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Biomedical subjects

A G Patel

Publications and source records attributed to A G Patel.

At least 37 records · Page 2Linked to original sources
PubMed1998

Superselective microcoil embolization: treatment of choice in high-risk patients with extrahepatic pseudoaneurysms of the hepatic arteries.

BACKGROUND: Only a few isolated case reports of extrahepatic pseudoaneurysms of the hepatic arteries have been published. We present the first documented series of patients with extrahepatic pseudoaneurysms treated at a single institution, and discuss the etiology and management of this condition. STUDY DESIGN: A retrospective review of all cases of extrahepatic pseudoaneurysms of the hepatic arteries between 1989 and 1997. RESULTS: A total of seven patients with extrahepatic pseudoaneurysms of the hepatic arteries all had upper abdominal pain; five patients were also in shock secondary to a gastrointestinal bleeding from ruptured pseudoaneurysms. The most common factor of the pseudoaneurysms was previous pancreatobiliary surgery in five patients with blunt truncal trauma and chronic pancreatitis in the remaining two patients. Initial endoscopy and ultrasonography were unrevealing, whereas dynamic computed tomography (CT) scan and angiography were diagnostic. The median size of the pseudoaneurysms was 3.6 cm (range 2.1-5.7). Treatment consisted of superselective transcatheter microcoil embolization in five hemodynamically unstable patients and surgical resection of the pseudoaneurysms with vascular reconstruction in the two stable patients. Mortality and morbidity were 0% and 43%, respectively. In a median followup of 35 months (range 2-96), no recurrence of pseudoaneurysm has been found. CONCLUSIONS: A high index of suspicion combined with appropriate diagnostic modalities are required for the diagnosis of extrahepatic pseudoaneurysms. In high-risk patients, superselective transcatheter microcoil embolization should be considered the treatment of choice.

Aneurysm, False↗
PubMed1998

Ethanol-mediated neutrophil extravasation in feline pancreas.

Ethanol is a common cause of both acute and chronic pancreatitis. Studies in other organs suggest that polymorphonuclear neutrophils activated by ethanol may cause tissue injury in a variety of conditions. The aim of this study was to investigate the effects of ethanol on neutrophil extravasation in the feline pancreas. Pancreata were isolated and perfused at different flow rates with varying concentrations of ethanol in either a physiological or neutrophil depleted perfusate. Neutrophil extravasation was assessed by measuring pancreatic tissue myeloperoxidase (MPO) activity. Ethanol at 2.5% (54.25 mmol/liter) was the lowest concentration that still caused significant neutrophil extravasation (3.1+/-0.8 vs 1.9+/-0.2 units, P<0.05) and was accompanied by an increase in vascular resistance of 15%. Reduction of pancreatic perfusion by 15% did not significantly increase neutrophil extravasation. (1.1+/-0.3 vs 1.6+/-0.2 units, NS) Perfusion of the pancreas with neutrophil-depleted blood containing either ethanol or saline, followed by perfusion with an ethanol-free perfusate, showed an increase in neutrophil extravasation in the ethanol group compared to the control group (3.2+/-0.9 vs 1.9+/-0.2 units, P<0.05). In conclusion, ethanol causes neutrophil extravasation in the feline pancreas independent of blood flow changes and occurs despite the absence of direct neutrophil exposure to ethanol.

Animals↗
PubMed1998

Missed diaphragmatic injuries and their long-term sequelae.

BACKGROUND: Blunt or penetrating truncal traumas can result in diaphragmatic rupture or injury. Because diaphragmatic defects are difficult to diagnose, those that are missed may present with latent symptoms of obstruction of herniated viscera. METHODS: A chart review of all patients admitted with late presentations of posttraumatic diaphragmatic hernias from 1980 to 1996 was undertaken. RESULTS: Ten patients with posttraumatic diaphragmatic hernias were treated in this specified period. There were six males and four females with a mean age of 65 years. Eight patients sustained blunt truncal traumas and two patients sustained penetrating truncal traumas. The hernias occurred in two patients on the right and in eight patients on the left side and contained the liver (n = 2), bowel (n = 10), stomach (n = 4), omentum (n = 5), or spleen (n = 1). The time until the hernias became clinically symptomatic ranged from 20 days to 28 years. In all but one patient, either routine chest roentgenograms or upper gastrointestinal contrast studies were diagnostic. All 10 patients underwent laparotomy (n = 9) or thoracotomy (n = 2) with direct repair of the diaphragmatic defect. One patient died 3 days after the operation, representing a mortality of 10%; the morbidity was 30%. CONCLUSION: Initial recognition and treatment of diaphragmatic rupture or injury is important in avoiding long-term sequelae.

