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Abul Hasan Muhammad Bashar

Publications and source records attributed to Abul Hasan Muhammad Bashar.

18 recordsLinked to original sources
PubMed2006

Right aortic arch with aberrant left subclavian artery symptomatic in adulthood.

Congenital malformations of the aortic arch are rarely found in adulthood. We describe three cases of right aortic arch with aberrant left subclavian artery with left-sided ligamentum arteriosum presenting in adulthood as vascular rings with symptoms of tracheal compression. Varying presentation as well as surgical strategy which was individualized according to the pathological anatomy of each case are discussed.

Adult↗
PubMed2006

Aorto-right atrial fistula following acute type A aortic dissection repair.

This report describes a rare case of aorto-right atrial fistula caused by rupture of a huge pseudoaneurysm that developed at the proximal aortic anastomotic site after total aortic arch replacement for acute type A aortic dissection. Preoperative aortography revealed that the fistula communicated with the right heart, but it was intraoperative Doppler transesophageal echocardiography that confirmed its course into the right atrium. Repeat total aortic arch replacement with concomitant direct closure of the fistula was performed successfully. The underlying cause of the pseudoaneurysm was the dehiscence of sutures at the proximal aortic anastomotic site, probably due to gelatin-resorcin-formaldehyde glue.

Acute Disease↗
PubMed2006

Intrathecal injection of bone marrow stromal cells attenuates neurologic injury after spinal cord ischemia.

BACKGROUND: It has been shown that transplantation of bone marrow stromal cells (MSCs) into the ischemic brain improves functional outcome. We sought to investigate whether intrathecal injection of MSCs can attenuate neurologic injury of spinal cord ischemia. METHODS: Rabbit MSCs were expanded in vitro and were pre-labeled with bromodeoxyuridine. Spinal cord ischemia was induced in rabbits by infrarenal aortic occlusion. Group A and control A were subjected to a 20-minute ischemia and the ischemic duration was extended to 30 minutes in group B and control B. Two days before spinal cord ischemia, 1 x 10(8) MSCs were intrathecally injected into groups A and B, whereas vehicle alone was injected into the control groups. Hind-limb motor function was assessed during a 14-day recovery period with Tarlov criteria, and then histologic examination was performed. RESULTS: Marrow stromal cells survived and engrafted into the spinal cord 2 days after transplantation, and more MSCs were found in the lumbar spinal cord (ischemic segment) than in the thoracic spinal cord (nonischemic segment) at 14 days. Compared with their respective control groups, Tarlov scores were significantly higher in both groups A and B (p < 0.05, group A vs control A, at 2, 7, and 14 days; p < 0.05, group B vs control B, at 1, 2, 7, and 14 days, respectively). The number of intact motor neurons was much higher in the two experimental groups (p < 0.01 vs the corresponding control groups, respectively). CONCLUSIONS: Intrathecal injection of MSCs attenuates ischemic injury of spinal cord.

Animals↗
PubMed2006

Total aortic arch replacement in patients with arch vessel anomalies.

BACKGROUND: The presence of anomalous arch vessels has considerable impact on aortic arch reconstruction techniques and cerebral protection methods when the separated graft technique is adopted to perform total arch replacement. We analyzed our experience of total arch replacement in patients with arch vessel anomalies. METHODS: Among the 220 patients undergoing total arch replacement at our institution, 21 patients (9.5%) had various arch vessel anomalies. Common brachiocephalic trunk was found in 8 patients (3.6%); an isolated left vertebral artery in 9 (4.1%); aberrant right subclavian artery in 3 (1.4%); and coexistent common brachiocephalic trunk and isolated left vertebral artery in 1 (0.5%). In 4 of the 9 patients with isolated left vertebral artery, preoperative diagnosis was possible with magnetic resonance angiography or three-dimensional computed tomography. In cases with common brachiocephalic trunk, total arch replacement could be performed with the usual techniques after separating the innominate and left common carotid arteries from each other. The isolated left vertebral artery was anastomosed to the left subclavian artery graft in 7 patients and to the native left subclavian artery in 2. In the aberrant right subclavian artery variety, a distal aortic anastomosis was performed distal to the orifice of this anomalous artery. The aberrant vessel was reconstructed on the right side of the trachea and esophagus. RESULTS: There was no early or in-hospital mortality. No neurologic complication attributable to the arch vessel anomalies was found. CONCLUSIONS: A precise preoperative diagnosis is very important for the selection of an appropriate surgical strategy in patients with arch vessel anomalies. Magnetic resonance angiography and three-dimensional computed tomography may be useful diagnostic tools in these patients.

