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Biomedical subjects

J D Cooper

Publications and source records attributed to J D Cooper.

At least 325 records · Page 18Linked to original sources
PubMed1980

Bronchial carcinoid tumors: twenty years' experience.

We reviewed 69 patients with documented carcinoid tumors, 67 of whom had resectable disease. Operations included nine pneumonectomies, 31 lobectomies, 12 bilobectomies, five segmental resections, and 10 sleeve resections. Follow-up on 65 patients reveals 40 surviving beyond 5 years and 13 beyond 20 years since resection. There were no operative deaths and only one recurrence (local) that was subsequently successfully resected. Twenty patients had had recurrent unifocal pneumonitis or hemoptysis for up to 5 years prior to diagnosis. Two patients had the carcinoid syndrome. Biopsy was performed on 23 tumors and resulted in "moderate-to-severe" hemorrhage in six cases. Lymphatic spread was present in seven cases. All seven are alive and free of disease, six of whom have been followed from 5 to 24 years. Diseased resection margins were present in two cases, with both surviving 20 years after resection. All 10 sleeve resections were performed more than 5 years ago. We conclude that carcinoid tumors carry a favorable prognosis upon resection, even when intrathoracic lymphatic metastases are present and are resected. Lung-sparing resections including sleeve resections should be utilized. Recurrent pneumonia or hemoptysis or both requires diligent investigation. Biopsy of the tumors may be performed with care.

Bronchial Neoplasms↗
PubMed1980

Lung abscess: surgical implications.

The management of lung abscess continues to challenge both physicians and surgeons. The experience at the Toronto General Hospital over a 50-year period (1928 to 1975) has been analysed to define the challenge and to clarify current recommendations for treatment. The 413 patients studied were divided into three sequential chronologic groups that illustrate the initial impact of antibiotic therapy and later appreciation of the pathogenetic importance of aspiration and anaerobic infection. Although cure rates increased dramatically (from 30 to 61%) between 1936 and 1954 with the advent of antibiotics and the decrease in mortality was equally striking (from 47% to 21%), the recent statistics are not as encouraging. In the current period (1962 to 1975), the cure rate with medical treatment has risen from 61% to 73%, and with surgical therapy from 81% to 89%. Unfortunately, the overall mortality has increased from 12% to 25%. The mortality with medical treatment has increased from 10% to 27% but, in contrast, the surgical mortality continues to decrease (14% to 11%). The increased mortality with medical treatment is important. Prolonged antibiotic therapy is frequently necessary, but when resolution is not progressing or when complications ensue, operation must not be delayed.

Adult↗
PubMed1980

Treatment of achalasia: esophagomyotomy with antireflux procedure.

The results of Heller myotomy with Belsey fundoplication in the treatment of 32 patients with achalasia is reviewed. Eighteen who received no previous surgical treatment had good to excellent results. Fourteen patients who had undergone previous Heller myotomy without an antireflux procedure required further surgical treatment. Inadequate myotomy and reflux esophagitis were the causes of failure. In this group four patients who were treated by myotomy, Collis gastroplasty and the Belsey procedure still failed to achieve good to excellent results. The authors conclude that gastroplasty is contraindicated in patients with achalasia.

Adolescent↗
PubMed1979

Biocompatibility of standard and silica-free silicone rubber membrane oxygenators.

Spiral coil membrane oxygenators made from either standard silicone rubber or silica-free silicone rubber were compared using three priming techniques. Standard priming, carbon dioxide priming, and denucleation priming were employed with each type of device. Four-hour venovenous membrane oxygenator perfusions were carried out on awake sheep anticoagulated with heparin. Virtually no differences were observed in any parameters measured between standard silicone rubber and filler-free silicone rubber membranes. Significantly greater platelet losses occurred during the first hour of perfusion with standard priming and with carbon dioxide priming than with denucleation priming, using either type of membrane. These experiments demonstrate that denucleation priming reduces platelet losses during extracorporeal membrane oxygenator perfusion, but that the use of filler-free silicone rubber does not improve the biocompatibility of the membrane.

Animals↗
PubMed1979

Dementia, renal failure, and brain aluminum.

Dialysis dementia is a progressive and usually fatal neurologic syndrome occurring in patients on chronic hemodialysis. These patients may also have elevated levels of aluminum (Al+3) in the cerebral cortex. Possible relations between brain Al+3, increased Al+3 intake, and dementia were evaluated. Studies were done in seven groups of patients and five groups of experimental animals. In both normal dogs and rats and those with renal failure, oral Al+3 loading (Al[OH]3), resulted in significant increases of brain Al+3 (P less than 0.01). In patients with renal failure, who were neither demented nor treated with dialysis, brain Al+3 was more than seven times normal (P less than 0.01), whereas in patients with dialysis dementia, mean brain Al+3 was more than 15 times normal. However, the two groups were not significantly different. Brain Al+3 was also significantly elevated in patients who had either metastatic cancer or hepatic coma. Apparently brain Al+3 can be elevated as a consequence of Al+3 loading, renal failure, and abnormalities of the blood-brain barrier. It is most likely that dialysis dementia has multifactoral causation and is probably not caused by elevated brain content of Al+3 alone.

