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Biomedical subjects

R A Prinz

Publications and source records attributed to R A Prinz.

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

Surgical approach to adrenal neoplasms: laparoscopic versus open adrenalectomy.

There are a number of different approaches available to surgically remove the adrenal gland. These can be broadly classified into two general categories, open and laparoscopic. There is no one best method for all patients. Surgeons, skilled in all aspects of adrenal surgery, should choose an approach for adrenalectomy based on patient and tumor related factors. Once advantages and disadvantages of a specific procedure, with these factors in mind, are weighed, the best approach for the individual patient should be chosen.

Adrenal Gland Neoplasms↗
PubMed1997

The effect of epidermal growth factor on the septic complications of acute pancreatitis.

Bacterial translocation (BT) from the gastrointestinal tract to mesenteric lymph nodes (MLN) and other extraintestinal organs is an important source of infection in acute pancreatitis (AP). Epidermal growth factor (EGF), a peptide hormone with trophic effects on gut mucosa, has decreased intestinal mucosal injury in septic rats and decreased burn-induced BT in mice. The purpose of this study is to examine whether EGF could affect BT in acute necrotizing pancreatitis. Forty-eight male Sprague-Dawley rats (250-350 g) were studied. AP was induced in Group I and Group II by pressure injection of 3% taurocholate and trypsin into the biliopancreatic duct (1 ml/kg of body weight). Group III and Group IV underwent laparotomy without induction of acute pancreatitis. Group I rats received human recombinant EGF (100 micrograms/kg, subcutaneously twice daily) and Group II rats received a similar volume of 0.1% bovine serum albumin as a placebo postoperatively. Group III and Group IV received EGF and placebo, respectively. At 48 hr postoperatively, blood was drawn for culture and amylase determinations. Jejunum and ileum were obtained to measure mucosal protein content, mucosal thickness, villus height, and crypt depth. Specimens from MLN, spleen, liver, pancreas, and cecum were harvested for pathology and culture of gram positive (G+), gram negative (G-), and anaerobic bacteria. Ileal mucosal protein levels were increased significantly in Group I (1.96 +/- 0.14 mg/cm) compared to Group II (0.95 +/- 0.15 mg/cm intestinal segment) (P < 0.01). Jejunal and ileal mucosal thickness, villus height, and crypt depth in Group I were significantly increased when compared to Group II (P < 0.05). All 12 rats in Group II had BT to MLN compared to 58% (7 of 12 rats) in Group I (P < 0.05). Thirty-three percent (4 of 12 rats) had BT to distant sites such as pancreas, spleen, liver, and/or blood in Group I vs 83% (10 of 12 rats) in Group II (P < 0.05). EGF treatment minimizes intestinal damage, decreases BT to MLN and bacterial spread to distant sites, and may be beneficial in preventing septic complications in AP.

Acute Disease↗
PubMed1997

User of fine-needle aspiration biopsy and frozen section in the management of the solitary thyroid nodule.

BACKGROUND: This study evaluates the indication for frozen section (FSx) in the management of the solitary thyroid nodule given the increasing use of fine-needle aspiration biopsy (FNAB). METHODS: The charts of 561 patients who underwent thyroidectomy for a solitary nodule were reviewed. Each patient underwent either FNAB, FSx, or both. Results were compared to the final diagnosis to evaluate their effectiveness in predicting malignancy. RESULTS: The sensitivity and specificity for FNAB alone (162 patients) were 86% and 91%, respectively, and for FSx (494 patients) 79% and 99%, respectively. The routine use of FSx with diagnostic FNABs did not improve the accuracy over either test alone. Sensitivity, specificity, and accuracy were essentially unchanged when the use of FSx was limited to just atypical FNAB but dropped significantly when FSx was not used. CONCLUSIONS: When results of FNAB and FSx are interpreted as benign or malignant, both are highly accurate predictors of malignancy. Routine use of FSx and FNAB does not improve the sensitivity or specificity in the detection of malignancy over that of either examination alone. FSx proved useful in determining the extent of operation only when results of the FNAB were atypical.

Biopsy, Needle↗
PubMed1997

Effectiveness of the thyroid scan in evaluation of the solitary thyroid nodule.

Solitary, palpable thyroid nodules are common, but only a small percentage are malignant. It is important to evaluate these nodules in a cost-efficient manner that avoids missing a cancer. Historically, radioisotope imaging has played a major role in the workup of thyroid nodules; however, with the advent of fine needle aspiration biopsy (FNAB), this role has become less clear. From 1974 to 1994, 770 patients with a solitary nodule underwent thyroidectomy. Preoperatively, 471 had thyroid scans, and 149 had FNAB. The incidence of carcinoma in nodules excised on the basis of thyroid scan was 23 per cent, whereas the incidence of carcinoma was 37 per cent when FNAB was used (P = 0.003). Fine needle aspiration was a significantly better predictor of malignancy than thyroid scan and resulted in a smaller proportion of excisions for benign nodules. Thyroid scan provided little additional information in those patients who underwent FNAB. Because thyroid scans add little in determining which nodules require surgical excision, they should no longer be a routine part of the evaluation of a solitary thyroid nodule.

