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Biomedical subjects

H Shennib

Publications and source records attributed to H Shennib.

At least 91 records · Page 5Linked to original sources
PubMed1990

Early gastric cancer: is it a distinct clinical entity?

Of 199 patients with gastric cancer seen at The Montreal General Hospital between 1970 and 1981, 104 were considered to have had a curative resection, and 26 of these were early gastric cancers (EGC). The authors compared early gastric cancers with advanced, but resectable, gastric cancers to determine whether EGC is a distinct entity or a stage in the progressive evolution of gastric cancer. They found that depth of invasion was the primary determinant of outcome, but that there was no discrete cut-off point between the depth of invasion associated with early and with advanced gastric cancers. The pathological features normally associated with a favourable prognosis in gastric cancer, such as absence of lymph-node metastases, an expanding growth pattern, intestinal metaplasia, and well-differentiated histologic features correlated highly with depth of invasion but did not appear to change abruptly between EGC and advanced resectable lesions. The authors conclude that EGC is not a distinct pathological or clinical entity but a stage in the progressive growth of gastric cancer.

Adult↗
PubMed1990

Endoscopic guided percutaneous tracheostomy: early results of a consecutive trial.

Percutaneous tracheostomy is increasingly being used for patients needing prolonged ventilatory support. The purpose of this study was to assess the feasibility of widespread application of endoscopic guided percutaneous tracheostomy. Sixty-one consecutive ICU patients requiring prolonged mechanical ventilation underwent bedside endoscopic guided percutaneous tracheostomy. Using a modified Ciaglia technique, a #6-10 tracheostomy tube was introduced between the second and third tracheal rings. Bronchoscopic transillumination facilitated identification of the appropriate tracheostomy site, and verified satisfactory placement of dilators and tracheostomy tube. There was one procedure-related death due to arrhythmia. Procedure-related complications included (n = 7): bleeding (controlled with local pressure), two infections, two cuff tears, and two obstructions of the tracheal tube. The tracheostomy was eventually removed in 13 patients. Bronchoscopic evaluation of three patients at 4 months post-tracheostomy removal was normal and there has been no clinical evidence suggestive of tracheal stenosis in the remaining ten extubated patients. There was a 50% reduction in cost when compared to operative tracheostomy. Percutaneous tracheostomy is a simple, safe, cost-effective bedside procedure for critically ill ventilator-dependent patients. Endoscopic guidance appears to increase the safety of this procedure and may prevent complications of pneumothorax, subcutaneous emphysema, and paratracheal false passage previously reported with blinded percutaneous methods.

Adult↗
PubMed1989

The nonextractable tined endocardial pacemaker lead.

With the advent of the tined pacemaker electrode to improve endocardial fixation, increasing difficulty in extracting them when needed has resulted in reports of serious complications. The authors reviewed their experience between January 1975 and January 1985. During this 10 year period, 942 pacemakers were inserted and 73 were reoperated upon. In the reoperations, repositioning or removal of tined electrodes was attempted 28 times. Repositioning or removal was not possible in 12 of the 28 cases (43%). In 22 of 28, the attempts to remove tined leads were carried out more than one month after the original implantations and in this group the failure rate was 54.5% (12 of 22). All attempts of removal within one month of implantation were successful (six of six). No leads were retained during the period between January 1984 and January 1985. All 12 retained leads were followed-up for five years, five of which were retained in the presence of pacemaker pocket infections. After removal of the power pack and lead distal to the cephalic or subclavian vein inlet, control of infection was achieved in all five cases. One patient was noted to have the retained lead migrate into the right pulmonary artery but was asymptomatic at 35 months after catheter migration was detected. Until now, no thoracotomy for lead extraction has been required in this series.(ABSTRACT TRUNCATED AT 250 WORDS)

Electrodes, Implanted↗
PubMed1989

Mucociliary function in autotransplanted, allotransplanted, and sleeve resected lungs.

Tracheobronchial mucociliary function in dogs that underwent left upper sleeve lobectomy was compared with that of dogs that underwent left lung autotransplantation or allotransplantation (n = 5 each). Proximal airway clearance was measured by observing the movement of carbon particles through a bronchoscope. Preoperative and postoperative clearance rates for the right lungs in these dogs were unchanged. Although preoperative clearance rates in the transplanted left lungs were comparable with those of the right lungs, these left lungs were unable to clear the carbon particles during a 15-minute observation period 3 weeks postoperatively. In contrast, preoperative and postoperative clearance rates for the dogs that underwent sleeve resection were unchanged for both lungs. Mucus rigidity was studied by microrheometry and was found to be significantly increased postoperatively for samples collected from the autotransplanted and allotransplanted lungs than for samples collected from the untreated right lungs. These changes in mucus were noted for forces representing both normal ciliary beat and coughing. Viscoelastic properties of mucus were not significantly altered after sleeve lobectomy. Microscopic study showed squamous cell metaplasia and relative disappearance of bronchial glands distal to the anastomosis in all transplanted lungs. These changes were less pronounced in the sleeve resected bronchi. We conclude that changes in rheologic characteristics of mucus can impair mucociliary clearance and may be related to denervation after lung transplantation. Bronchial devascularization may have an additional effect of altering mucosal structures and function in the early postoperative period after lung transplantation. These effects are avoided by preserving peribronchial tissue in sleeve resection.