Acute Kidney Injury↗
PubMed1979

Sleeve lobectomy for carcinoma of the lung.

Sleeve lobectomy for non-oat cell carcinoma involving a major bronchus preserves functioning lung tissue and, in carefully selected patients, provides long-term survival comparable to pneumonectomy. Seventy patients underwent sleeve lobectomy between 1967 and 1978. Twenty-seven patients were considered compromised (Group I) because they had severe respiratory impairment which contraindicated pneumonectomy. Forty-three patients were considered uncompromised (Group 2) and underwent elective sleeve lobectomy. Seventy patients with a similar non-oat cell carcinoma involving the proximal bronchi underwent pneumonectomy (Group 3) during this period. Perioperative complications occurred more frequently in Group 1 (59%) than in Group 2 (21%) or Group 3 (23%). Both periopeative mortality rate and the incidence of bronchial disruption (bronchovascular and bronchopleural fistulas) were higher in Group I (19% and 22%) than in Group 2 (9% and 5%) or Group 3 (3% and 7%). Survival depended primarily on the surgeon's ability to perform a complete resection of the tumor. An incomplete resection resulted when tumor was found in the highest lymph node or in the last bronchial resection margin when paraffin sections were reviewed. The 5 year survival rate was 18% for compromised patients (Group 1) who underwent complete resection, and there were no survivors among patients undergoing incomplete resections. Uncompromised patients ( Group 2) had a 5 year survival rate of36% with complete and 12% with incomplete resections. Pneumonectomy patients (Group 3) had a 64% 5 year survival rate with a complete resection and 16% with an incomplete resection. The stage of the disease at the time of operation had a profound effect on the survivail. There was no difference inthe 5 and 8 year survival rates between uncompromised patients undergoing sleeve resection ( Group 2) and patients undergoing peneumonectomy (Group 3) for comparable stage of their disease. A careful pre- and postoperative functional assessment revealed that pulmonary performance was improved in 44% of Group 1, 63% of Group 2, and only 14% of Group 3 patients. Patients wiht impaired pulmonary reserve underwent sleeve lobectomy with an adequate disease-free interval when complete tumor excision was possible. Uncompromised patients whose extensive disease required incomplete resection had palliation by sleeve lobectomy equivalent to that by pneumonectomy. When complete t-mor resection was possible, patients with uncompromised pulmonary reserve had a perioperative complication rate and long-term survival equivalent to that of pneumonectomy while preserving pulmonary parenchyma, which permitted an improvement in postoperative pulmonary performance.

Adenocarcinoma↗
PubMed1978

Extended indications for median sternotomy in patients requiring pulmonary resection.

We have employed median sternotomy in 9 patients for resection of both benign and malignant lung lesions. The most frequent use of this approach was for bilateral wedge resection, though unilateral resection was done in 2 patients. Our experience supports the previously documented usefulness of median sternotomy for minor bilateral resections and suggests that more complex pulmonary resections are possible when an appropriate indication exists. We compared the effects of median sternotomy with those of lateral thoracotomy on postoperative vital capacity and peak airway flow. Both incisions results in a marked loss of measured lung function, but recovery occurs notably sooner after median sternotomy than ater lateral thoracotomy.

Adult↗
PubMed1978

Microbubble elimination during priming improves biocompatibility of membrane oxygenators.

We tested the hypothesis that platelet loss following blood contact with foreign materials is partly related to the presence of microbubbles of gas (gas nuclei) trapped in surface defects on the membrane material. Extracorporeal membrane oxygenator perfusions were conducted in two groups of sheep, with use of standard priming techniques for the oxygenator in one group and a new vacuum priming technique in the other group. The vacuum priming technique was developed to eliminate gas nuclei from the oxygenator surface. With denucleation priming, platelet loss during perfusion was markedly reduced, as was thrombus formation on the membrane surface. The platelet particle-size distribution curve showed a shift consistent with platelet aggregation with the standard priming technique but not with the vacuum priming technique. We conclude that the elimination of trapped gas nuclei from the membrane surface during priming reduces the initial interaction between blood elements and the foreign surface.

Animals↗
PubMed1978

Neurodiagnostic abnormalities in patients with acute renal failure.

