PubMed Health⌕ Search

Biomedical subjects

B M Jaffe

Publications and source records attributed to B M Jaffe.

At least 37 records · Page 2Linked to original sources
PubMed1993

Parathyroid localization prior to primary exploration.

The success of parathyroid surgery is based on accurate localization of normal and abnormal parathyroid glands, knowledge of the pathologic conditions, and meticulous dissection during removal of the abnormal glands. Although parathyroid localization is essential in cases requiring re-exploration, there is considerable controversy regarding the indications for localization studies prior to primary exploration, since the success rate for surgery exceeds 90% to 95%. However, in specific circumstances, including diagnostic problems, technical considerations, and high-risk patient factors, preoperative parathyroid localization assists the operating surgeon even during the primary cervical exploration. The purpose of this paper is to define these specific circumstances and discuss the appropriate studies.

Adolescent↗
PubMed1992

Evaluation of a rat model for the study of local regulation of intestinal blood flow: ex vivo asanguineous perfusion of the ileal vascular bed.

A new model of ex vivo vascularly perfused, isolated rat ileum was developed and evaluated. Segments of distal ileum (approximately 5 cm) from male Wistar rats were isolated on their vascular pedicles. Perfusion through an aortic cannula with oxygenated (95% O2, 5% CO2) Krebs solution containing 5% bovine albumin, 5.6 mM glucose, and 25 mM mannitol at 37 degrees C was initiated immediately after interruption of blood flow. The bowel preparations, including the abdominal aorta, were then transferred to a perfusion chamber. Perfusion pressure was maintained by gravity at 40 mm Hg. Flow was measured with an electromagnetic flow probe. The portal vein, together with the lymphatics, drained freely into collection tubes. The bowel lumen was perfused at 0.85 ml/min with isotonic modified Krebs solution containing [14C]polyethylene glycol, and the luminal perfusion pressure was monitored. Luminal effluents were collected through a large-bore outlet tubing. As determined by histology, O2 consumption, vascular reactivity, and mucosal permeability, the preparations were viable for at least 60 min of perfusion. With this model, a vasoconstrictor effect of the alpha 2-adrenoceptor agonist clonidine was documented for the first time in isolated rat bowel.

Animals↗
PubMed1992

Completion thyroidectomy: a critical appraisal.

BACKGROUND: Completion thyroidectomy can most accurately be described as reexploration of the neck to remove the contralateral thyroid lobe. This procedure has commonly been performed when the histopathologic condition of the ipsilateral thyroid lobe reveals papillary or follicular carcinoma of the thyroid. Because of a definitely increased risk of complications with completion thyroidectomy, avoiding its routine use is important. The purpose of this paper is to define the specific indications for completion thyroidectomy. METHODS: Over the past 9 years, we have performed 400 thyroidectomies; the patients ranged in age from 18 to 88 years. Although we have routinely used preoperative needle biopsy and intraoperative frozen section, decisions regarding the extent of thyroidectomy have been based on the gross findings at operation, taking into consideration such prognostic factors as patient age, tumor grade and size, the presence of extracapsular spread or distant metastasis, and associated risk factors. The minimal procedure for solitary thyroid nodule has been lobectomy with isthmusectomy. If the contralateral lobe is grossly normal, lobectomy with isthmusectomy has also been the maximal operation in most of patients. Very few specific indications exist for removal of the opposite lobe. RESULTS: Only three patients underwent completion thyroidectomy. All three patients had aggressive follicular carcinoma requiring radioactive iodine ablation, and all were referred after the initial surgery. We have not performed completion thyroidectomy on any of the patients on whom we initially operated. CONCLUSIONS: The most common indication considered for completion thyroidectomy is a frozen section diagnosis of a benign follicular adenoma that is subsequently changed on permanent pathologic condition to follicular carcinoma based on the presence of capsular and/or vascular invasion. However, if minimal invasion has occurred, no difference exists in survival related to the extent of the thyroidectomy. Local recurrence in the contralateral lobe occurs in less than 10% of the time. Because completion thyroidectomy carries more risks, it should be avoided in most patients when possible. The definitive decision should be made during the initial operation based on gross findings, prognostic factors, and frozen section, and this plan should only be changed to mandate completion thyroidectomy in select circumstances.

Adenocarcinoma↗
PubMed1991

Parathyroid autotransplantation during thyroid surgery.

