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Biomedical subjects

I Bahadir

Publications and source records attributed to I Bahadir.

11 recordsLinked to original sources
PubMed1992

Angioscopy in endovascular surgery: recent technical advances to enhance intervention selection and failure analysis.

Recent technical and procedural modifications have greatly enhanced the usefulness of angioscopy during angioplasty. A pulsed irrigation system, proximal and distal blood flow control by pressure, and attention to sheath/vessel diameter ratio were incorporated into a study in which angioscopy was used for pretreatment assessment in 23 patients with symptomatic peripheral vascular disease presenting for initial (8 patients) evaluation or repeat treatment (15 patients) following a previous vascular procedure. Twenty-five lesions were examined with a 2.3 mm flexible angioscope equipped with an irrigating lumen; there were no complications attributable to angioscopy. The angioscope was useful in the characterization of lesions for selection of the recanalization technique. Lesions more amenable to initial atherectomy were visualized in 12 patients; 7 occlusions were successfully treated with laser/balloon angioplasty, with angioscopy assisting in probe and/or wire passage in 4 cases. Three late reocclusions were identified angioscopically as due solely to thrombosis, indicating the need for thrombolytic therapy. Angioscopy also identified 4 cases of incomplete recanalization despite a satisfactory arteriographic image. Angioscopy was also used to evaluate stenotic lesions unaccompanied by thrombus formation in patients previously treated with laser-assisted angioplasty. Histologic evaluation of the biopsied plaques identified intimal hyperplasia as the etiology, matching identically similar specimens harvested from a lesion treated with balloon dilation only.

Aged↗
PubMed1991

Laser-assisted angioplasty in the treatment of prosthetic graft stenosis.

Late failure of peripheral bypass grafts has been treated primarily by secondary reconstruction. Laser-assisted angioplasty is an optional therapy that the authors investigated in 28 prosthetic grafts over a two-year period. Twenty-five symptomatic patients with 28 peripheral prosthetic arterial bypass grafts (25 polytetrafluoroethylene [PTFE] grafts and 1 each of knitted Dacron, Teflon, and umbilical vein) demonstrated graft occlusion (25) or high-grade stenoses (3). All patients underwent standard laser-assisted angioplasty using a continuous wave Nd:YAG laser source and hybrid probe. Twenty-one grafts (75%) were successfully recanalized with adequate restoration of flow through the conduit. All 7 failures were in occluded PTFE grafts that presented with either recalcitrant lesions (5) or perforations (2) at the distal anastomoses. There have been 3 long-term failures (14%) to date in the successfully treated group, all in PTFE grafts. Two patients suffered recurrent thrombosis and 1 developed an inexplicable graft infection five months after laser treatment. Laser-assisted angioplasty appears to be a clinically viable alternative treatment for prosthetic graft stenosis and recanalization of grafts occluded at their distal anastomosis.

Aged↗
PubMed1990

Intraoperative coronary excimer laser angioplasty: preliminary clinical experience.

Diffuse coronary artery atherosclerosis is generally recognized as a deterrent to successful revascularization if it cannot be adequately treated. Mechanical endarterectomy can be useful, but it is not the optimal solution owing to the associated higher incidences of perioperative infarction and mortality. The use of laser energy as an endarterectomy tool appears promising. To investigate the application of excimer laser radiation to intraoperative coronary artery endarterectomy, 15 stenotic lesions in 13 patients were treated with excimer irradiation during coronary artery bypass grafting. Eleven (73%) of the lesions were enlarged by the excimer probe (6 of the successes were in calcified lesions). The 4 arteries not enlarged by the excimer laser all demonstrated calcified lesions. There were 3 perforations and 2 dissections, all but 1 in heavily calcified arteries. The results of this phase 1 safety and efficacy study indicate that excimer irradiation can recanalize most arteries, including total and subtotal occlusions and some calcified lesions. Further evaluation with better delivery systems is needed to determine whether the perforation rate can be reduced.

Aged↗
PubMed1989

Applications and limitations of laser-assisted angioplasty.

Laser-assisted angioplasty is rapidly evolving into a promising adjunct to or replacement for standard vascular procedures. A protocol was devised to evaluate the technique in a non-selected, consecutive patient population to define the applications and limitations of the technique. In a 12-month period, 358 lower-limb atherosclerotic lesions were treated with laser/balloon angioplasty [percutaneously (52%) or open (48%)] in 206 consecutive patients. Overall, the laser/balloon technique recanalised 234 lesions (65% laser success), judged clinically effective by a greater than 0.15 improvement in the ankle/brachial index and elimination of symptoms. Operative complications included: perforation (15, 4.2%); thrombosis (16, 4.5%); spasm (5, 1.4%); and false aneurysm at the puncture site (7, 2.0%). Of the 124 failures (35%) categorised for analysis, the most common cause was inability to cross the lesion in 20 cases. This experience has identified three significant clinical limitations to successful laser recanalisation: calcification, inadequate distal circulation, and inability to control restenosis/reocclusion (collapsible lesions and accelerated plaque deposition). Further research is needed to determine if thermal injury seriously compromises the safety and long-term outcome of laser-assisted angioplasty.

Adult↗
PubMed1987

Postoperative complications necessitating right lower lobectomy in a heart-lung transplant recipient with previous sternotomy.

Heart-lung transplantation for treatment of end-stage cardiopulmonary disease continues to be plagued by many problems. Three primary ones are the technical difficulties that can be encountered, particularly in those patients who have undergone previous cardiac operations, the additional restriction on donor availability imposed by the lack of satisfactory preservation techniques, and the need for lung size compatibility. Two of these difficulties and others surfaced postoperatively in a heart-lung transplant recipient who presented a series of unique operative and therapeutic challenges. A 42-year-old woman with chronic pulmonary hypertension and previous atrial septal defect repair underwent a heart-lung transplantation in August 1985. The operative procedure was expectedly complicated by bleeding from extensive mediastinal adhesions from the previous sternotomy and bronchial collateralization. Excessive chest tube drainage postoperatively necessitated reoperation to control bleeding from a right bronchial artery tributary. Phrenic nerve paresis, hepatomegaly, and marked abdominal distention caused persistent atelectasis and eventual right lower lobe collapse. Arteriovenous shunting and low oxygen saturation necessitated right lower lobectomy 15 days after transplantation, believed to be the first use of this procedure in a heart-lung graft recipient. Although oxygenation improved dramatically, continued ventilatory support led to tracheostomy. An intensive, psychologically oriented physical therapy program was initiated to access and retrain intercostal and accessory muscles. The tracheostomy cannula was removed after 43 days and gradual weaning from supplemental oxygen was accomplished. During this protracted recovery period, an episode of rejection was also encountered and successfully managed with steroid therapy. The patient continued to progress satisfactorily and was discharged 83 days after transplantation. She is well and active 20 months after discharge.

Adult↗
PubMed1977

Soft tissue necrosis and gangrene complicating treatment with the coumarin derivatives.

Skin and soft tissue necrosis, in association with the coumarin derivatives, characteristically afflicts females between the third and tenth days of treatment. Anatomic regions abundant in subcutaneous fat are most commonly affected. Many of these patients have underlying serious medical problems. Three additional patients with tissue infarction complicating coumadin therapy are presented. Possible etiologic mechanisms are discussed, but the basic physiopathologic condition remains an enigma. Venous thrombosis can be a related clinical phenomenon. Treatment perspectives are outlined.

Adult↗