Adult↗
PubMed1998

Stenting does not decompress the pancreatic duct as effectively as surgery in experimental chronic pancreatitis.

BACKGROUND: In humans with chronic pancreatitis (CP), pancreatic interstitial pressure (IP) is elevated and pancreatic blood flow (PBF) is reduced. The efficacy of surgical decompression (SD) of the pancreatic duct (ie, pancreaticojejunostomy) is believed to be due to its ability to decrease IP and pancreatic vascular resistance (Rp), which increases PBF. Pancreatic duct stenting (STE) also probably reduces IP and Rp, which may explain its efficacy. The purpose of this study was to compare the efficacy of SD with STE. METHODS: CP in cats was created by narrowing the main pancreatic duct. Six weeks later, CP and normal pancreata were isolated and perfused ex vivo under basal conditions and after secretin stimulation. In normal and CP glands, IP and perfusion pressure were measured and Rp (U) was calculated. In two additional groups, the pancreatic duct was decompressed, either by stenting or by complete transection of the duct with a longitudinal capsulotomy. RESULTS: In CP glands, IP and Rp were increased and secretory output was markedly reduced compared with the normal (0.65 +/- 0.30 mm Hg and 0.46 +/- 0.04 U vs 3.90 +/- 0.80 mm Hg and 1.68 +/- 0.05 U; P < .05). Secretin administration (2 units) increased IP and Rp in CP glands (6.60 +/- 1.10 mm Hg and 2.87 +/- 0.07 U; P < .05), but these values did not chang in normal glands (0.81 +/- 0.20 and 0.53 +/- 0.03 U; NS). STE and SD decreased IP and Rp in CP glands (2.20 +/- 0.20 to 1.0 +/- 0.40 mm Hg and 1.20 +/- 0.015 to 0.90 +/- 0.01 U, respectively; P < .05). Both methods prevented an increase of IP and Rp after secretin administration. IP and Rp decreased to a greater degree following SD, compared with STE (P < .05). CONCLUSIONS: Both STE and SD decreased IP and Rp in this experimental model of CP. However, SD was significantly more effective than STE.

Animals↗
PubMed1998

Port site metastases following laparoscopic cholecystectomy for unsuspected carcinoma of the gallbladder.

Laparoscopic cholecystectomy is considered as the new gold standard operation for removal of the gallbladder, and has several advantages over the traditional open cholecystectomy. However, in the last few years there is an increasing number of case reports of port site metastases following laparoscopic cholecystectomy for unsuspected carcinoma of the gallbladder. Two case reports of trocar site metastases are presented, and they further highlight the concern of the role of minimal invasive surgery in the presence of unsuspected carcinoma of the gallbladder. In this review we speculate on the mechanisms which may be responsible for metastatic deposits during laparoscopic cholecystectomy and suggest certain recommendations.

Abdominal Muscles↗
PubMed1997

Effect of ethanol on pancreatic interstitial pH and blood flow in cats with chronic pancreatitis.

OBJECTIVE: The objective of this study was to investigate the effects of ethanol on pancreatic blood flow and interstitial pH in chronic pancreatitis. BACKGROUND: Ethanol is known to contribute to the development of both acute and chronic pancreatitis. However, it is unclear how ethanol precipitates episodes of acute pancreatic inflammation in the setting of chronic pancreatitis. In a model of chronic pancreatitis in cats, it is known that pancreatic blood flow is abnormally low and decreases further after ethanol ingestion. Because it is possible that this reduction in blood flow might be damaging to the pancreas, we investigated the effects of ethanol on pancreatic interstitial pH, an index of pancreatic ischemia. METHODS: In normal cats and cats with obstructive chronic pancreatitis, pancreatic blood flow and interstitial pH were measured using the hydrogen gas clearance technique and pH microelectrode, respectively. RESULTS: In normal cats, intragastric, but not intravenous, ethanol reduced both pancreatic blood flow by 62% (p < 0.05) and interstitial pH (7.38 +/- 0.03 to 7.20 +/- 0.03, p < 0.05). In cats with chronic pancreatitis in which basal pancreatic blood flow was already only 60% of normal flow, both intragastric and intravenous ethanol decreased both pancreatic blood flow (intragastric, 40% decrease, p < 0.05; intravenous, 34% decrease, p < 0.05) and interstitial pH (intragastric, 7.24 +/- 0.04 to 7.08 +/- 0.04, p < 0.05; intravenous 7.20 +/- 0.08 to 7.07 +/- 0.07, p < 0.05). CONCLUSIONS: This profound decrease in pH, lasting up to 2 hours after ethanol exposure in the chronic pancreatitis animals, suggests the possibility of ischemic cellular damage to the pancreas. These findings may explain the pathogenesis of bouts of acute pancreatic inflammation after ethanol ingestion in the setting of chronic disease.