Permanent hypoparathyroidism is one of the most distressing complications of thyroid surgery. The incidence of this iatrogenic complication varies between 3 and 25 percent among patients undergoing total thyroidectomy. Parathyroid injury may be caused by inadvertent removal of the parathyroids, ligation of the blood supply, or destruction secondary to capsular hematoma. Attention to such technical details as identification of the parathyroids, dissection close to the thyroid gland, preservation of the blood supply to the parathyroids, and avoiding manipulation of parathyroids reduces the incidence of temporary and permanent hypoparathyrodism. However, if the parathyroids are injured, the best method of preserving their function is by autotransplantation. Over the past 7 years we have performed 250 thyroidectomies. An attempt was made to identify and preserve parathyroid gland in each case. Even during lobectomy procedures, the ipsilateral parathyroids were identified and preserved. Whenever any of the parathyroids was devascularized or separated from the surrounding structures, it was autotransplanted into the sternomastoid muscle. The sternomastoid was chosen for autotransplantation rather than forearm muscles to avoid an added incision and because selective measurement of parathormone is not essential in this group of patients. Prior to autotransplantation, confirmation of the nature of the tissue was made by frozen section of a small portion of the parathyroid gland. Parathyroid autotransplantation was performed in 15 instances, even when only one parathyroid was injured. Only one member of this group of 15 patients developed temporary hypoparathyroidism, which disappeared after 4 weeks of calcium supplementation. The remaining patients had an uncomplicated recovery. Autotransplantation of the parathyroid glands should be performed whenever the parathyroid is devascularized or damaged by retraction or hematoma. It is essential for every thyroid surgeon to be familiar with the technique of parathyroid autotransplantation.

Calcium↗
PubMed1991

Subtotal submucosal cricoid resection: an experimental study.

It has generally been considered that the cricoid cartilage is essential for maintaining airway continuity. The purpose of this experimental study was to test this concept by evaluating the effects of subtotal excision of the canine cricoid cartilage. Eight adult mongrel dogs were studied. They received general anesthesia and were intubated. By using a vertical midline incision, the cricoid cartilage was exposed. Subtotal cricoid resection was performed by submucosal dissection; the mucosal continuity was not violated. The resultant defect in the cricoid cartilage was reconstructed with a polytetrafluoroethylene (PTFE) graft which was sutured in place with prolene sutures. All the dogs were extubated immediately after surgery. None required tracheostomy or ventilatory support and none had any respiratory problems during the follow-up period. They were all able to eat soon after surgery. The animals were followed for up to 4 to 6 months and then sacrificed to permit evaluation of the condition of the airway and subglottic space. There was fibrous scarring outside the graft but no evidence of airway narrowing. Despite submucosal fibrosis, the mucosa appeared normal. The data documented that dogs tolerate subtotal cricoid resection very well and develop no subglottic stenosis. The resultant defect in the cricoid cartilage can readily be reconstructed with a PTFE graft.

Animals↗
PubMed1991

An experimental model for the surgical correction of tracheomalacia.

Tracheomalacia may result from large intrathoracic goiters. Due to the chronic compression, particularly within the confines of the thoracic inlet, the tracheal wall weakens, with disintegration of some of the cartilaginous rings. Tracheomalacia can cause acute airway distress, particularly during the post-operative period, and may occasionally result in death. The other major cause of tracheomalacia is related to either prolonged endotracheal intubation or over-inflation of the tracheostomy cuff. While various techniques such as internal stenting, external support devices, tracheostomy, and tracheal resection have been used based on individual circumstances, no one method appears to be perfect. To further study this difficult problem, an experimental model of tracheomalacia was created in eight dogs. Six to seven rings of the tracheal cartilages were dissected submucosally. More than half of the circumference of the tracheal rings was resected. The tracheal walls were reconstructed with polytetrafluoroethylene (PTFE) grafts. The grafts strengthened the tracheal wall without causing luminal constriction. Tracheostomy was not performed on any of the dogs. All dogs tolerated the procedure well and were extubated at the conclusion of the experiment. The dogs were followed for 4 to 6 months and then sacrificed so that the tracheal wall could be examined histologically. There was considerable fibrosis leading to stiff neotrachea. The results of this experimental technique for prosthetic reconstruction to counteract problems simulating tracheomalacia are very encouraging.

Animals↗
PubMed1991

Effect of endothelin-1 and vasoactive intestinal contractor on blood flow and output of vasoactive intestinal polypeptide in the feline colon.

Injection of the structurally related peptides, endothelin-1 and vasoactive intestinal contractor (VIC), into a branch of the superior mesenteric artery in anesthetized cats caused dose-dependent reductions in blood flow in the portal vein and inferior mesenteric artery. The maximum effect occurred after 1 minute and was more prolonged in the portal vein. The effects of the two peptides were not significantly different. The colonic output of vasoactive intestinal polypeptide (VIP) into portal venous blood was decreased significantly by endothelin-1 and VIC, returning to baseline more rapidly than blood flow. When norepinephrine was injected to produce comparable reductions in blood flow, the output of VIP into portal venous blood was not altered significantly. These results suggest that inhibition of output of the vasodilator VIP contributes to the vasoconstrictor effects of endothelin-1 and VIC in the feline colonic vascular bed.