Adolescent↗
PubMed1996

Adrenalectomy in the era of laparoscopy.

BACKGROUND: Recently laparoscopy has been described as an alternative approach for performing adrenalectomy. This study attempts to define the frequency and indications for the various approaches to adrenalectomy including laparoscopy. METHODS: From October 1992 to December 1995, 43 adrenal glands were excised from 40 patients, of whom 23 were women and 17 were men. Their ages ranged from 16 to 71 years. Nineteen operations were performed for pheochromocytoma, 10 for cortical adenoma (CAd), 6 for aldosteronoma, 4 for adrenocortical cancer (ACC), 1 for Cushing's disease (CD), and 1 for hemorrhagic cyst. Adrenalectomy was accomplished via a laparoscopic operation in 20 patients (8 CAds, 6 pheochromocytomas, 5 aldosteronomas, and 1 HC) and via an open operation in 19 patients (11 pheochromocytomas, 4 ACCs, 2 CAds, 1 CD, and 1 aldosteronoma). One patient with bilateral pheochromocytoma had an open and a laparoscopic adrenalectomy. RESULTS: Open operations included 15 transabdominal, 4 posterior, and 3 thoracoabdominal approaches for 22 glands. Laparoscopic operations included 17 transabdominal and 4 retroperitoneal approaches for 21 glands. Reasons for open operations included obesity (1), patient choice (2), failed laparoscopy (2), previous abdominal surgery (3), extraadrenal location (5); and gland size greater than 8 cm (9). Of these cases, the two patient choices, the two failed laparoscopies, and two of the three previous abdominal operations were appropriate for laparoscopy. Each of the posterior approaches could have been done laparoscopically. CONCLUSIONS: More than 60% of surgically treatable adrenal disease may be approached laparoscopically. Transabdominal, and on occasion, thoracoabdominal approaches are indicated for larger adrenal lesions. Surgeons operating on the adrenal gland should be familiar with each of these various approaches for adrenalectomy.

Adolescent↗
PubMed1996

Tumor angiogenesis in pheochromocytomas and paragangliomas.

BACKGROUND: Angiogenesis correlates with growth and likely metastases in several tumors. To determine whether it has a similar role in pheochromocytomas, immunohistochemical staining of factor VIII was done on the tumor tissue of 42 patients. METHODS: Formalin-fixed, paraffin-embedded tissue was obtained from 29 women and 13 men with 24 primary adrenal and 18 extraadrenal pheochromocytomas. Patients were divided into two groups. Group 1 included 32 patients with benign pheochromocytomas, and group 2 included 10 patients with malignant tumors evidenced by capsular or vascular invasion (six), liver metastases (three), or periaortic lymph node metastases (one). Blood vessels highlighted by factor VIII staining of endothelial cells with labeled streptavidin-biotin were counted under light microscopy. Mean vessel count within a 10 mm2 micrometer disk was calculated under x100, x200, and x400 magnification fields. RESULTS: There were no significant differences in patient age or clinical symptoms between the groups. The mean tumor size in group 2 of 8.8 +/- 5.3 cm was larger than the mean of 4.8 +/- 2.8 cm in group 1 (p < 0.005). The mean counts of vessels in the x100, x200, and x400 magnification fields were 102 +/- 48, 40 +/- 18, and 19 +/- 9 in group 1, and 203 +/- 77, 73 +/- 28, and 37 +/- 15 in group 2. The number of blood vessels in group 2 was significantly higher than in group 1 (p < 0.001) in each studied field. CONCLUSIONS: In this study the number of tumor blood vessels correlated with the invasive behavior of pheochromocytomas. Tumor angiogenesis may be useful in determining the likelihood of malignant behavior in pheochromocytomas.

Adolescent↗
PubMed1996

Effects of granulocyte colony-stimulating factor in severe pancreatitis.

