Hypoxia-induced sympathetic inhibition of the fetal plasma insulin response to hyperglycemia.

Large-for-delivery date babies, considered characteristic of diabetic pregnancy, are believed to result from fetal hyperinsulinemia. Paradoxically, infant birth weights tend to be low-for-delivery date in mothers with more severe diabetes. We tested the hypothesis that hypoxemia in such fetuses leads to sympathoadrenal stimulation and inhibition of insulin secretion; and, thus, produces a net reduction in the growth-promoting effects. Fetal sheep were prepared with chronic peripheral and adrenal cannulas. Fetal blood gases, lactate, norepinephrine, and epinephrine secretion rates; and plasma norepinephrine, glucose, and immunoreactive insulin concentrations were determined at 30-min intervals during a 2-h baseline period and a 4-h period of hyperglycemia divided into 2-h segments of hypoxemia (with and without alpha-blockade) and hyperoxia. Hypoxemia-hyperoxia sequences were varied randomly. Well-oxygenated fetuses responded to a threefold increase in glucose with a sixfold increase in plasma immunoreactive insulin. With hypoxemia, norepinephrine and epinephrine secretion were elevated and the insulin response was blocked. With hypoxemia and phentolamine blockade, the insulin response was enhanced with a 10-fold increase above baseline. In severe maternal diabetes with vascular disease or with poor control and very high glucose levels, the fetus is likely to be relatively hypoxemic. Our experiments suggest that in this situation, the fetal insulin response to hyperglycemia will be attenuated; this effect is mediated, at least partly, through sympathoadrenal stimulation.

Adrenal secretion of glucocorticoids during hypoxemia in fetal sheep.

This work was undertaken to investigate the fetal adrenal corticoid secretory response to hypoxic stress in late gestation. Experiments were performed in two groups of fetal sheep of different gestational ages, group I, 129-132 (mean, 130) days and group II, 135-139 (mean, 136) days. Fetuses were prepared with chronic adrenal cannulas as well as peripheral arterial and venous catheters. With the fetus at rest and after 7, 9, 11 and, in some instances, 30 and 60 min of hypoxia (maternal FIO2 10%), precisely timed (2 min) samples of adrenal effluent were collected for determination of cortisol (F) and corticosterone (B) secretion rates. Peripheral samples were obtained intermittently for blood gas and lactate determinations. Resting corticoid secretory rates were highly variable, suggesting an episodic secretory pattern. Corticoid secretory responses to hypoxemia were significantly elevated at 7-11 min, peaked at 30 min, and remained stable at 60 min. Specifically, in group I, F secretion increased from a baseline value of 37 +/- 19 ng/min to a peak hypoxemic response of 376 +/- 80 ng/min; B secretion increased from 6 +/- 4 to 170 +/- 32 ng/min. In group II, F secretion increased from 99 +/- 20 to 653 +/- 107 ng/min; B secretion increased from 12 +/- 5 to 200 +/- 28 ng/min. When related to adrenal gland weight, there was no difference between F secretory responses in groups I and II, whereas relative B secretory responses were lower in group II than in group I at 9 and 11 min of hypoxemia. We conclude that the 129-139 day sheep fetal adrenal cortex is highly sensitive to hypoxic stress with the effect presumably mediated by elevated levels of endogenous ACTH. The B stress response decreases as gestational age advances from the 129-132 day range to 135-139 days.

Adrenal secretion of catecholamines during hypoxemia in fetal lambs.

A new method for quantifying adrenal secretory function in chronically catheterized fetal lambs was developed. This preparation included insertion of a catheter distally into the fetal left renal vein and placement of a remotely operated, hydraulically controlled choker around the renal vein at its junction with the vena cava. With the choker open, adrenal venous blood flowed into the renal vein and then into the vena cava. With the choker closed, adrenal blood flowed into the catheter so that timed samples of adrenal venous effluent could be obtained. With this technique, left adrenal secretory rates of norepinephrine and epinephrine were determined across a spectrum of oxygen concentrations in five near-term fetal lambs. There was a rapid rise in norepinephrine secretion after induction of hypoxemia. Maximum secretory rates occurred at about 5 min, concomitantly with the lowest attained fetal arterial partial pressure of oxygen (PO2s). There was an inverse exponential relation between these catecholamine secretion rates and fetal arterial PO2 (P less than 0.001). Norepinephrine secretion appeared to increase in response to lesser degrees of hypoxemia than did epinephrine, although a longer time delay between stimulation and epinephrine response may have been a factor. Overall, norepinephrine secretion was greater than that of epinephrine. The ratios of norepinephrine to epinephrine in individual adrenal samples varied considerably and in some instances were less than one. These ratios did not correlate significantly with the degree of hypoxemia. During 25 min of a relatively steady state of hypoxemia, norepinephrine secretion declined markedly after about 5 min, although it remained above control levels throughout. Epinephrine secretion rose more gradually but then was relatively stable during the remaining period of hypoxemia.