Animals↗
PubMed1991

Role of diagnostic techniques in the initial evaluation of stab wounds to the anterior abdomen, back, and flank.

Despite the widespread availability of firearms, stab wounds to the abdomen, back, and flank continue to account for a significant number of injuries. The proper sequencing of diagnostic modalities in this patient group is constantly undergoing change. We report our experience with these injuries and present a new algorithm for the use of currently available diagnostic procedures. In 1987, 162 patients were seen, 103 with anterior abdominal wounds and 59 with back and flank wounds. Patients with shock, peritonitis, and evisceration were resuscitated and explored. The remainder of the cohort underwent tap and lavage, and patients with a negative study were observed. Patients with back and flank wounds underwent contrast enhanced computerized tomographic enemas (CECTE). Seventeen patients underwent immediate exploration and 108 of the 162 patients were spared exploration. Fifty-four patients were explored with six negative laparotomies. Of the 126 taps and lavages, the false positive rate was zero, and only one patient had a false negative study. Of the 47 CECTE studies, only three were interpreted as an indication for angiography which proved negative, and all patients were safely observed. The overall mortality was 4.3%, including three patients without vital signs on admission and four who expired intraoperatively due to irreversible shock. We concluded that this algorithm can be safely applied to patients with these injuries with a high degree of specificity and sensitivity.

Abdominal Injuries↗
PubMed1991

The adaptive ability of transplanted rat small intestine.

This study was performed to determine the extent to which intestinal transplants undergo functional and morphologic compensation. Animals were studied after 25 days to document how rapidly the changes occurred and after 150 days to establish whether the effects were maintained long term. Lewis isografts and Lewis Brown Norway F1 allograft recipient rats had comparable degrees of morphologic (increased bowel diameter, crypt depth, and villus height) and functional (absorption of 3H-glucose, 14C-maltose, and cyclosporine) compensation. These changes were already present by day 25 and persisted until at least day 150. The results were independent of the loss of extrinsic innervation or the intramuscular administration of cyclosporine (5 mg/kg/day). These observations support the usefulness of segmental intestinal transplantation in the treatment of surgically induced short bowel syndrome.

Animals↗
PubMed1990

Synthesis of prostaglandins I2 and E2 by the canine gallbladder in vitro: studies using a new incubation chamber.

Using a specially designed incubation chamber, differential synthesis and the response to added arachidonic acid (25 mM) and L-alpha-phosphatidylcholine (LAP; 2 mM) was quantified in gallbladders from male and female dogs. Prostaglandin I2 (PGI2) was the predominant prostanoid synthesized, and tissues from females produced much more PGI2 under basal conditions than did gallbladders harvested from male dogs. Addition of arachidonic acid stimulated PGI2 synthesis by almost 100 per cent. Arachidonate-stimulated mucosal and serosal production of PGI2 were (mean(s.e.m.] comparable, 343(178) and 375(89) pg/cm2/min, respectively. Gallbladders from female animals synthesized significantly more PGI2 than did tissue from males. Indomethacin inhibited PGI2 synthesis in a dose-response manner; at 7 x 10(-5) M, prostanoid synthesis was inhibited by greater than 80 per cent. Arachidonic acid did not stimulate prostaglandin E2 (PGE2) production by gallbladder tissue. LAP similarly stimulated PGI2 biosynthesis, but in contrast to the effect of arachidonic acid, the effect was significantly greater in the serosa than the mucosa, 355(107) and 213(59) pg/cm2/min, respectively. LAP also stimulated PGE2 biosynthesis by the canine gallbladder in a pattern very similar to that of PGI2. Based on the differences in response to the two agents added, we conclude that arachidonic acid and L-alpha-phosphatidylcholine stimulate prostaglandin biosynthesis via independent pathways. We advocate the use of the incubation chamber for the assessment of prostanoid biosynthesis by the gallbladder in vitro.

Animals↗
PubMed1990

Accuracy and pitfalls of frozen section during thyroid surgery.