Aged↗
PubMed2006

Nonviral gene transfer of hepatocyte growth factor attenuates neurologic injury after spinal cord ischemia in rabbits.

OBJECTIVE: Paraplegia caused by spinal cord ischemia remains a serious complication after surgical repair of thoracoabdminal aortic aneurysms. Hepatocyte growth factor is a potent angiogenic and neurotrophic factor. We sought to investigate the neuroprotective effect of gene transfer of hepatocyte growth factor on spinal cord ischemia in rabbits. METHODS: Human hepatocyte growth factor expression plasmid was combined with hemagglutinating virus of Japan envelope vector. Hemagglutinating virus of Japan envelope vector containing the hepatocyte growth factor gene was injected intrathecally into the experimental rabbits, whereas control vector or saline was given to the control animals. Five days later, spinal cord ischemia was induced by means of infrarenal aortic occlusion for 30 minutes. Hind-limb motor function was assessed during a 14-day recovery period with Tarlov criteria. RESULTS: Human hepatocyte growth factor was detected in the cerebrospinal fluid 3 days after gene transfer, and the level peaked on day 5. Compared with the control animals, hepatocyte growth factor gene transfer significantly increased the capillary density in the gray matter and decreased the spinal cord edema. All rabbits pretreated with saline or control vector had hind-limb paraplegia (Tarlov score = 0) 14 days after spinal cord ischemia. However, previous transfection of the hepatocyte growth factor gene remarkably enhanced the Tarlov scores, and 8 of the 9 rabbits showed normal motor function (Tarlov score = 5) after a 14-day recovery period. Histologic examination showed that the intact motor neurons were preserved to a much greater extent in the rabbits transfected with the hepatocyte growth factor gene. CONCLUSION: Gene transfer of hepatocyte growth factor attenuates neurologic injury after spinal cord ischemia.

Animals↗
PubMed2005

Experimental study on the protective effects of edaravone against ischemic spinal cord injury.

OBJECTIVE: Reactive free radical species are thought to be involved in ischemic spinal cord injury. We investigated the effects of edaravone (Mitsubishi Pharma Co, Tokyo, Japan), a free radical scavenger, on spinal ischemia-reperfusion injury in a rabbit model. We also sought to estimate free radicals in the spinal cord using the microdialysis method. METHODS: Spinal cord ischemia was induced in New Zealand White rabbits. The animals were then divided into 4 groups. In the first experiment, which was carried out in group A (non-edaravone treated) and group B (edaravone treated), we assessed neurologic function and evaluated spinal cord histopathology. In the second experiment, which was performed in group C (non-edaravone treated) and group D (edaravone treated), we sequentially estimated the level of free radical species in the spinal cord with the microdialysis method. RESULTS: In the first experiment group B showed better neurologic function than group A. The number of viable neurons in the spinal cord gray matter was also higher in group B than in group A. The second experiment revealed that the level of free radical species was lower in group D at 75, 90, and 150 minutes after the beginning of reperfusion compared with levels seen in group C. The appearance of free radical species in the latter group was found to have a biphasic pattern, with peaks at 75 and 150 minutes after the beginning of reperfusion. CONCLUSION: Edaravone exerted a significant protective effect on the spinal cord against ischemia-reperfusion injury by suppressing the level of free radical species, which was demonstrated with the microdialysis method.

Animals↗
PubMed2003

Mechanical properties of various z-stent designs: an endovascular stent-grafting perspective.

