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Biomedical subjects

Ahmed A Arifi

Publications and source records attributed to Ahmed A Arifi.

At least 19 recordsLinked to original sources

Differential, time-dependent effects of perivenous application of fibrin glue on medial thickening in porcine saphenous vein grafts.

OBJECTIVE: Neointimal and medial thickening play a critical role in late vein graft failure following CABG. Previous ex vivo experiment suggested that perivenous application of fibrin glue may reduce the damage in the circular smooth muscle cell layer of the media of the vein graft shortly after exposing to arterial pressure. However, the in vivo as well as the longer term impact of this intervention remain unknown. METHODS: Bilateral saphenous vein-carotid artery interposition grafting was performed in eight large white pigs (35-45 kg). In each pig, one of the grafts was randomly selected to receive perivenous fibrin glue support while the contralateral graft served as control. At 1 and 4 months following surgery (n=4 pigs in each group), all 16 patent vein grafts were removed and pressure-fixed. Multiple histological sections from each graft were prepared. Proliferating cell nuclear antigen (PCNA) was detected by immunocytochemistry. Vein graft morphology was assessed using computer-aided planimetry. RESULTS: Although perivenous application of fibrin glue had little effects either on medial thickness 1 month after implantation or on PCNA index, it significantly increased medial thickness (control: 0.37+/-0.02 mm; treated: 0.55+/-0.02 mm, p<0.001) and total wall thickness (control: 0.75+/-0.04 mm; treated: 0.92+/-0.04 mm, p=0.008) at 4 months (mean+/-SEM; n=4 in each group). CONCLUSIONS: Our data indicated that perivenous application of fibrin glue enhances graft thickening and as such does not constitute a strategy for preventing late vein graft failure after CABG.

Anastomosis, Surgical↗

Inflammatory response to pulmonary ischemia-reperfusion injury.

Lung ischemia-reperfusion (IR) injury is one of the most important complications following lung transplant and cardiopulmonary bypass. The pulmonary dysfunction following lung IR has been well documented. Recent studies have shown that ischemia and reperfusion of the lung may each play significant yet differing roles in inducing lung injury. The mechanisms of injury involving neutrophil activation, and the release of numerous inflammatory mediators and oxygen radicals also contributes to lung cellular injury, pneumocyte necrosis, and apoptosis. We herein review the current understanding of the underlying mechanism involved in lung IR injury. The biomolecular mechanisms and interactions which lead to the inflammatory response, pneumocyte necrosis, and apoptosis following lung IR therefore warrant further investigation.

Humans↗

Invited commentary.

Explore the source record for details and available documents.

Cardiopulmonary Bypass↗

Post-pneumonectomy empyema: current management strategies.

Post-pneumonectomy empyema is an uncommon but potentially life-threatening complication. It has a strong association with bronchopleural fistula, which acts as a continued source of infection into the thoracic cavity. Numerous risk factors have been identified and strategies formulated to minimize its occurrence. When bronchopleural fistula occurs, its treatment depends on several factors including extent of dehiscence, degree of pleural contamination and general condition of the patient. Early diagnosis and assessment with appropriate investigations, and aggressive therapeutic strategies are paramount in controlling sepsis, facilitating closure of fistula, and sterilization of the closed pleural space. Recent success with repeat debridement has made routine space obliteration not mandatory in management. The development of minimal-access interventions including video-assisted thoracic surgery, endoscopic application of tissue glue and stenting may be additional tools to complement conventional surgery in post-pneumonectomy empyema management.

Bronchial Fistula↗

The potential use of type-5 phosphodiesterase inhibitors in coronary artery bypass graft surgery.

Exaggerated vasospasm, platelet activation, and early graft occlusion are significant barriers to successful coronary artery bypass grafting (CABG). Interestingly, vascular smooth muscle and platelets are predominant sources of type-5 phosphodiesterase (PDE5) in the body, and this enzyme is specifically inhibited by PDE5 inhibitors (eg, sildenafil citrate). Together with endogenous nitric oxide, sildenafil can induce pulmonary and coronary vasodilation, precondition the myocardium, reduce platelet activation, and potentially reduce early graft occlusion. Currently, there are no published clinical trials investigating sildenafil in coronary surgery. Recent studies on the potential use of sildenafil strongly support its beneficial effects in a wide range of patients with cardiovascular diseases. Therefore, we sought to review the literature, explore the current hypothesis that the use of sildenafil in coronary surgery patients can be beneficial, and attempt to define its potential place in the setting of CABG.

3',5'-Cyclic-GMP Phosphodiesterases↗

Rupture of a giant coronary artery aneurysm due to Kawasaki disease.