Analysis of cell type and radiographic presentation as predictors of the clinical course of patients with bronchioalveolar cell carcinoma.

STUDY OBJECTIVES: Bronchioloalveolar carcinoma is a primary lung neoplasm of variable histopathologic, radiologic, and clinical expression. There are three cell types described in bronchioloalveolar carcinoma: Clara cells, mucin-producing cells, and alveolar type II epithelial cells. It is unclear whether these three tumor cell types are associated with a specific radiologic presentation and clinical course. In this study, we investigated whether tumor cell type, identified by transmission electron microscopy, correlated with a specific radiologic pattern, and whether tumor cell type or radiologic presentation correlated with the patient's clinical course and outcome. DESIGN: Transmission electron microscopy was used to restudy tissue blocks from the original surgical histopathologic specimens in 54 patients with primary bronchioloalveolar carcinoma diagnosed over a 10-year period (1980 to 1990). The pretreatment radiographs were reviewed in each case, and the first chest radiograph obtained at the time of the discovery of the tumor in each patient was compared with the results of the ultrastructural study. The medical records of each patient were examined to obtain pertinent radiologic, clinical, and patient outcome information. MEASUREMENT AND RESULTS: There were 32 Clara cell tumors, 10 mucin-producing cell tumors, and 1 alveolar type II epithelial cell tumor in this series. Eleven additional tumors had mixtures of two or more cell types. No statistically significant relationship was detected between tumor cell type and radiologic presentation or patient mortality pattern. There was increased mortality among patients who presented radiologically with segmental, lobar, multifocal, or diffuse disease compared with those patients exhibiting a solitary pulmonary nodule at presentation. CONCLUSION: Radiologic presentation, rather than tumor cell type, provides prognostic information that aids in predicting patient outcome.

Management of esophageal injuries.

A multiinstitutional study of 39 esophageal injuries treated between 1982 and 1988 and a comprehensive review of the literature revealed an unacceptably high mortality rate of more than 20%. Results of the current study indicated that prompt diagnosis and aggressive surgical management of esophageal injuries could improve the outcome and lower the associated mortality. The clinical experience and literature review allowed us to elaborate caveats and principles that, if adhered to, should improve the outcome in esophageal injuries.

Bronchoalveolar cell carcinoma of the lung.

A multivariable analysis was performed of all patients registered and confirmed to have bronchoalveolar cell carcinoma of the lung in the Tumor Registry of Thomas Jefferson University Hospital between 1969 and 1983. These 122 patients were reviewed for age, sex, smoking history, occupational exposure, symptoms, radiographic findings, methods of diagnosis, clinical and pathologic staging, methods of treatment, survival, and complications of treatment. No correlation could be found in this series between a patient's age, sex, smoking history, or occupational exposure and the incidence or outcome of the disease. Seventy-one of the 122 patients in this series were asymptomatic, and the carcinoma was discovered in them by routine chest roentgenogram. Of these asymptomatic patients, 50 were seen with pathologic stage I disease. Of the 51 symptomatic patients, 32 (65%) were seen with stage IIIm0 or IIIm1 disease. Despite medical evaluations, 77% of the T1 and T2 lesions required thoracotomy for diagnosis. The overall five-year survival rate was 42.3%, ranging from 75% for those with stage I disease to 8.7% for those with stage IIIm1 disease.

Rounded atelectasis: a pulmonary pseudotumor.

Rounded atelectasis is a benign entity that is often misinterpreted as a pulmonary neoplasm. The roentgenologic appearance of a mass is due to an infolding of atelectatic tissue intermingled with pleura, blood vessels, and bronchi. Rounded atelectasis is usually asymptomatic and is commonly associated with chronic pleural disease or pleural effusions. The distinctive radiologic features include a rounded, pleural-based opacity associated with adjacent pleural thickening and volume loss of the affected lobe. The pathognomonic sign is the "comet tail" that results from the crowding of vessels and bronchi as they enter the atelectatic region. Many authors consider this constellation of findings diagnostic. Rounded atelectasis usually remains stable over time; however, slow growth, as well as diminution in size, has been described. A retrospective analysis revealed 7 cases of rounded atelectasis at our institution over a 9-year period. Three were operated on to exclude malignancy, one was confirmed at operation performed for other reasons, and 3 were followed up expectantly. We conclude that recognition of this entity and its radiologic features can be diagnostic and render further workup, including thoracotomy, unnecessary.