BACKGROUND: The effect of granulocyte colony-stimulating factor (G-CSF) on the rate of secondary infections in acute pancreatitis was evaluated in a canine model. Infectious complications are the major determinant of morbidity and mortality in severe pancreatitis. Bacterial translocation has been shown to be a cause of these secondary infections. The relative immunosuppression found with pancreatitis may promote translocation and the spread of bacteria to the pancreas. METHODS: Thirty-four mongrel dogs were studied. Pancreatitis was induced in 18 dogs; 9 were treated with 100 micrograms G-CSF/day and 9 were given only saline solution. Laparotomy alone was done in 16 dogs of which one half were given 100 micrograms G-CSF/day and one half were given saline solution. Daily blood counts and cultures were obtained. All dogs were killed on day 7, and the mesenteric lymph nodes, pancreas, liver, spleen, and peritoneal fluid were cultured and studied histologically. RESULTS: G-CSF caused a significant and sustained increase in mature granulocytes in dogs given pancreatitis. No difference was found in the rate of translocation to mesenteric lymph nodes in dogs given G-CSF (n = 4) versus dogs given saline solution (n = 6). However, a significant decrease occurred in the spread of bacteria to distant sites in dogs given G-CSF (1 versus 15, p < 0.05). CONCLUSIONS: Although G-CSF does not decrease the rate of translocation, it does decrease the rate of distant infection in severe acute pancreatitis.

Acute Disease↗
PubMed1995

A comparison of laparoscopic and open adrenalectomies.

OBJECTIVE: To compare the relative merits of conventional transabdominal and posterior methods with a laparoscopic approach for adrenalectomy. DESIGN: A retrospective cohort study of consecutive series of patients having unilateral adrenalectomy for lesions less than 10 cm in diameter. SETTING: University hospital. PATIENTS: Ten patients who underwent laparoscopic adrenalectomy: 11, transabdominal adrenalectomy; and 13, posterior adrenalectomy. MAIN OUTCOME MEASURES: Operative time, estimated blood loss, length of hospital stay, and postoperative parenteral analgesic need. RESULTS: There was no significant difference in the operative time for laparoscopic and anterior adrenalectomy (mean +/- SD, 212 +/- 77 minutes vs 174 +/- 41 minutes), but the time for posterior adrenalectomy was significantly shorter (139 +/- 36 minutes) (P < .01). The mean (+/- SD) hospital stay after laparoscopic removal (2.1 +/- 0.9 days) was significantly shorter than the stay after anterior (6.4 +/- 1.5 days) and posterior (5.5 +/- 2.9 days) adrenalectomy. The postoperative need for parenteral pain medication as measured by the number of doses and the total milligrams of meperidine hydrochloride administered was significantly less with laparoscopic adrenalectomy compared with either open procedure (P < .0001). CONCLUSIONS: Laparoscopic adrenalectomy may take longer to perform than conventional open approaches but it has clear-cut advantages in shortening postoperative hospital stay and lessening postoperative analgesic requirements. It may be the preferred method for most patients requiring adrenalectomy.

Adrenalectomy↗
PubMed1995

Utilization of fine-needle aspiration biopsy in the diagnosis of metastatic tumors to the pancreas.

There is relatively little information concerning the use of fine-needle aspiration biopsy (FNAB) to diagnose a mass in the pancreas that is secondary to metastatic tumor. This study reviews the incidence and types of neoplasms which metastasize to the pancreas and assesses the contribution FNAB can make in their diagnosis. Of 117 radiologically guided FNABs of the pancreas, 11% (n = 13) showed metastatic malignancy. Nine patients had a previous history of malignancy while four patients presented with a pancreatic mass and were subsequently found to have wide-spread malignant disease. The majority of metastatic lesions were epithelial (77%, n = 10). Patient outcomes were generally poor (mean survival 2.8 mo). Metastases to the pancreas occur from a variety of primary sites and should be considered in patients with a pancreatic mass and a history of prior malignancy. FNAB is useful in diagnosing these metastases and this is clinically important because of their poor prognosis.

Adult↗
PubMed1995

Selection of patients with adrenal incidentalomas for operation.

An adrenal mass may be discovered incidentally in as many as 2% of patients having an abdominal CT scan. The clinical dilemma is to identify the rare functioning or malignant adrenal tumor, which warrants resection, while avoiding unnecessary testing and surgery in the majority of patients whose adrenal lesions are nonfunctioning and benign. A thorough history and physical examination and judicious use of screening laboratory tests are important in determining the likelihood of a clinically significant adrenal mass. There is little debate that functional or large (< 6 cm) adrenal masses should be excised; adrenalectomy for adrenal masses 3 to 6 cm in patients younger than 50 years of age and for those masses with ominous CT characteristics also is advised. Observation with serial CT scans and screening studies are recommended for patients 50 years of age or older whose adrenal masses are between 3 to 6 cm and for all patients with hormonally inactive masses that are smaller than 3 cm.

Adrenal Gland Diseases↗
PubMed1995

Neck radionuclide scanning: a pitfall in parathyroid localization.