Coronary artery aneurysm requiring surgery is rare. We report a case of a ruptured giant coronary artery aneurysm due to Kawasaki vasculitis which presented with cardiac arrest and was successfully treated by emergency coronary artery bypass grafting. The controversies surrounding the management of this disease are also discussed.

Anticoagulants↗

Video-assisted thoracic surgery for primary spontaneous hemopneumothorax.

OBJECTIVE: Video-assisted thoracic surgery (VATS) has changed the way we manage a number of thoracic conditions. This study presents near over a decade of experience from our institution on management of spontaneous hemopneumothorax (SHP), with particular reference to the use of VATS. METHODS: Retrospective review between March 1988 and December 2002 with 793 patients treated for spontaneous pneumothorax, 30 (3.8%) patients had SHP. The clinical features, indications for surgery and outcomes are discussed. RESULTS: All 30 SHP patients were male with mean age of 25 years. Signs of significant hypovolemia occurred in 4 patients, 3 required blood transfusion. Mean initial blood drainage from tube thoracostomy was 594 ml. All SHP patients received surgery (5 thoracotomies, 25 VATS). Active bleeding was identified in 16 patients; 12 from torn apical vascular adhesion band and 4 from vascular bleb. Postoperative complications after thoracotomy include 2 chest infections and 1 air leak, while VATS had 1 chest infection and 1 air leak (P=0.022). Mean postoperative hospital stay following VATS was 3.9 days and thoracotomy 7.5 days (P=0.0021). There is no recurrence of pneumothorax or SHP during mean follow-up of 21 months. CONCLUSION: SHP can be life threatening and is a cause for patients presenting with unexplained signs of significant hypovolemia. Surgery in the form of VATS should be considered early in the management of SHP, with potentially less postoperative complications and shorter postoperative hospital stay compared with open thoracotomy.

Adolescent↗

Early results of endoscopic lung volume reduction for emphysema.

BACKGROUND: We determined the feasibility, safety, and short-term efficacy of bronchoscopic placement of a one-way endobronchial valve in selected bronchopulmonary segments as an alternative to surgical lung volume reduction. METHODS: A total of 21 patients with incapacitating emphysema who underwent this procedure were studied. All patients had placement of the endobronchial valves into the most emphysematous lung segments. We recorded any major complications or deaths attributed to the procedure and analyzed (1) improvements in the spirometric and functional parameters and quality of life and (2) the radiologic changes compared with the baseline data at 30 and 90 days. RESULTS: A total of 20 patients had complete follow-up data. There was no mortality in the group studied. The forced expiratory volume at 1 second, forced expiratory volume at 1 second (percentage of predicted), forced vital capacity, and forced vital capacity (percentage of predicted) all improved significantly at 90 days (0.73 +/- 0.26 L vs 0.92 +/- 0.34 L [P =.009]; 33.3% +/- 11.9% vs 42.2% +/- 15.0% [P =.006]; 1.94 +/- 0.62 L vs 2.25 +/- 0.61 L [P =.015]; and 63.3% +/- 17.6% vs 73.9% +/- 17.1% [P =.012], respectively). The 6-minute walking distance improved at 30 and 90 days (251.6 +/- 100.2 m vs 306.3 +/- 112.3 m and 322.3 +/- 129.7 m; P =.012 and P =.003). The results of the 36-Item Short-Form Health Survey and the St George Respiratory Questionnaire showed significant improvements at 90 days. The Medical Research Council dyspnea grade also improved significantly at 30 and at 90 days (P =.006 and P =.003, respectively). CONCLUSIONS: Endobronchial valve placement is a safe procedure, with significant short-term improvements in functional status, quality of life, and relief of dyspnea in selected patients with emphysema. A larger study with long-term follow-up is therefore warranted.

Adult↗

Beating heart revascularization with or without cardiopulmonary bypass: evaluation of inflammatory response in a prospective randomized study.