The utility of sestamibi scanning in the operative management of patients with primary hyperparathyroidism.

BACKGROUND: The role of imaging studies before parathyroidectomy has been extensively debated and recent advances in unilateral parathyroidectomy intensify this controversy. The purpose of this study was to review the parathyroidectomy experience of a single surgeon, looking at the role of sestamibi scans and a standard postoperative care regimen. STUDY DESIGN: Retrospective review of office and hospital charts was completed on 90 patients with primary hyperparathyroidism who underwent parathyroidectomy from 1991 to 1998. Patient workup and outcomes were noted, as were results of preoperative imaging. True-positive scans visualized an abnormality ipsilateral to the adenoma found at operation. Statistics were performed using nonparametric testing and Student's t-test. RESULTS: There were 21 male and 69 female patients, with an average age of 54 years (range 29 to 81). There were zero mortalities, three morbidities (3.3%), and three patients who had persistent hypercalcemia, yielding a 96.7% success rate. Sixty-seven patients underwent preoperative sestamibi scanning, with a sensitivity of 74% and positive predictive value of 89%. Operative time in imaged patients averaged 103 +/- 49.9 minutes versus 121.5 +/- 85.9 minutes for patients without sestamibi scans. Operating time differences were not statistically significant and a preoperative sestamibi scan did not affect the success of parathyroidectomy. Discharge on postoperative day 1 was accomplished in 80% of patients and 13% were discharged the next day. There was no morbidity from hypocalcemia. CONCLUSIONS: A preoperative sestamibi scan does not improve efficacy or decrease operating time for primary hyperparathyroidism when bilateral neck exploration is performed. A postoperative care protocol including oral calcium and vitamin D supplementation allows the majority of patients to be discharged on postoperative day 1 with excellent results.

Intrathoracic chordoma presenting as a posterior superior mediastinal tumor.

A case of thoracic chordoma successfully treated with surgical excision is reported and described. Thoracic chordomata presenting as posterior superior mediastinal tumors occur infrequently and may be highly malignant lesions. Early radical surgery through thoracotomy provide the best hope of cure, and radiation offers only temporary regression of tumor.

The use of autografts for vertebral body replacement of the thoracic and lumbar spine.

Thirty-seven patients with fractures of the thoracic or lumbar spine underwent anterior corpectomy (partial or complete) and vertebral body replacement for either destructive lesions from tumor or infection (13 patients) or trauma (24 patients). The vertebral bodies were replaced using either rib (12 patients) or tricortical iliac crest (25 patients) autografts. The Dunn device was utilized in conjunction with the autografts in 19 patients. Posterior stabilization was used in five patients; three prior to anterior stabilization and two after anterior stabilization. Within 2 weeks of the operative procedure, all patients began walking or sitting. Of the 37 patients, 21 with incomplete neurologic deficits improved, and 10 of those went onto complete recovery. Of the 27 patients who have been followed for a minimum of 1 year, 25 have obtained solid fusions, one developed a pseudarthrosis that required regrafting, and one had a delayed union prior to death from metastatic disease. There were two deaths in the immediate postoperative period and three deaths in the first six postoperative wounds due to metastatic disease. The purpose of this study is to present a consecutive series of patients who have undergone corpectomy and vertebral body replacement as well as to define the adequacy of stabilization.

Cause and current management of reoperative hyperparathyroidism.

We reviewed 137 cases of hyperparathyroidism followed for 6-72 months to determine the reasons for failure and to outline the successful management of reoperative hyperparathyroidism. Of 127 patients treated initially at Thomas Jefferson University Hospital, three required reoperation (2.4%) and 10 were referred with recurrent or persistent hyperparathyroidism. Reasons for failure were a missed gland in eight cases (62%), an ectopic gland in two cases (15%), supernumerary glands in two cases (15%), and malignant degeneration of an autotransplant in one case (8%). One patient had shortterm hypoparathyroidism requiring vitamin D supplementation (5.6%), but there were no injuries to the recurrent laryngeal nerves. We conclude that adequate knowledge of the location of normal and ectopic glands with meticulous search will reduce most reoperations, and, with identification of all four glands and routine cervical thymectomy in multigland disease, the rate should be less than 5 per cent. Patients requiring reoperation should undergo noninvasive localization studies and, if equivocal, selective venous sampling for parathyroid hormone. The major complication rate should be less than 10 per cent.