The purpose of this study was to assess the accuracy of frozen sections performed during thyroid surgery and to define any pitfalls they may have. The material includes a series of 190 frozen section examinations of thyroid pathology. The overall accuracy of frozen section in this series was 95%. There were no false positives in our series and false negatives related to only follicular adenomas. In two patients, the report was deferred for permanent slide examination. Nine patients had lesions reported as malignant; however, the distinct cell type was not designated on frozen section. Eight specimens initially reported to have follicular adenoma on frozen section turned out to have angioinvasion or capsular invasion indicative of follicular carcinoma. Minor discrepancies between frozen and permanent sections in the types of benign disease were noted occasionally, but were not clinically significant. There was a discrepancy in the diagnosis of Hashimoto's thyroiditis on three occasions. The major discrepancy in patients with malignant pathology was related to the cell type. The diagnosis of anaplastic thyroid cancer, though suspected, was deferred for permanent sections in all cases. The diagnosis of medullary cancer of thyroid was difficult to make on frozen section. The major problem with frozen section was the diagnosis of follicular adenoma versus carcinoma. The benign diagnosis was changed in eight instances (out of 24 frozen sections) from follicular ademona to follicular carcinoma. Because of this experience, we do not provide the frozen section diagnosis to the patient and we wait until the final diagnosis is available.

Adenocarcinoma↗
PubMed1990

Needle aspiration biopsy in salivary gland lesions.

The value of needle aspiration biopsy in the evaluation and management of salivary gland pathology is controversial. The major reasons for this controversy are the difficulty in cytologic evaluation and the fact that the extent of surgery can be easily defined based on clinical judgement. However, a preoperative diagnosis is helpful in discussions with patients regarding the extent and type of surgery. Apart from the fact that needle biopsy can distinguish benign from malignant conditions, it is also very useful in distinguishing between salivary and other nonsalivary pathology. Over the past 7 1/2 years, we have performed 160 needle aspirations of parotid, submandibular, and submucosal lesions. Adequate specimens for cytologic evaluation were obtained in 155 patients (97%). A total of 84 parotid lesions, 70 submandibular lumps, and 6 submucosal abnormalities were detected. A cytologic diagnosis of benign pathology was made in 120 patients. Twelve patients had lymphoma and the diagnosis was suspected based on needle aspiration. There were 10 patients with tuberculosis and 30 patients with hyperplastic lymph nodes or benign lymphoepithelial disease of the parotid. There were three false-positive and two false-negative reports. No complications such as hematoma, nerve injury, or infection developed. The major difficulty was in distinguishing between malignancy and obstructive sialadenitis in the submandibular region. Needle aspiration was helpful in evaluating lesions in the tail of the parotid and submandibular area. The cytologic distinction between salivary and nonsalivary pathology was useful in planning the appropriate surgery and the extent of surgical resection. From a clinical standpoint, the distinction between benign and malignant salivary and nonsalivary pathology was very helpful. Preoperative diagnosis of Warthin's tumor, lymphoma, or benign lymphoepithelial disease was essential to the correct management of these patients.

Adolescent↗
PubMed1990

Successful segmental intestinal transplantation in enterectomized pigs.

The aim of this study was to determine whether short-segment jejunal allografts maintained the viability and nutritional status of outbred recipient pigs treated with low-dose cyclosporine. The animals were subjected to total small bowel resection (from the ligament of Treitz to the ileocecal valve, approximately 15 m). Short-gut control animals (n = 8) who had no transplant died of malabsorption on day 62.5 +/- 4.1 (mean +/- SEM). Without cyclosporine immunosuppression, recipients (n = 5) of 3 m to 4 m jejunal allografts died of rejection on day 8.8 +/- 0.7. However enterectomized pigs (n = 11) who had segmental jejunal allograft transplants and were treated with cyclosporine (10 mg/kg/day) demonstrated significantly prolonged survival (to day 80.9 +/- 22.3; p less than 0.05). By 180 days after transplant, surviving animals increased their weight by almost 40%. In conclusion short-segment jejunal allografts significantly improved the mortality and morbidity rates from surgically created short bowel syndrome in pigs.

Animals↗
PubMed1990

Effect of transplantation on tissue levels of substance P, vasoactive intestinal polypeptide, and serotonin in rat small intestine.

Denervation of the gut, resulting in altered bowel function, has been viewed as an impediment to the clinical success of small intestinal transplantation. This study examined the effect of complete extrinsic denervation of the jejunum and ileum on tissue levels of VIP, SP, and 5-HT in a rat model of small intestinal transplantation. Orthotopic total small bowel isograft transplants were performed in 18 Lewis inbred rats. Sham operations consisted of occluding the superior mesenteric artery of 18 Lewis rats for 10 minutes to provide comparable degrees of ischemia. Six rats from each group were sacrificed 1, 2, and 4 weeks following transplantation or sham operation. The jejunum and ileum were removed and extracted in acid for measurement of VIP, SP, and 5-HT by radioimmunoassay. There were no statistically significant differences in the jejunal or ileal content of VIP or 5-HT or the jejunal content of SP between the transplant and sham groups. An initial decrease in ileal SP content at 1 week following transplantation was no longer evident by the fourth week. We conclude that the extrinsic denervation of small intestinal transplantation has minimal effects on the intestinal content of VIP, SP, and 5-HT and should not significantly affect physiologic function controlled by these gastrointestinal hormones.