Animals↗
PubMed1997

Gout: rare cause of hallucal sesamoid pain: a case report.

Tophaceous gout is commonly encountered and is amenable to effective medical management. A rare case of tophaceous gout in a tripartite medial sesamoid bone of the great toe is presented. Clinical presentation, differential diagnosis, and treatment of hallucal sesamoid pain are discussed.

Acute Disease↗
PubMed1996

Post-traumatic osteolysis of the distal clavicle.

We report a case of post-traumatic osteolysis of the distal clavicle of a 25-year-old man. The diagnosis was missed for several months, and the patient continued to have pain in his right shoulder. The pain continued in spite of intensive physiotherapy. When he was seen for the first time in our clinic 6 months after the accident, the radiographs showed an osteolysis of the distal clavicle.

Acromioclavicular Joint↗
PubMed1996

Palliation for pancreatic cancer. Feasibility of laparoscopic cholecystojejunostomy and gastrojejunostomy in a porcine model.

BACKGROUND: Although laparoscopy reveals undetected metastases in many patients with pancreatic cancer, most surgeons have chosen to proceed directly with laparotomy in an attempt at resection or for palliation of biliary and gastric outlet obstruction. In an effort to overcome this limitation, this study attempted to determine the feasibility of laparoscopic cholecystojejunostomy and gastrojejunostomy. METHODS: Under general anesthesia, seven pigs underwent laparoscopic cholecystojejunostomy and gastrojejunostomy using either a hand-sutured or the stapled/sutured technique. RESULTS: Mean operating time was less with the stapled/sutured vs hand-sutured technique (150 +/- 21 vs 230 +/- 13 min, P < 0.05). All animals recovered completely and there was no change in their weight or liver function tests as a result of the procedure. At sacrifice, all anastomoses were patent, although some were significantly narrowed in these unobstructed animals. CONCLUSIONS: These results suggest that simultaneous laparoscopic palliation of biliary and gastric outlet obstruction is feasible. We believe these results warrant further study in the clinical setting.

Anastomosis, Surgical↗
PubMed1996

Recovery from depressive illness does fit an exponential model.

A very large number of therapeutic trials of antidepressant drugs have been reported in the scientific literature. Until now, the comparison of one drug with another, or with placebo, has been performed typically by comparing the scores on depression rating scales of the two groups of patients at fixed points of time after the beginning of therapy. It was postulated in 1989 that the curves of the recovery scores followed an exponential curve of the formula y = ae-bx + c. This hypothesis was tested in a double-blind controlled trial of the antidepressant minaprine, with the use of the scores on the Hamilton Rating Scale for Depression (HAM-D). We found that the correlation coefficient, Pearson's r, between the log of the HAM-D value and the week number of the study was -0.99. This gives a coefficient of determination of 0.98, which makes it clear that the model adequately fits the data. We conclude that the use of the formula gives a method of testing the statistical significance of the difference between treatments as a valuable alternative to traditional tests. We believe that this would give a much more sensitive discrimination between treatments because all of the data points are used to calculate a single parameter--the slope of the curve.

Antidepressive Agents↗
PubMed1995

Pylorus-preserving Whipple resection for pancreatic cancer. Is it any better?

