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Biomedical subjects

S Khonsari

Publications and source records attributed to S Khonsari.

At least 19 recordsLinked to original sources
PubMed1995

Stentless porcine aortic root: valve of choice for the elderly patient with small aortic root?

The Medtronic Freestyle bioprosthesis is a stentless porcine aortic root cross-linked in dilute glutaraldehyde solution with stress-free fixation for the valve leaflets. It has been treated by a process in which amino oleic acid is used to reduce the potential for calcification. As a complete aortic root, it has the same versatility as the aortic homograft but has the advantage that it is readily available in all sizes to the implanting surgeon. Between January 1993 and May 1994, we implanted 64 Freestyle bioprostheses as aortic valve replacements using a freehand technique; 5 size 19 mm, 15 size 21 mm, 16 size 23 mm, 13 size 25 mm, and 15 size 27 mm valves were used. There were 35 men and the mean age was 75.7 years (64 to 84 years). The operative mortality was 3.1% (2/64). Echocardiograms at the time of discharge revealed mean aortic valve gradients ranging from 18.2 mm Hg for 19 mm to 10.3 mm Hg for 27 mm valves. Effective orifice areas ranged from 1.0 cm2 for 19 mm to 2.0 cm2 for 27 mm valves. No patient had more than trace aortic insufficiency. Our early experience with this new stentless bioprosthesis shows it to have excellent hemodynamics especially in the smaller valve sizes. Using this valve in patients who have a small aortic root and require a tissue valve avoids the need for aortic root enlargement procedures.

Aged↗
PubMed1994

Gastrointestinal complications associated with cardiopulmonary bypass procedures.

Gastrointestinal complications after cardiopulmonary bypass (CPB) procedures are rare, but when they do occur, they carry a significant incidence of morbidity and mortality. Over a 5-year period spanning 1988-1992, 4923 CPB procedures were performed and 64 patients were identified who suffered a GI complication, giving an incidence of 1.3 per cent. The most frequent complications were GI bleeding (40%) and pancreatitis (34%). Other complications included acute cholecystitis (11%), perforated duodenal ulcer (8%), ischemic bowel (5%), and diverticulitis (2%). Complications occurred most frequently in patients undergoing procedures with longer pump and cross-clamp times, such as valvular and combination (CABG/valve) procedures. Redo procedures and the use of an intra-aortic balloon pump increased the risk of developing a GI complication 2.5 and 12 times, respectively. Patients were treated aggressively both medically and surgically, but suffered a higher mortality (16%) as compared to those not suffering a GI complication (3%). We conclude that GI complications after CPB procedures are infrequent but lethal. Clinical features are often subtle, and a high index of suspicion is needed for early diagnosis and aggressive treatment.

Adolescent↗
PubMed1994

Surgical revascularization after acute myocardial infarction. Does timing make a difference?

At present no consensus exists regarding the timing of surgical revascularization after acute myocardial infarction. Patients admitted with acute myocardial infarction between January 1990 and April 1993 underwent early cardiac catheterization if they had postinfarction ischemia or positive results on a low-level exercise stress test. If indications for surgical intervention were found at the time of catheterization, patients were operated on within 1 or 2 days or were discharged and returned for the operation within 2 to 3 weeks. During this period, we performed 2175 isolated coronary artery bypass graft procedures; 23 patients were operated on within 24 hours of acute myocardial infarction with an operative mortality of 4.4%, 30 patients underwent surgery between 24 and 72 hours after infarction with no deaths, 193 patients were operated on between 3 and 7 days after infarction with an operative mortality of 2.1%, 284 patients underwent revascularization between 1 week and 1 month after infarction with an operative mortality of 1.4%, and the 1645 patients without a recent infarction had a mortality rate of 1.9%. Multivariate statistical analysis was performed to evaluate mortality with these independent variables: reoperative surgery, sex, age, diabetes, timing of infarction, location of infarction, and type (transmural versus subendocardial). Myocardial infarction at any time interval less than 1 month before the operation was not associated with mortality when adjusted by these other risk factors. In addition, no differences were noted in length of stay, stroke rate, or prevalence of renal failure or pulmonary insufficiency. We conclude that nonemergency surgical revascularization can be done safely at any time interval after acute myocardial infarction, certainly after 72 hours, with no increase in operative mortality and acceptable morbidity.

Aged↗
PubMed1990

Transatrial approach revisited.

A surgical approach is described to provide excellent exposure of the interior of the left atrium and the mitral valve apparatus.

Heart Atria↗
PubMed1986

Disruption of the ascending aorta: surgical management.

