Search PubMed⌕ Search

Biomedical subjects

J R Doty

Publications and source records attributed to J R Doty.

33 records · Page 2Linked to original sources
PubMed1998

Aortic valve replacement with medtronic freestyle bioprosthesis: operative technique and results.

OBJECTIVE: This study evaluates the initial results for safety and efficacy of aortic valve replacement (AVR) using the Medtronic Freestyle Bioprosthesis. METHODS: One hundred three patients underwent AVR with the Medtronic Freestyle Bioprosthesis over a 40-month period. There were 59 male and 44 female patients with a mean age of 74 years (range 36 to 88 years). Valve size ranged from 19 to 27 mm, and all valves were implanted using a freehand subcoronary technique. Anticoagulation with coumadin was only used for atrial fibrillation. Aspirin was given to patients with associated coronary artery disease. Echocardiography to assess transvalvular pressure gradient and effective valve orifice area was performed at discharge, 3 to 6 months, 1 year, and then annually. RESULTS: There were 4 (3.9%) deaths within 30 days of operation and 5 (4.9%) late deaths. Two (1.9%) deaths were valve-related, one from commissural dehiscence and one from bacterial endocarditis. Three (2.9%) deaths, two early and one late, were from other cardiac causes. The remaining deaths were from noncardiac causes. Five (4.9%) patients suffered a thromboembolic event, two had permanent neurological deficits, two had transient neurological events, and one had coronary artery occlusion. Mean transvalvular gradient assessed by echocardiography was low at all time intervals: discharge (12.8 mmHg), 3 to 6 months (11.3 mmHg), 1 year (12.0 mmHg), and 2 years (11.6 mmHg). Mean effective valve orifice area was good at all time intervals: discharge (1.4 cm2), 3 to 6 months (1.5 cm2), 1 year (1.6 cm2), and 2 years (1.6 cm2). Of the 38 patients assessed by echocardiography at 1 year, 33 (87%) had no or trivial valve incompetence and the remainder had mild valve incompetence. CONCLUSIONS: Aortic valve replacement with the Medtronic Freestyle Bioprosthesis has a low incidence of early valve-related mortality and thromboembolism. The bioprosthesis demonstrates good hemodynamic performance even in small diameters and is particularly well suited for older patients and the small aortic root.

Adult↗
PubMed1998

Clinical experience with image-guided robotic radiosurgery (the Cyberknife) in the treatment of brain and spinal cord tumors.

The Cyberknife is an image-guided "frameless" dedicated radiosurgical device. This instrument has several distinct advantages over frame-based systems, including improved patient comfort, increased treatment degrees of freedom, and the potential to target extracranial lesions. Clinical results thus far with respect to the treatment of malignant intracranial tumors has been promising. Additionally, the Cyberknife will likely revolutionize the application of radiosurgery to extracranial sites. A description of the components, treatment planning, and clinical results of the Cyberknife will be reviewed.

Arteriovenous Malformations↗
PubMed1998

Surgical education via the Internet: the Cardiothoracic Surgery Network.

The Cardiothoracic Surgery Network is an international collaborative effort among cardiothoracic surgeons that provides a common platform for the exchange of information. The Cardiothoracic Surgery Network website provides peer-reviewed journals, multimedia applications, and a database repository.

Education, Medical, Graduate↗
PubMed1997

Cost analysis of current therapies for limited coronary artery revascularization.

BACKGROUND: Single or double (limited) coronary artery revascularization using percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass (CAB) surgery has recently been enhanced with further innovation in intracoronary stenting and the emergence of minimally invasive direct coronary artery bypass (MIDCAB) grafting. Resource allocation for all modalities is directly dependent on hospitalization costs, length of stay, and clinical results. METHODS AND RESULTS: Four groups of 25 consecutive patients over 9 months at a single center received either PTCA, stenting, MIDCAB, or conventional CAB for single-vessel coronary disease, primarily of the left anterior descending circulation. Day, supply, and procedural charges were evaluated, along with the total hospital charge. Postprocedural length of stay was calculated and compared with a national database. MIDCAB surgery day charges were less than stenting but greater than PTCA, MIDCAB supply charges were the least of all groups, and MIDCAB procedural charges were less than for conventional CAB. Total charges for MIDCAB grafting were less than for stenting but greater than for PTCA. Postprocedural length of stay for MIDCAB patients was equivalent to PTCA patients and significantly less than for stenting or for conventional CAB. CONCLUSIONS: MIDCAB grafting provides a new surgical approach that is comparable in charges to catheter-based interventions. The technique markedly reduces length of stay and perioperative morbidity. The selection of medical or surgical limited coronary revascularization can now be based primarily on clinical outcomes without consideration for associated resource allocation.