OBJECTIVE: To compare the short- and long-term morbidity and mortality rates of the standard Whipple pancreatoduodenectomy (SW) and its pylorus-preserving modification (PPW) in patients with malignant periampullary disease. DESIGN: Retrospective medical record review and quality of life assessment by telephone interview. SETTING: University medical center. STUDY PARTICIPANTS: Sixty-seven patients who underwent pancreatoduodenectomy (52 SW and 15 PPW) from June 1988 to January 1994. INTERVENTION: The SW and PPW. MAIN OUTCOME MEASURES: Operative features and short- and long-term complications were analyzed with respect to the type and stage of cancer and the kind of pancreatic resection. Mean follow-up was 32 months (range, 1 to 5 years). RESULTS: The operative mortality rate for all patients who had a pancreatic resection was 1.5%. The diagnoses in the PPW vs SW groups were pancreatic cancer (four vs 27 patients), ampullary cancer (six vs seven patients), duodenal cancer (zero vs six patients), and bile duct cancer (five vs one patient). Operative mortality rates (0% vs 1.55%) and operative times (2 minutes longer for SW) were similar. Delayed gastric emptying (61% vs 41%) was more common in the PPW group, resulting in a longer hospitalization (24 vs 18 days) and a greater cost in the PPW group (P = .04). In the PPW group, a mean of five lymph nodes was removed compared with 10 in the SW group (P = .04). CONCLUSIONS: The data provided no evidence of any advantage for the PPW in patients with malignant periampullary tumors. We continue to advocate the SW for pancreatic cancer.

Adult↗
PubMed1995

Role of nitric oxide in the relationship of pancreatic blood flow and exocrine secretion in cats.

BACKGROUND/AIMS: Recent studies have suggested that, in the gastrointestinal tract, nitric oxide is an important mediator of alterations in blood flow and, in some organs, a second messenger involved in secretion. This study examined the role of NO in changes in pancreatic blood flow associated with basal and stimulated pancreatic exocrine secretion. METHODS: In anesthetized cats, we determined the effects of the NO synthase inhibitor NG-monomethyl-L-arginine (10 mg/kg) and the NO donor sodium nitroprusside (10 micrograms.kg-1.min-1) on pancreatic secretion and blood flow (hydrogen gas clearance). RESULTS: NG-monomethyl-L-arginine had no effect on the increase in blood flow associated with secretin stimulation (271 +/- 52 vs. 290 +/- 50 mL.min-1.100 g-1) but reduced that associated with cholecystokinin stimulation (189 +/- 17 vs. 53 +/- 15 mL.min-1.100 g-1; P < 0.001). In contrast, NG-monomethyl-L-arginine significantly reduced both secretin- and cholecystokinin-stimulated secretion. Sodium nitroprusside had no effect on basal blood flow but significantly increased secretion. CONCLUSIONS: NO has a selective role in mediating changes in pancreatic perfusion and secretion. It seems to be important in stimulus-secretion coupling with both secretin and cholecystokinin but is only responsible for the accompanying increase in pancreatic blood flow with cholecystokinin.

Amino Acid Oxidoreductases↗
PubMed1995

Pancreatic interstitial pH in human and feline chronic pancreatitis.

BACKGROUND & AIMS: Advanced chronic pancreatitis is associated with a reduction in pancreatic blood flow. To determine the physiological significance of this decrease, pancreatic interstitial pH was measured in a model of obstructive chronic pancreatitis in cats and in patients with chronic pancreatitis. METHODS: In cats, pancreatic interstitial pH and blood flow were measured serially under basal conditions and after secretory stimulation as chronic pancreatitis evolved. Basal pancreatic interstitial pH was also measured in patients undergoing an operation for chronic pancreatitis or periampullary cancer (controls). RESULTS: In normal cats, pancreatic interstitial pH was 7.41 +/- 0.01 and blood flow was 124 mL.min-1.(100 g pancreas-1). With the evolution of chronic pancreatitis, interstitial pH and blood flow progressively decreased to 7.21 +/- 0.04 (P < 0.007) and 75 +/- 11 (P < 0.007), respectively. From 1 to 2 weeks, secretory stimulation reduced pancreatic interstitial pH and blood flow further, but as secretory function was lost, this effect disappeared. In patients with chronic pancreatitis, the interstitial pH was lower (7.02 +/- 0.06) than in controls (7.25 +/- 0.04; P < 0.05). CONCLUSIONS: These observations are consistent with the hypothesis that, in chronic pancreatitis, acidic metabolites associated with pancreatic secretion accumulate within the pancreas, probably because of impaired blood flow.

Adult↗