Animals↗
PubMed1990

VIP antagonist [N-Ac-Tyr1,D-Phe2]-GRF-(1-29)-NH2: an inhibitor of vasodilation in the feline colon.

The effect of the vasoactive intestinal polypeptide (VIP) antagonist [N-Ac-Tyr1,D-Phe2]-GRF-(1-29)-NH2 on pelvic nerve-induced colonic vasodilation and VIP release was investigated in chloralose-anesthetized cats. VIP antagonist (10 and 50 nmol/kg in saline) or saline alone was injected into a branch of the superior mesenteric artery immediately before bilateral pelvic nerve stimulation. The increase in conductance in the inferior mesenteric artery during pelvic nerve stimulation was reduced in an apparently dose-dependent fashion by the VIP antagonist (by 35 +/- 10 and 42 +/- 9%, respectively) compared with the pelvic nerve-induced increase in conductance after injection of saline alone. Injection of the VIP antagonist (50 nmol/kg) did not alter conductance in the absence of pelvic nerve stimulation. VIP was released into portal venous blood during pelvic nerve stimulation in the presence of the antagonist (from 103 +/- 29 to 165 +/- 45 pmol/l). This was not significantly different from release in the presence of saline. The effect of the VIP antagonist (10 nmol.kg-1.min-1) on inferior mesenteric arterial vasodilation induced by exogenous VIP was also quantitated. The increase in conductance after VIP injection (0.2 nmol/kg) was significantly reduced when accompanied by simultaneous infusion of the VIP antagonist (by 54 +/- 6%) compared with the increase in conductance during simultaneous infusion of saline. We conclude that [N-Ac-Tyr1,D-Phe2]-GRF-(1-29)-NH2 is an inhibitor of pelvic nerve-induced vasodilation in the feline colon and does not act by modulating VIP release.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Intraoperative decision making during thyroid surgery based on the results of preoperative needle biopsy and frozen section.

Prognostic factors in well-differentiated thyroid cancer are age of the patient and grade, size, distant metastasis, and extracapsular spread of the disease. However, the surgeon is often not sure about the pathologic diagnosis of thyroid nodules. The accuracy of preoperative studies, such as ultrasonography and thyroid scanning, is limited. The most cost-effective test is fine-needle aspiration, the accuracy of which exceeds 80% in most series. However, a large group of nodules exist for which aspiration cytologic studies are considered to be either suspicious or indeterminate. The decision about the extent of thyroidectomy may be difficult in these patients. Intraoperative frozen section may help the surgeon to distinguish benign from malignant lesions, but as in fine-needle aspiration, the major problem is the distinction between follicular adenoma and follicular carcinoma. The frozen section diagnosis of follicular adenoma was changed to follicular carcinoma in one third of the cases (13 of 38 cases). The decision about the extent of thyroidectomy in patients with follicular adenomas was based on other prognostic factors, such as age and sex of the patient and the size of the nodule. The accuracy of frozen section diagnosis was 95%. Our experience suggests that decisions regarding the extent of thyroidectomy can best be made by preoperative fine-needle aspiration with confirmation by frozen section diagnosis in equivocal cases.

Adenocarcinoma↗
PubMed1990

The effects of short-term ethanol exposure on the canine jejunal handling of calcium and glucose.

The effects of ethanol on simultaneous jejunal handling of calcium and glucose were studied in long-term canine jejunal Thirty-Vella loops. The loops were perfused intraluminally in a random sequence with physiologic buffer, buffer containing 3.5% ethanol, and buffer containing 7% ethanol. The addition of 3.5% or 7% ethanol to the buffer reduced the net absorption of glucose by 13% and 26%, respectively. The addition of 7% but not 3.5% ethanol significantly increased the net secretion of calcium (168% of basal). In contrast, luminal perfusion with ethanol did not significantly alter intestinal handling of water, sodium, or potassium. Serum calcium and glucose levels were similarly unaffected by the ethanol perfusion. Mean serum ethanol levels were all less than 10 mg/dl. We conclude that intraluminal ethanol has a significant effect on the jejunal handling of glucose and calcium, and this effect is not dependent on systemic intoxication.

Animals↗