10 patients had 13 intraabdominal abscesses and 1 died from overwhelming sepsis. Multivariate analysis of risk factors revealed that the number of units of perioperative, postoperative, and total blood transfused were each highly significant (p less than 0.0001). Mode of injury, hepatic resection, gastrointestinal tract perforation, and the number of associated injuries were not significant risk factors when transfusion requirements were accounted for. Fever and leukocytosis were unreliable predictors of abscess formation. The available literature suggests a strong relationship between intraperitoneal bleeding and septic complications.

Lower gastrointestinal bleeding. Diagnostic approach and management conclusions.

The management of patients with lower gastrointestinal bleeding requires a systematic approach based on defined diagnostic and therapeutic methods. Although in 80 percent of patients bleeding will stop spontaneously, 25 percent will have rebleeding and 50 percent of those with rebleeding will bleed again. Angiography documents specific bleeding sites but raises questions related to the incidence, site and frequency of bleeding, as well as the necessity of demonstrating extravasation. We reviewed 49 arteriograms performed for lower gastrointestinal bleeding. We conclude from our findings that angiography identifies a presumptive cause of bleeding in 49 percent of patients; angiography identified the site of bleeding in 86 percent of the patients with active bleeding, thus allowing segmental colectomy. We believe that documentation of angiodysplasia in a patient with lower gastrointestinal bleeding is presumptive evidence for the site of bleeding. Angiography is useful and worthwhile in the work-up of patients with lower gastrointestinal bleeding in an attempt to plan localized, definitive resection, and this may lead to a lower mortality rate.

New approaches to the management of severe acute pancreatitis.

A recent experience with seventy-seven patients admitted to Boston City Hospital for acute pancreatitis permitted us to identify thirteen patients (17 per cent) whom we diagnosed as having severe protracted acute pancreatitis. These alcoholic patients obviously had fulminant pancreatitis similar to that reported by others in two instances and pancreatic abscesses in two additional instances, but nine of the patients did not fulfill the criteria usually used by others as a basic for surgical intervention. Specific preoperative diagnosis was obtained in these patients by the aggressive use of endoscopic cannulation of the pancreatic ducts, which documented the presence of surgically correctable lesions. These patients had sustained significant malnutrition, which was corrected only by protracted therapy extending an average of two months and involving all modalities currently available for nutritional support of the severely ill patient. After proper preoperative identification of a specific lesion and correction of the malnutrition, the eleven patients without fulminant disease were operated on with no deaths or significant complication. Nine of the patients had elective procedures, which included six distal pancreatectomies and one total pancreatectomy. Thus, severe protracted acute pancreatitis can be identified, and once categrorized, it can have therapeutic implications.

Management of penetrating heart wounds.

The records of ninety-two patients treated between 1965 and 1976 at the Boston City Hospital for penetrating wounds of the heart were reviewed and the results were compared with a previous series of twenty-five patients admitted to the same institution between 1956 and 1964. The annual incidence rose from 2.8 cases during the first period to 8.0 during the more recent years. Gunshot wounds increased in frequency in the second period. The overall mortality was similar in the two series. However, there were more complex wounds and agonal patients subjected to immediate emergency room thoracotomy during the second phase of this experience. The salvage rate in the latter group of patients gradually improved and averaged 24% between 1965 and 1976. These data indicate that an aggressive approach, including the use of immediate thoracotomy, to the agonal patient with a heart wound will be rewarded with salvage of some patients.

Comparison of laparoscopic cholecystectomy with open cholecystectomy in a single center.

In this retrospective study, we compared the results of 1,283 open cholecystectomies (OCs) performed at our medical center during the pre-laparoscopic era with 1,107 laparoscopic cholecystectomies (LCs) performed from 1990 to 1992. There was no difference in the percentage of cases of acute and chronic cholecystitis in each time period (16.8% in each), nor were there differences in the patient characteristics for each group. The percentage of patients undergoing intraoperative cholangiography was similar for patients with chronic cholecystitis for each period, although the incidence of abnormal cholangiograms was lower in the laparoscopic era (5.8% versus 15.2%, p < 0.001). There was one bile duct injury in the OC group and three in the LC group (although one of these occurred after conversion ot an open procedure), but this difference was not statistically significant. However, there was a higher mortality rate in the patients with acute cholecystitis treated with OC (2.3% versus 0%, p = 0.03) and an increase in the overall complications in the patients with chronic cholecystitis in the OC group (7.5% versus 3.1%, p < 0.001) compared with the LC group. The increase in overall complications appeared to be primarily related to the increased rate of wound-related complications (3.6% versus 0%, p < 0.001) in the patients with chronic cholecystitis in the OC group. LC appears to be a safe procedure with a low incidence of complications including bile duct injury when performed by adequately trained surgeons.

Mesenteric ischemia.

Mesenteric ischemia secondary to vascular disease remains a significant problem in patients presenting with acute abdominal conditions, especially if they are elderly. Although rare, it is nevertheless an important and perhaps increasing cause of death or significant morbidity. Occasionally, it may be a mode of dying, but more often, it is the reason for death. Individual cases can manifest an almost overwhelming spectrum from chronic to acute, mild to catastrophic, arterial to venous, occlusive to hemodynamic, extensive to limited, or precisely diagnosed to accidentally found. Treatment principles are well defined, but continued refinement of supportive therapies of several types is occurring. In contrast, improved screening tests that can lead to early specific etiologic diagnosis remain at the experimental stage. Thus, good "clinical suspicion" is foremost and essential.

Obstruction of the large and small intestine.

This article provides an overview of mechanical small and large bowel obstruction with emphasis on newer diagnostic and therapeutic surgical techniques. Small and large intestinal pseudo-obstruction is discussed with reference to its diagnosis and appropriate treatment.

Unexpected findings in gastrointestinal tract surgery.

We discussed the proper management of patients with asymptomatic lesions incidentally found during laparotomy for other problems. For common or important lesions, information about the natural history, significance, treatment guidelines, and possible risks or complications related to operations on such incidentalomas were given. Thus, we discussed gallstones, masses of the upper and lower gastrointestinal tract, and masses in solid organs, such as liver, ovaries, and pancreas.