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P P Schachter

Publications and source records attributed to P P Schachter.

8 recordsLinked to original sources
PubMed2000

The impact of laparoscopy and laparoscopic ultrasonography on the management of pancreatic cancer.

HYPOTHESIS: Laparoscopy and laparoscopic ultrasonographic (LAPUS) examinations combined with a biopsy of the pancreatic lesion contribute significantly in the determination of resectability of pancreatic cancer. DESIGN: A prospective evaluation of the impact of laparoscopy and LAPUS on surgical decision making in patients with pancreatic cancer. SETTING: A general community hospital; the department of surgery serves as referral for pancreatic surgery. PATIENTS: During a 36-month period, 94 patients with pancreatic lesions were prospectively examined. Twenty-seven patients were found to have advanced disease. The remaining 67 patients were examined by laparoscopy and LAPUS to determine the resectability of the pancreatic tumor. RESULTS: Laparoscopy and LAPUS contributed new, additional data in 40 patients (60%). Advanced disease was found in 30 patients, precluding curative resection. The study indicated potentially resectable tumors in 37 patients (55%), including 3 defined by conventional imaging studies as probably unresectable, and these patients were operated on with the intention of curative resection. Thirty-three patients underwent resection, and 4 (6%) were found to have nonresectable disease and form the false-positive group of the study. A summary of the results shows that the study resulted in a change of the decision regarding surgical intervention in 24 patients (36%) and avoided unnecessary laparotomies in 21 (31%). The study had a sensitivity of 100%, a specificity of 88%, and a false-positive rate of 6%. The positive predictive value of the study is 89%, and the negative predictive value is 100%. CONCLUSIONS: Although rather invasive procedures that require general anesthesia and hospitalization, laparoscopy and LAPUS significantly contribute to the staging of patients with potentially resectable pancreatic cancer, avoiding unnecessary explorative laparotomies. These procedures should be performed in all patients with potentially resectable pancreatic cancer before explorative laparotomy.

Female↗
PubMed2000

The impact of laparoscopy and laparoscopic ultrasound on the management of pancreatic cystic lesions.

HYPOTHESIS: Laparoscopic ultrasound examination combined with biopsy of the cystic wall and aspiration of cystic fluid improves differential diagnosis of pancreatic cystic lesions contributing to surgical decision making. STUDY DESIGN: A prospective evaluation of the impact of laparoscopic ultrasound on surgical decision making in patients with pancreatic cysts. SETTING: A general community hospital; the department of surgery serves as referral for pancreatic surgery. PATIENTS: During a 36-month period, 15 patients with pancreatic cystic lesions were prospectively evaluated by laparoscopy and laparoscopic ultrasound with ultrasound-guided biopsy of the cystic wall and aspiration of cystic fluid for cytologic study, viscosity, and determination of levels of amylase and tumor markers (carcinoembryonic antigen, cancer antigen 19.9). RESULTS: Laparoscopic ultrasound contributed new, additional data in 8 patients (53%) when compared with compiled imaging data obtained by conventional ultrasound, computed tomography, magnetic resonance imaging, and endoscopic ultrasound. A solid cystic component was detected in 6 patients and additional small (<1 cm) cysts in 3 patients. Amylase and tumor marker levels, biopsy of the cystic wall, and cytologic examination had significant impact on surgical decision making in 6 patients. Nine patients underwent resection of the cystic lesion. Three patients diagnosed as having benign cysts had laparoscopy with laparoscopic ultrasound only. Three patients with suspicious lesions refused surgery. Laparoscopic ultrasound predicted correctly the nature of the cyst in 7 of 9 surgically treated patients (sensitivity, 78%). Two patients with serous cystadenoma had high levels of tumor markers (false-positive). CONCLUSION: Although a rather invasive procedure that requires general anesthesia and hospitalization, laparoscopy with laparoscopic ultrasonography was found to significantly contribute to the differential diagnosis of pancreatic cystic lesions.

Adult↗
PubMed1995

Correct preoperative localization: does it permit a change in operative strategy for primary hyperparathyroidism?

BACKGROUND: A meticulous bilateral neck exploration by an experienced endocrine surgeon offers a high cure rate with low morbidity for patients with primary hyperparathyroidism. The advent of localizing studies raises the possibility of unilateral neck exploration. The cost-effectiveness of preoperative localizing studies and unilateral neck exploration in primary hyperparathyroidism are controversial issues. This study was designed to determine the risks of missing a contralateral pathologic parathyroid gland in patients with preoperative localization that was confirmed at neck exploration. METHODS: Preoperative studies (ultrasonography, nuclear radioactive imaging scan, or both) were performed in 79 patients with primary hyperparathyroidism. In 58 patients a definite localization of an enlarged parathyroid gland was confirmed at operation. All patients underwent a meticulous bilateral neck exploration. RESULTS: Unilateral neck exploration was feasible only in 73.4% of the patients, according to our localizing modalities, and an additional enlarged parathyroid gland on the contralateral side, not detected before operation, was revealed in five patients (8.6%). False-positive rates were 1.7% for ultrasonography and 13% for scan. CONCLUSIONS: These results indicate an unacceptably high surgical failure rate for unilateral neck exploration guided by preoperative localizing studies compared with a bilateral neck exploration by an experienced endocrine surgeon, questioning the cost-effectiveness of preoperative localizing studies.