A disruptive injury to the ascending aorta during a cardiac operation is a serious and often fatal event. Such an injury is described in which the aorta disrupted at the site of the proximal aortocoronary anastomoses. It was possible to repair the aorta using an intraluminal sutureless graft after other techniques of repair failed.

Aged↗
PubMed1983

Coronary bypass operation following acute complicated myocardial infarction.

The indications for operation to correct acute mechanical defects after myocardial infarction are clearly established. Less clear is the use of surgical procedures for nonmechanical complications such as persistent ischemia or circulatory collapse. Between 1974 and 1981, 80 patients underwent coronary artery bypass grafting (CABG) within 2 weeks of infarction. Continued pain was the indication in 83% and cardiogenic shock in 17%. Seventeen patients were operated upon within 24 hours of infarction, 35 from 1 to 7 days, and 28 from 8 to 14 days. Eighty-one percent were men; mean age was 58 years. In 39% of patients the infarction was the premier symptom of coronary artery disease. Sixty-two percent had impaired left ventricular function as judged by left ventricular end-diastolic pressure greater than 15 mm Hg or abnormal wall motion seen on ventriculogram. Overall operative mortality was 5.0%; early mortality by indication was 3.0% for pain and 14.3% for shock. Operation for pain carried a 7.7% mortality if done within 48 hours of infarction and was 0% for those patients operated upon after that time. The status of 90% of all patients was known as of December, 1981, with a mean follow-up of 2.9 years. Life-table analysis demonstrates a 5 year survival rate of 85% +/- 6% in the group operated upon for pain. CABG in the immediate postinfarction period can be done safely with a 5 year survival in patients without hemodynamic compromise comparable to that of patients with chronic angina undergoing elective operation. These results should encourage the application of early postinfarction CABG in other high-risk subgroups of patients.

Angina Pectoris↗
PubMed1983

Mitral repair in complete atrioventricular canal. Ease of correction in early infancy.

During the past 5 years all patients with complete atrioventricular (AV) were subjected to surgical correction regardless of age. Thus we were able to assess the ease and reliability of mitral repair in early infancy. Key features of operation include division of bridging leaflets when indicated, selection of a patch sufficiently small to prevent postoperative annular dilation, attachment of the leaflets to the patch with continuous nonpledget-supported sutures at a level determined by the chordal structure, and, based on the size of the mural leaflet, construction of a bicuspid or tricuspid mitral valve. Operative mortality and postoperative morbidity were no greater in patients under 6 months of age than in older patients. Reoperation for mitral regurgitation was required in three patients. In all of them, the primary reason for the failure of repair was that the mitral valve had been left tricuspid; in two of them, the mitral anulus was dilated, as well. Repair was uniformly accomplished by bicuspidization, combined in two instances with a Wooler-type annuloplasty and shortening of the free margin of the aortic leaflet. The absence of secondary scarring of the leaflets in the patients under 6 months of age facilitated repair in this age group. Early repair is possible, and preferable, provided that meticulous attention is paid to the technical features of the repair and a proper decision is made with regard to treatment of the mitral "cleft."

Aging↗
PubMed1982

Common pulmonary vein atresia: Importance of immediate recognition and surgical intervention.

Common pulmonary vein atresia is a rare congenital anomaly; all four pulmonary veins drain into a common dilated chamber with no direct connections to the heart or systemic venous system. Since its first description in 1962, 16 cases have been reported. Only four patients were surgically managed and none survived. This communication presents the seventeenth reported case of common pulmonary vein atresia and the only patient whose anomaly was suspected early enough to demand immediate surgical management, with gratifying long-term success. The literature on the subject is reviewed and common features of the anomaly are emphasized to facilitate precise diagnosis, so that a futile search for a nonexistent communicating vein is avoided at the time of operation. This approach has led to the first successful surgical management of this otherwise fatal lesion.

Heart Atria↗
PubMed1976

Calcified right ventricular fibroma causing outflow obstruction. Report of a case with successful excision.

A 5-year-old boy with clinical findings of pulmonic stenosis was found to have a large calcified mass in the right ventricular outflow region and a gradient of 120 mm Hg between the right ventricle and the pulmonary artery. At surgery, an ovalshaped tumor attached to the interventricular septum and obstructing the right ventricular outflow tract was removed. The child survived and is doing well. Histologically, the tumor had the characteristics of fibroma. A hemodynamic study three months after surgery showed almost complete abolishment of the gradient. To our knowledge this is the fifth reported case of calcified right ventricular fibroma with successful operation. In childhood intracardiac calcifications, together with obstruction, are highly suggestive of this lesion.

Angiocardiography↗