PURPOSE: To comparatively assess the mechani-cal behavior of various clinically relevant Z-stent designs. METHODS: A total of 16 Z-stents of original, biliary, spiral, and double-skirted designs (n=4 for each) were constructed using similar specifications for all. Stents were then evaluated for stiffness, snap opening force (SOF), flexibility, and displacement force using a novel tensiometer. Differences among the stents were determined using statistical methods. Stents explanted from dog aorta after a mean follow-up of 13 months were examined under a scanning electron microscope for surface defects. RESULTS: Forces required for about 50% reduction in diameter were 1.88 +/- 0.16 N, 3.81 +/- 0.21 N, 2.76 +/- 0.22 N, and 3.35 +/- 0.19 N for original, biliary, spiral, and skirted designs, respectively. Differences among the four designs were statistically significant at almost all points of measurement (P < 0.0001). Biliary and skirted designs showed higher SOF values in the early measurements. Stents explanted from dog aorta after a mean duration of 13 months showed no obvious corrosion or breakage in the wire struts. CONCLUSIONS: Significant differences exist among the various Z-stent designs in terms of their mechanical properties. Understanding them should help to select the appropriate stent for a given lesion. 316L stainless steel shows a favorable long-term tissue interaction.

Angioplasty↗
PubMed2002

Total aortic arch replacement for thoracic aneurysm involving an isolated left vertebral artery.

We conducted 4 total aortic arch replacements in patients with an isolated left vertebral artery. In all 4, surgery was done using 4-branched arch grafts with moderately hypothermic selective cerebral perfusion and systemic circulatory arrest. All reconstructed isolated left vertebral arteries anastomosed to the native left subclavian artery or to the graft branch for this artery showed good patency. None of our patients had cerebral complications and all were discharged in good condition.

Aged↗
PubMed2002

Aortic root replacement using a homograft for recurrent valve endocarditis.

Prosthetic valve endocarditis is a relatively rare condition associated with high mortality. Endocarditis affecting 2 successive mechanical valves at the aortic position has not, to the best of our knowledge, been described. We reported such a patient whose condition was further complicated by mitral regurgitation, pulmonary hypertension, worsening heart failure, and cardiac conduction abnormalities. Considering the failure of 2 previous mechanical valves, we conducted a homograft replacement of the aortic root with coronary reattachment. Mitral regurgitation was treated by annuloplasty. The patient's early postoperative course was uneventful and he was doing well 16 months after surgery. We discuss the overall treatment strategy for recurrent prosthetic valve endocarditis and potential homograft advantages.

Adult↗
PubMed2002

Surgical outcome of acute type A aortic dissection: analysis of risk factors.

BACKGROUND: The aim of this study was to assess the risk factors for the early and late outcome of the surgical treatment of acute type A aortic dissection. METHODS: From 1983 to 2000, a total of 130 patients underwent operation for acute type A aortic dissection. Extent of distal aortic resection included ascending aorta in 19 patients (15%), hemiarch in 29 (22%), and total arch in 82 (63%). In all, 31 preoperative and perioperative variables were analyzed using univariate and multiple logistic regression models for independent predictors of in-hospital mortality and risk of late reoperation. After excluding in-hospital deaths, risk factors for late death were analyzed by Cox proportional hazard analysis. RESULTS: In-hospital mortality was 19.2% (25 of 130 patients). Multivariable analysis indicated that renal/mesenteric ischemia and shock were independent predictors of in-hospital death. At 10 years, the actuarial survival rate including in-hospital mortality was 70.9% +/- 4.7%, and the reoperation event-free rate was 73.5% +/- 5.7%. Aortic valve resuspension was an independent predictor of proximal aortic reoperation, whereas nonresection of intimal tear and younger age were independent predictors for distal aortic reoperation. Chronic obstructive pulmonary disease was the only independent predictor for late death. CONCLUSIONS: Patients' preoperative dissection-related complications and comorbidities significantly affect early and late survival rates after surgical treatment of acute type A aortic dissection.

Acute Disease↗
PubMed2002

Usefulness of antegrade selective cerebral perfusion during aortic arch operations.

BACKGROUND: To evaluate the safety and usefulness of antegrade selective cerebral perfusion (SCP) during arch aneurysm or aortic dissection operations. METHODS: Between January 1986 and December 2001, 330 patients underwent aortic arch repair using SCP. Operations were performed with the aid of hypothermic extracorporeal circulation, SCP, and systemic circulatory arrest in most cases. In all, 89 patients (27%) were operated on for acute aortic dissection, 77 (23%) for chronic aortic dissection, and 164 (50%) for degenerative aneurysm. Total arch replacement using a branched graft was performed in 288 patients (94%). Mean SCP time was 86.2 +/- 28.5 minutes. RESULTS: The overall in-hospital mortality rate was 11.2% (falling to 3.2% in the 124 patients operated on between 1997 and 2001). Independent determinants of hospital mortality were pump time, renal/mesenteric ischemia, chronic renal failure, increasing age, period of operation, and nonuse of four-branched arch graft. The overall postoperative incidences of temporary and permanent neurologic dysfunction were 4.2% and 2.4%, respectively. There was no significant correlation between SCP time and in-hospital mortality or neurologic outcome. CONCLUSIONS: Selective cerebral perfusion is a reliable technique for cerebral protection and it facilitates complex and time-consuming total arch replacement.