Surgical treatment of secondary hyperparathyroidism in patients with chronic renal failure by sub-total parathyroidectomy.

The majority of patients with secondary hyperparathyroidism caused by chronic renal insufficiency are successfully managed medically. However, approximately 5-10 per cent develop refractory symptoms such as bone pain and pruritus requiring palliative surgical treatment. We present a series of 16 consecutive patients who were managed with sub-total parathyroidectomy over a 6-year period. With follow-up of 12-60 months, there were no operative mortalities or significant perioperative morbidities. All patients had significant improvement or resolution of their symptoms. All had biochemical improvement with reductions in their serum calcium and parathormone levels. No patients have required re-exploration for persistent or recurrent hyperparathyroidism, and there have been no cases of permanent hypoparathyroidism. We feel that sub-total parathyroidectomy remains the optimal treatment for refractory secondary hyperparathyroidism. It offers several advantages over total parathyroidectomy with autotransplantation.

Bronchial atresia with relapsing pulmonary infection in a middle-aged man.

Congenital bronchial atresia (CBA) is a rare disorder, first reported in 1953. Less than 100 cases are reported in the literature, mostly in young, asymptomatic male patients with involvement of the apical-posterior segment of the left upper lobe. Patients may complain of fever, cough, or shortness of breath, symptoms that result from post-obstructive, sometimes recurrent, infections. Chest radiography and computed tomography reveal a tubular branching density representing mucus impaction or mucocele with surrounding focal hyperinflation. Surgical excision is reserved for symptomatic cases. We report an unusual case of CBA in a middle-aged man with a history of relapsing infections, who was found to have an atretic superior segment of the left lower lobe, with surrounding areas of organizing pneumonia.

Congenital bronchoesophageal fistula in the adult.

Congenital bronchoesophageal fistulas usually present in infants and may occur with or without esophageal atresia. Twenty cases of congenital bronchoesophageal fistula in adults have been reported in the English literature. Another case of this rare developmental anomaly is presented here. The radiographic, endoscopic, surgical, and pathologic findings are discussed with a review of the literature.

Role of thoracoscopy and preoperative localization procedures in the diagnosis and management of pulmonary pathology.

Video-assisted thoracic surgery is an important component of modern thoracic surgery, providing a safe, less invasive alternative to open thoracotomy in the evaluation of pleural, mediastinal, and parenchymal pathology. Advancements in endoscopic techniques and video-optics have permitted greater visualization of the thoracic cavity and allowed limited pulmonary resections with significantly reduced postoperative morbidity. Thoracoscopy is indicated for diagnosis of intrathoracic pathology when usual methods of diagnosis, including fine-needle aspiration and transbronchial biopsy, are inconclusive. The diagnostic accuracy of video-assisted thoracic surgery approaches 100%. Increasingly, the indications for thoracoscopy include therapeutic resections of pulmonary nodules in cases of limited lung metastases and bronchogenic carcinoma when pulmonary function is poor. Successful diagnostic and therapeutic resection by thoracoscopy requires intraoperative localization of the lesion within the collapsed lung. The indications and methods of thoracoscopic surgery and preoperative localization are discussed.

Dual tracer imaging for localization of parathyroid lesions.

During the period from July 1983 through October 1984, a group of 38 patients with elevated serum calcium, parathormone (PTH) and/or clinical suspicion of hyperparathyroidism were studied by TI-201 Tc-99m dual tracer parathyroid imaging (DTPI). Seventeen of 18 parathyroid lesions were identified correctly. There was one false-negative, and the size of the adenoma missed by DTPI was less than 1.0 cm in diameter (1.0 x 0.5 x 0.2). There was one true-negative case. The other fifteen with negative scans are being followed clinically. Because of the small population studied, statistical analysis was not ascertained. However, this simple, noninvasive procedure has become a very useful diagnostic tool for the detection and localization of parathyroid lesions causing hyperparathyroidism, and the DTPI should be used in conjunction with ultrasonography and CT scanning in the preoperative evaluation in primary and secondary hyperparathyroidism.