Neurological abnormalities are a major cause of morbidity in patients with renal failure. The pathophysiology of these neurological changes is unclear, and the effects on them of dialysis and return of renal function have not been well studied. Studies were done in 31 patients who had acute renal failure (ARF), all of whom were either treated with dialysis within 5 days or did not survive. Studies on these patients included the electroencephalogram (EEG), motor nerve conduction velocity, and plasma Ca(++) and parathyroid hormone (PTH) levels. Studies were done at the time ARF was diagnosed, after stabilization on dialysis, during the diuretic phase of ARF, and 3 mo after recovery from ARF. In 16 patients with acute or chronic renal failure who did not survive and in nine patients without renal disease who died, measurements were made in brain of content of Na(+), K(+), Cl(-), Ca(++), Mg(++), and water. In patients with ARF for less than 48 h, despite the fact that there were only modest increases in plasma urea and creatinine, there were striking abnormalities in the EEG. The percent EEG power < 5 Hz+/-SE was 41+/-8% (normal = 2+/-1%), whereas the percent of frequencies > 9 Hz was only 22+/-6% (normal = 62+/-3%). These changes were unaffected by dialysis, but became normal with return of renal function and remained normal at 3 mo follow-up. The motor nerve conduction velocity was unaffected by either ARF or dialysis. In patients with ARF, the brain Ca(++) was 46.5+/-3.2 meq/kg dry wt, almost twice the normal value of 26.9+/-1.0 meq/kg dry wt (P < 0.001). The plasma PTH level was 3.2+/-0.6 ng/ml (normal < 1.5 ng/ml, P < 0.01). The increased brain Ca(++) was not related to an increased plasma (Ca(++)) (PO(4) (---)) product (r(2) = 0.14, P > 0.05). There was a small but significant decrement in brain Na(+) (P < 0.05), but brain water, K(+), and Mg(++) were unaffected by ARF.Thus, in patients with ARF for less than 48 h, the EEG is grossly abnormal and there are elevated levels of PTH in plasma. The PTH appears to have a direct effect on the brain, resulting in an increased brain Ca(++) content. The EEG abnormalities are unaffected by dialysis, but they become normal with return of renal function and remain normal after 3 mo follow-up. Thus, PTH may be a major uremic toxin, demonstrating evidence for central nervous system toxicity when there are only minimal abnormalities of other biochemical markers of ARF.

Acute Kidney Injury↗
PubMed1978

Symposium on intensive care: 4. Respiratory failure.

Patients requiring respiratory support may have normal lungs but inadequate ventilation, or they may suffer from defective pulmonary gas exchange despite adequate ventilation. In the first group some form of mechanical ventilatory support is called for, either pressure-cycled or volume-cycled, used first with an endotracheal tube and only later with a tracheostomy. Weaning the patient from the apparatus requires special care. In cases of pulmonary insufficiency the use of positive end-expiratory pressure has been a major advance. Hemoglobin concentration, cardiac output and renal function must receive attention. Open lung biopsy is of the greatest value when the diagnosis is open to question. Resort to a membrane oxygenator to provide extracorporeal oxygenation of blood can sustain for a time the patient in whom hypoxia is critical in degree.

Adult↗
PubMed1978

Extracorporeal membrane oxygenator support for human lung transplantation.

Extracorporeal membrane oxygenator (ECMO) support was provided for a 19-year-old boy undergoing right lung transplantation. Perfusion was begun several hours prior to transplant, to correct profound hypercapnia. After the operation, ECMO was required because of inadequate gas exchange by the transplanted lung. Perfusion was continued for a total of 96 hours. During this time, the temporary malfunction of the transplanted lung owing to the reimplantation response reversed, and the patient was successfully removed from the oxygenator and subsequently weaned from the ventilator. He died on the eighteenth postoperative day of bronchial dehiscence. ECMO support appears to be a feasible means of supporting patients during lung transplantation and during the period of reversible lung malfunction that may occur in the early postoperative period.

Adult↗
PubMed1977

Trachea-innominate artery fistula: successful management of 3 consecutive patients.

Trachea-innominate artery fistula is an uncommon but frequently fatal complication of tracheostomy. Three successive patients who developed this complication while receiving ventilatory assistance through a tracheostomy tube were successfully managed, with long-term survival. Bleeding was controlled by direct digital pressure on the innominate artery or by hyperinflation of the balloon cuff of the tracheostomy tube. In 2 patients, replacement of the tracheostomy tube with an orotracheal tube improved direct access to the innominate artery for digital compression. Late follow-up examination of the right carotid circulation revealed complete reversal of flow in the right internal and common carotid arteries in the 2 patients studied.

Adolescent↗