Adenoma↗
PubMed1994

Total proctocolectomy, pancreaticoduodenectomy and total gastrectomy for multiple carcinomas in a patient with familial adenomatous polyposis.

A unique case of familial adenomatous polyposis presenting with simultaneous adenocarcinoma of the periampullary region, gallbladder and several gastric lesions, 10 years after a total proctocolectomy, is reported. Multiple gastrointestinal carcinomas associated with familial polyposis have been reported sporadically. However, this is the only known patient who successfully underwent a pancreaticoduodenectomy (Whipple procedure) and a total gastrectomy in addition to a previous total proctocolectomy.

Adenocarcinoma↗
PubMed1992

Non-autonomy of parathyroid hormone secretion in acute primary hyperparathyroidism.

A patient with acute primary hyperparathyroidism treated with mithramycin preoperatively, underwent neck exploration and two enlarged parathyroid glands were excised: one huge adenoma (6g) and another smaller gland. Mithramycin was administered preoperatively to lower life-threatening hypercalcaemia, and parathyroid slices from the huge adenoma removed at surgery were submitted in vitro to various calcium concentrations in the media to determine the influence of calcium on parathyroid adenoma secretory pattern in acute primary hyperparathyroidism. Mithramycin induced a significant decline in calcium levels and significant elevations of calciotrophic hormones (intact PTH, mid-region specific PTH, calcitonin and calcitriol). Significant suppression in PTH output in vitro was achieved by increasing calcium levels in the media. These results exclude autonomous PTH secretion (non-calcium dependent) as a possible aetiology of acute primary hyperparathyroidism. We suggest that a sudden increase in the set-point of the diseased parathyroid cells in the presence of a huge cell mass accounts, in large part, for both the marked hypercalcaemia and elevated PTH levels in this patient.

Acute Disease↗
PubMed1991

Parathyroid hormone secretion and target organ response in experimental acute pancreatitis.

To determine changes in parathyroid hormone secretion and target organ response caused by acute pancreatitis before the development of systemic toxic conditions, experimental acute pancreatitis was induced in rats with a choline-deficient, ethionine-supplemented diet. After 7 days, the rats were weighed and bled, and one kidney was assayed for 25-hydroxyvitamin D1 hydroxylase activity. Several manifestations of pancreatitis were observed in rats given the diet: weight loss (from 29.6 to 26.3 g vs that for control rats, from 29 to 52.8 g) and lower dietary intake (15.5 vs 47 g per rat per 7 days). Serum amylase levels fell from 1794 to 350 U/L in rats given the choline-deficient, ethionine-supplemented diet compared with levels of 1800 to 2100 U/L in control rats. The pancreases of rats given the choline-deficient, ethionine-supplemented diet showed degeneration, necrosis, and hemorrhaging. Serum levels of calcium, phosphorus, chloride, and parathyroid hormone did not change significantly throughout the experiment. Renal 25-hydroxyvitamin D1 hydroxylase activity was higher than in control rats (8.9 +/- 0.8 vs 7.6 +/- 0.6 fmol/mg of kidney per minute). Acute pancreatitis in this experimental animal model does not alter serum levels of calcium and parathyroid hormone or reduce target organ responsiveness to the hormone.

25-Hydroxyvitamin D3 1-alpha-Hydroxylase↗
PubMed1991

The role of circulating N-terminal parathyroid hormone fragments in the early postparathyroid adenomectomy period.

Calcium metabolism and hormonal control after parathyroid adenomectomy are poorly understood. During the first postoperative hours, biologically active intact parathyroid hormone (PTH) (hPTH 1-84) levels are subnormal and, in spite of down-regulation of PTH peripheral receptors (caused by hypercalcemia before surgery), total and ionized calcium concentrations are maintained in the normal range. Serum samples from 20 patients with primary hyperparathyroidism were collected in the immediate preoperative period and 4 and 48 hours after excision of one parathyroid adenoma. Total and ionized calcium, intact (iPTH), midregion (mrPTH) specific PTH (hPTH 53-68), and N-terminal PTH (N-PTH) serum concentrations were determined. Levels of N-PTH were obtained with a radioimmunoassay by a modified reverse immunoextraction procedure that measures N-PTH fragments after exclusion of the interfering iPTH. No significant correlation was found between ionized and total calcium, mrPTH, and iPTH. However, total and ionized calcium levels correlated well with N-PTH (r = 0.9999, p = 0.0054, and r = 0.9993, and p = 0.0226, respectively). The data suggest that the relatively moderate decrease in calcium levels, in spite of marked decrease in circulating iPTH during the first postoperative hours, may be attributable to the minimal decrease of the bioactive N-PTH epitope concentrations. We would hypothesize that hPTH (1-34) fragments may play a significant role in regulating serum calcium levels in the early postoperative period.

Adenoma↗