Animals↗
PubMed1986

Gastric carcinoma: intestinal metaplasia and tumor growth patterns as indicators of prognosis.

We have reviewed 200 cases of gastric carcinoma treated between 1970 and 1980 to assess the value of intestinal metaplasia in the stomach and tumor growth patterns in determining prognosis. Intestinal metaplasia was found to be more frequently associated with early gastric tumors, expanding-type tumors, and tumors located in the antrum. The survival rate was 53% with intestinal metaplasia and 34% without. Sixty-three percent of expanding tumors with metaplasia survived. If the lymph nodes were not involved, the survival rate with metaplasia was 81%. We conclude that intestinal metaplasia and growth patterns are valuable in predicting outcome. Preoperative evaluation of gastric tumors should include multiple endoscopic mucosal biopsy specimens. If intestinal metaplasia is present, the improved possibility of survival should influence the surgeon in the choice of operative treatment.

Female↗
PubMed1984

The effects of pulmonary atelectasis and reexpansion on lung cellular immune defenses.

Pulmonary atelectasis predisposes the lung to infection. This condition may be partly due to impaired cellular immune response of the collapsed lung segment. We postulated that atelectasis may affect alveolar macrophage (AM) antibacterial function. To test this hypothesis, atelectasis was induced in the right upper lobes of piglet lungs. Alveolar macrophages harvested by bronchoalveolar lavage of collapsed segments for up to 24 hours showed progressive depression of their phagocytic activity against Pseudomonas aeruginosa in vitro. However, their intracellular bactericidal activity did not change. Reexpansion of the atelectatic lobes with mechanical ventilation and 100% oxygen supplementation for four hours after six hours of atelectasis resulted in reversal of the impaired AM phagocytic activity. These observations presented insight into the mechanisms of susceptibility to lung infection in pulmonary atelectasis and the potential for its reversal.

Animals↗
PubMed1984

Pulmonary bacterial clearance and alveolar macrophage function in septic shock lung.

The association between the pulmonary bacterial clearance and the development of septic shock lung has been demonstrated in porcine and canine experimental models. In order to elucidate the role of the pulmonary reticuloendothelial system in bacterial clearance, the functions of alveolar macrophages (AM) obtained by bronchopulmonary lavage were studied. Five piglets were infused intravenously with Pseudomonas aeruginosa labeled with tritiated thymidine at 3 to 6 X 10(8) CFU/kg/min. Septic shock and manifestations like those of the adult respiratory distress syndrome developed within 1 h, and the pigs died within 2 to 3 h. Pulmonary bacterial clearance was 93% initially, and progressively decreased to 29%, as Pao2 decreased and lung water increased. The number of bacteria in the serial lung biopsy specimens increased steadily, although the distribution was not homogeneous. Differential centrifugations, repeated washings, and scintillation countings of the lavage fluid showed that in vivo AM phagocytosis was nil, despite the abundant bacteria found in the lavage fluid. However, when these AM were washed and tested in vitro in the presence of optimal concentrations of opsonin and oxygen, their phagocytic capability was well preserved, and was not significantly different from that of prebacterial infusion baseline values. It is concluded that in the septic shock lung, the lung clears bacteria not primarily by AM uptake but by other mechanisms, such as mechanical leakage into the pulmonary space, or by pulmonary intravascular leukocyte uptake. The apparent AM dysfunction in vivo is not intrinsic, and is likely to be caused by microenvironmental factors, such as lack of adequate opsonin and oxygen.

Animals↗
PubMed1984

Depression and delayed recovery of alveolar macrophage function during starvation and refeeding.

Malnourished patients are particularly vulnerable to pulmonary infection. In this study using a rat model, starvation was found to depress significantly the phagocytic capability of pulmonary alveolar macrophages which play important roles in the local cellular defenses of the lung. Intracellular bactericidal function of the alveolar macrophages was not affected. On refeeding, in spite of the rats regaining their body weights and the recuperation of certain systemic immune indexes, there was a delay in the recovery of alveolar macrophage phagocytic function.