UNLABELLED: Radionuclide parathyroid scans are widely used to localize abnormal parathyroid glands. They are especially valuable for identifying ectopic glands, including those in the mediastinum. Two patients with hyperparathyroidism who had mediastinal glands that were not identified because only the neck was scanned prompted our review of the technique of parathyroid scanning at hospitals in our region and of the frequency of mediastinal parathyroid glands identified by scanning at our own institution. The nuclear medicine departments at 72 area hospitals were surveyed. Parathyroid scans were performed at 51 of these hospitals but only 13 (25%) routinely scanned the mediastinum and chest. At our institution 480 parathyroid scans were performed during a 9-year period. Twenty-six mediastinal parathyroid glands were identified by routine scanning of both the neck and mediastinum. Most of these glands could be removed through a cervical incision. However, four required formal thoracotomy and two thoracoscopy. CONCLUSIONS: A radionuclide parathyroid scan limited to the neck is an incomplete study. Scans that do not include the thorax will miss mediastinal glands that occurred in 5 per cent of the patients in our series. Despite this, radionuclide parathyroid scanning was limited to the neck in 75 per cent of surveyed hospitals. This practice increases the chance for failed surgical exploration and increases potential patient morbidity.

Adenoma↗
PubMed1995

Prospective evaluation of the safety and efficacy of laparoscopic jejunostomy.

We prospectively assessed the safety and efficacy of laparoscopic jejunostomy done by 11 surgeons in 8 medical centers using the T-fastener technique. In all, 23 men and 13 women aged 19 to 84 (mean, 59) years required enteral feeding, but could not undergo gastrostomy and had no contraindication to laparoscopy. Of these patients, 12 had head and neck cancer and 11 had neurologic swallowing dysfunction. The procedure took 25 to 180 minutes (mean, 75). Three (8%) early cases were converted to open jejunostomy because of accidental enterotomies caused by inappropriate techniques that were avoided in later cases. Minor technical problems, such as passing a needle through the back wall of the jejunum, occurred in 7 patients, but they were easily corrected and produced no complications. Feedings were routinely begun within 24 hours of the surgical procedure. All jejunostomy catheters functioned well. This is a safe and effective technique when done by experienced laparoscopic surgeons, and serious complications are rare.

Adult↗
PubMed1995

Simultaneous fine-needle aspiration and core-needle biopsy of thyroid nodules.

To evaluate the efficacy of simultaneous fine-needle aspiration (FNA) and core-needle (CN) biopsies of thyroid nodules, the clinical course and operative findings in 100 patients having both tests were reviewed. Each patient had a diagnosis made with this approach. Both specimens were adequate for diagnosis in 95 patients. In the remaining 5 patients, a diagnosis was provided by FNA in four and CN biopsy in one. FNA and CN biopsies gave the same diagnosis of either a benign nodule in 53 patients or neoplasia in 30 patients. When both FNA and CN biopsies showed a benign nodule, a nonoperative approach was taken in 43 of the 53 patients. Forty-two patients were operated on either because of biopsy findings (32) or clinical indications (10). The surgical specimens were used to determine the false positive and false negative rates, the sensitivity, specificity, and accuracy for the diagnosis of neoplasia. The false (+) and false (-) rates in diagnosing neoplasia were 33 per cent and 7 per cent for FNA, 20 per cent and 4 per cent for CN biopsy, and 20 per cent and 0 per cent for both. The sensitivity, specificity, and accuracy for FNA were 93 per cent, 67 per cent, and 83 per cent, for CN biopsy 96 per cent, 80 per cent, and 90 per cent, and 100 per cent, 80 per cent, and 93 per cent for both FNA and CN. All neoplasms were detected, and no thyroid carcinomas were missed by this combination. There was only one complication: bleeding after a CN biopsy. Combined FNA and CN biopsies allow most patients with thyroid nodules to avoid an unnecessary operation and accurately diagnose those with thyroid carcinoma. These two procedures are safe and complementary.

Adenocarcinoma, Follicular↗
PubMed1994

Pancreatic pseudocyst resolution after parathyroidectomy for hyperparathyroidism.

Hyperparathyroidism is a rare cause of pancreatic inflammatory disease. Appropriate treatment of coexistent hyperparathyroidism and pancreatitis, especially when complicated by pseudocyst formation, is unsettled. We describe two patients with primary hyperparathyroidism who developed pancreatitis associated with multiple pseudocysts. The largest cyst in each patient was 9 and 5 cm, respectively. After correction of hyperparathyroidism and normalization of serum calcium levels by removal of a parathyroid adenoma, the pseudocysts resolved in both patients, as documented with computed tomography. We conclude that uncomplicated pancreatic pseudocysts in patients with primary hyperparathyroidism can be treated expectantly. Surgical correction of hyperparathyroidism and normalization of serum calcium levels should precede pancreatic intervention when possible, since pseudocyst resolution is likely and the risks of postoperative hypercalcemia are avoided.

Acute Disease↗