Adolescent↗
PubMed2002

Impact of an aggressive surgical approach on surgical outcome in type A aortic dissection.

BACKGROUND: To evaluate the impact of an aggressive surgical approach on early and late outcome in type A aortic dissection. METHODS: From 1983 to 2001, 240 patients underwent operation for acute (n = 138) and chronic (n = 102) type A aortic dissection. The extent of distal aortic resection included the ascending aorta in 39 (16%) patients, hemiarch (HAR) in 47 (20%), and total arch (TAR) in 154 (64%), including 19 patients who also had their descending aorta replaced (DAR). RESULTS: The in-hospital mortality did not differ between TAR with or without DAR and other more conservative techniques (12.3% versus 16.3%). Actuarial survival at 10 years including in-hospital mortality was 72.4% +/- 3.3% and freedom from reoperation was 77.2% +/- 3.6% for all patients: neither was influenced by the extent of distal aortic resection or acuity of aortic dissection. Multivariate analysis revealed younger age and failure to resect the intimal tear to be independent determinants for late reoperation. However, in contrast to 22 patients who had more conservative operations, none of the patients with TAR required reoperation on the aortic arch through a sternotomy incision. CONCLUSIONS: An aggressive surgical approach did not adversely influence early and late survival following type A aortic dissection; it reduced the necessity of late reoperation and facilitated distal aortic reoperation.

Adult↗
PubMed2002

Histological changes in canine aorta 1 year after stent-graft implantation: implications for the long-term stability of device anchoring zones.

PURPOSE: To examine aortic histology 1 year after stent-graft implantation in a canine model as a means of assessing the durability of endograft fixation. METHODS: Fourteen mongrel dogs each received 1 stent-graft and 1 bare stent placed endoluminally in the abdominal aorta. Eight animals were followed for 1 year, 3 for 4 to 8 weeks, and the remaining 3 for 24 to 48 hours. Aortic specimens were stained with hematoxylin-eosin, elastica-van Gieson, and Masson's trichrome and examined with light and electron microscopy and immunohistochemistry to identify smooth muscle cells (SMC), endothelialization, aortic wall ultrastructure, and changes at the device anchoring sites. RESULTS: No dilatation or dissection was noted at any of the device anchoring sites. The aortic media at 1 year was remarkably decreased in thickness: 891 +/- 196 microm in the control tissue versus 388 +/- 70 microm for the proximal stent-grafted aorta and 457 +/- 148 microm for the bare-stented aortic segment. Other important histological features were reduced elastic lamellae in the stent-grafted aorta versus control (p<0.0001), increased SMC density in the stent-grafted aortic region (p<0.0001 versus control), and absence of inflammatory infiltrate. Complete neointimal covering and endothelialization of the luminal endograft surface were found. SMCs generally showed no ultrastructural features of necrosis. CONCLUSIONS: Aortic stent-grafts induce distinctive histological changes in the aortic wall at 1 year, even when implanted in a healthy aorta. Although there is considerable medial elastin loss, an increased medial SMC density, an exuberant neointima, and a general absence of perigraft inflammation suggest an ongoing process of structural restoration at the device anchoring sites.

Animals↗
PubMed2002

Simultaneous carotid endarterectomy, coronary artery bypass grafting and abdominal aortic aneurysm surgery.

A case with a disease triad of an ulcerative lesion in the left internal carotid artery (LICA), severe coronary insufficiency, and an infrarenal abdominal aortic aneurysm (AAA) is presented in whom we performed simultaneous carotid endarterectomy (CEA), coronary artery bypass grafting (CABG), and Y-graft replacement of the AAA. The operative technique is detailed and justification of the simultaneous approach in such patients is discussed.

Aortic Aneurysm, Abdominal↗