OBJECTIVE: On-pump beating heart coronary artery surgery provides the opportunity to examine the isolated effect of cardiopulmonary bypass. This prospective randomized study compares the early clinical outcomes and inflammatory response of patients undergoing elective on-pump and off-pump beating heart coronary artery bypass grafting. METHOD AND PATIENTS: Thirty-seven consecutive patients undergoing elective coronary artery bypass grafting were recruited from a pool of 73 patients, with 19 patients randomized to on-pump beating heart surgery and 18 patients to off-pump coronary bypass surgery. Intraoperative events and postoperative outcomes were recorded. Plasma levels of interleukin-6, interleukin-8, and interleukin-10, tumor necrosis factor-alpha, and vascular cell adhesion molecule-1 were measured before the operation, intraoperatively, after the operation, and 4, 24, and 48 hours thereafter. RESULTS: There was no significant difference in clinical outcomes between the 2 groups. The operating time was longer and consumption of platelets was greater for the on-pump beating heart group. There was no postoperative mortality or major complication in either group. There was significant elevation in the levels of interleukin-6, interleukin-8, and interleukin-10 and tumor necrosis factor-alpha during and immediately after the operations in the on-pump beating heart group when compared with the off-pump group. Levels of interleukin-8 (P =.01) and tumor necrosis factor-alpha (P =.0004) remained significantly elevated 4 hours after the operation in the on-pump beating heart group. The level of vascular adhesion molecule dropped significantly during the operation but was elevated 4 hours (P =.026) after the operation in the on-pump beating heart group. CONCLUSION: The use of cardiopulmonary bypass alone without global myocardial ischemia secondary to aortic crossclamping and cardioplegic cardiac arrest can trigger intense inflammatory responses.

Aged↗

Intravenous leiomyomatosis: two cases with different routes of tumor extension.

Intravenous leiomyomatosis is a rare smooth muscle tumor. We report two cases of intravenous leiomyomatosis that grew along different routes of the venous system into the inferior vena cava and the right atrium. The different route of extension makes a difference in the ease of excision of tumor masses. Using MEDLINE together with the references in each publication, we identified all cases of intracardiac leiomyomatosis reported in the English literature in the period between 1980 and 2003 and performed a brief review on this potentially lethal disease entity.

Adult↗

The impact of thoracic surgical access on early shoulder function: video-assisted thoracic surgery versus posterolateral thoracotomy.

OBJECTIVE: Whether video-assisted thoracic surgery (VATS) is associated with less shoulder dysfunction when compared with posterolateral thoracotomy (PLT) remains unclear. We therefore conducted this prospective study to assess the shoulder function in patients following major lung resection using either the VATS or PLT approach. METHODS: Twenty-nine consecutive patients were prospectively recruited into the study. Eighteen patients underwent major lung resection through VATS (VATS group) and 11 patients through PLT (open group). Shoulder function was measured preoperatively, and postoperatively at 1 week, 1 month and at 3 months. All assessments were done by two experienced physiotherapists using the American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form. RESULTS: Shoulder strength was significantly better preserved in the VATS group at 1 week after surgery when compared with the PLT group (92 versus 81% of preoperative value; P=0.024). VATS patients also had better range of motion especially with respect to external rotation at 1 week (98 versus 91%; P=0.015) and forward elevation at 1 month (98 versus 93%; P=0.024) and 3 months after surgery (100 versus 96%; P=0.021). Analgesic requirement was significantly less in the VATS group postoperatively at 1 week (P=0.009) and 1 month (P=0.004). CONCLUSIONS: VATS major lung resection is associated with significantly less shoulder dysfunction and pain medication requirement in the early postoperative period when compared to the PLT approach.

Activities of Daily Living↗

Tumor p16M is a possible marker of advanced stage in non-small cell lung cancer.

BACKGROUND AND OBJECTIVES: The inactivation of the tumor suppressor gene p16 by methylation (p16M) has been recognized recently as an important process in the oncogenesis for a variety of carcinomas. There have been few reports of its use in lung cancer. We investigate p16M in patients with non-small cell lung cancer (NSCLC). METHODS: p16M in tumor, plasma, and pleural lavage fluid from patients with resectable NSCLC were investigated by using methylation-specific polymerase chain reaction. RESULTS: Of the 33 patients studied, 14 (42%) had p16M tumors. There was a significant association between p16M tumors and advanced TNM staging (stage III or IV, P=0.047, Fisher exact test). Circulating p16M was identified in 2 of the 14 patients with p16M tumor and was also associated with advanced TNM staging (P=0.049). The presence of plasma p16M in NSCLC patients and in p16M tumor patients was associated with poor survival and shorter disease-free survival (P=0.0028, P=0.0039, Kaplan-Meier log rank). In addition, p16M was present in three preresectional and four postresectional lavage samples. Preresectional p16M was associated with poor survival and shorter disease-free survival (P=0.0085). p16M tumor involving the visceral pleura was significantly associated with positive p16M postresectional lavage. CONCLUSIONS: Positive tumor and plasma p16M indicate advanced staging in NSCLC. Patients with plasma and preresection pleural lavage p16M have shorter survival. Further research in this direction is warranted.

Adult↗