Animals↗
PubMed1983

The effects of splenectomy and splenic implantation on alveolar macrophage function.

The effect of splenectomy on the ability of alveolar macrophages of young and adult rats to phagocytize Pneumococci, Types 3 and 14, and Pseudomonas aeruginosa was studied. Young animals showed a significant (15%) decrease in the phagocytosis of pneumococci type 14, 4 weeks after splenectomy. This depression increased to 30% in 6 weeks' time. Such depression was also noted when young splenectomized rat alveolar macrophages were challenged with Pseudomonas aeruginosa but not with type 3 pneumococci 6 weeks postsplenectomy. Three months following splenectomy in young animals, the rats were grown and they seemed to regain their normal phagocytic activity against pneumococci type 14. Adult rats also showed no alteration in their phagocytic activity against type 3 pneumococci. Autoimplantation of the spleen had a protective effect on the phagocytosis of type 14 pneumococci, and a nonsignificant effect on that of type 3. The present study postulates a modulatory role of the spleen on alveolar macrophage function. Splenectomy may cause the impairment of local lower respiratory immune function, making lungs vulnerable to specific bacterial invasion. Such splenic modulatory effect on alveolar macrophage phagocytic function seems to be age and antigen specific.

Aging↗
PubMedDate not supplied

Size matching in lung transplantation.

Volume concordance between donor lungs and the chest cavities of transplant recipients has important perioperative and postoperative implications. Between December 1987 and August 1991, 90 patients underwent lung transplantation in the Joint Marseilles-Montreal Lung Transplantation Program: 51 patients had double lung transplants, 19 patients had single lung transplants, and 20 patients had heart-lung transplants. There were 18 children (age range, 7 to 17 years) and 72 adults (age range, 18 to 58 years). Size matching was based on measurement of the submammary thoracic perimeter. Patient age (+/- 2 years) was also taken into consideration in children. Airway anastomoses were bronchial except for all heart-lung transplant patients and two double lung transplant patients, who had tracheal anastomoses. Occasional differences between donor and receiver bronchial diameters in children (greater donor size twice and smaller donor size once) required bronchoplasty in three instances. Healing was normal in these three instances, and no bronchial stenoses were noted. Performance of separate sutures rather than continuous running sutures on the cartilaginous anterior portion facilitated correction of airway diameter inequalities in adults. Excess volume was noted in three patients during closure of the thorax. In one patient, donor and recipient thoracic perimeters were similar. In two patients, however, donor size was greater by more than 20%. This was corrected by pneumoreduction with a surgical stapler. Lung size was decreased by 10% to 40% with use of this technique. Thoracic closure was facilitated and hemodynamic instability was thus corrected. No functional abnormalities were noted after surgery once the differences in lung size were corrected.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

Successful transplantation of a lung allograft from a carbon monoxide-poisoning victim.

Donor availability remains the limiting factor to heart and lung transplantation. Donor selection criteria need to be continuously reassessed to expand the donor pool. The feasibility of organ donation from victims of carbon monoxide poisoning is unclear. We present a case of successful single lung transplantation from a carbon monoxide-poisoning victim.

Adult↗
PubMedDate not supplied

Improved outcome of rat lung transplantation with modification of the nonsuture external cuff technique.

BACKGROUND: The development of lung transplantation in inbred rats has simplified immunologic studies concerning lung allografts. Unfortunately, up to now, such models have been limited by the high level of surgical expertise required. METHODS: In this study 92 rats underwent left lung transplantation with a simplified cuff technique. The feasibility and reliability of this technique was determined by examining graft patency through the use of gross and histologic examination, angiography, and bronchography. RESULTS: On gross examination, grafts looked well perfused and ventilated. Histologic examination showed little evidence of foreign body reaction against the Teflon cuff devices, and angiography showed no abnormalities; however, bronchography did show signs of airway stricture at the site of the anastomosis. CONCLUSION: We conclude that the nonsuture external cuff technique with Teflon devices represents a reliable, safe, and fast method for performing orthotopic left lung transplantation in the rat.

Anastomosis, Surgical↗
PubMedDate not supplied

Slow-rate, high-pressure ventilation: a method of management of difficult transplant recipients during sequential double lung transplantation for cystic fibrosis.

Single and double lung ventilation can be extremely difficult in patients with cystic fibrosis who require sequential double lung transplantation. This article reports the successful use of slow-rate, high-pressure ventilation in the management of two ventilator-dependent patients who would otherwise have needed to be supported by cardiopulmonary bypass.

Adolescent↗