Aged↗
PubMed1997

Lateral MIDCAB grafting via limited posterior thoracotomy.

OBJECTIVE: Minimally invasive direct coronary artery bypass (MIDCAB) is a technique for coronary artery bypass grafting performed under direct vision without sternotomy or cardiopulmonary bypass. The approach has been used principally for primary single vessel grafting of the anterior or inferior coronary circulation. This initial experience presents a new lateral technique for patients with isolated circumflex coronary disease which can be used for both primary and reoperative revascularization with either saphenous vein or a free radial artery conduit. METHODS: Lateral MIDCAB grafting of the circumflex coronary circulation was accomplished over a 33 month period at a single center using saphenous vein or free radial artery as the bypass conduit. Through a limited posterior thoracotomy, the lung is deflated and reflected superiorly. The pericardium is opened below the phrenic nerve to expose an obtuse marginal branch of the circumflex coronary artery. After heparinization, the coronary artery is temporarily occluded proximally and distally with local immobilization and an arteriotomy is performed. The distal anastomosis with running suture is followed by the proximal anastomosis on the descending aorta below the hilum of the lung using a side-biting clamp and radiopaque marker. Intraoperative transit time ultrasound flow measurements confirm adequate graft flow before wound closure. RESULTS: To date, 19 patients have undergone this procedure with a mean follow-up of 12 months. A total of 12 patients received saphenous vein grafts and 7 patients received radial artery grafts. There was one death from arrhythmia on postoperative day 9. There was one elective conversion to conventional sternotomy due to inadequate exposure. Graft flows averaged 33.3 cc/min (range 5-87) and the mean postoperative length of stay was 4.5 days; 4 patients underwent recatheterization; 1 had graft occlusion and 2 received late postoperative catheter-based interventions. All patients are currently free of symptoms. CONCLUSIONS: Lateral MIDCAB grafting provides focused revascularization to the circumflex distribution in both primary and reoperative settings. This approach avoids the hazards of resternotomy, eliminates cardiopulmonary bypass, and hastens postoperative recovery. These early results suggest the technique is effective at relieving symptoms and minimizing perioperative morbidity. Further experience at multiple centers will serve to define the ultimate capabilities of this new approach.

Adult↗
PubMed1990

Bypass of superior vena cava. Fifteen years' experience with spiral vein graft for obstruction of superior vena cava caused by benign disease.

Nine patients had operations for obstruction of the superior vena cava with superior vena caval syndrome caused by benign disease. Three patients had fibrosing mediastinitis, four had fibrosing mediastinitis with caseous necrosis, one had thrombosis of the superior vena cava around a pacemaker electrode, and one had spontaneous thrombosis of the superior vena cava. Patients ranged in age from 25 to 68 years. All bypass operations were performed with a composite spiral vein graft constructed from the patient's own saphenous vein, split longitudinally and wrapped around a stent in spiral fashion. The edges of the vein were sutured together to form a large conduit ranging in diameter from 9.5 to 15.0 mm. Six grafts were from the left innominate vein and three grafts were from the internal jugular vein. The grafts were placed into the right atrial appendage in all except one case, in which the graft was to the distal superior vena cava. Follow-up extends from 1 to 15 years. One patient required reoperation at 4 days for thrombosis at the innominate vein-graft anastomosis. Resection of the anastomosis and reconstruction of the graft rendered the patient symptom free. Two grafts closed during the first year after operation. One patient had advancing fibrosing mediastinitis, and a second bypass graft from the external jugular veins remain patent. Another patient had recurrence of spontaneous venous thrombosis. Thus seven of nine grafts remain patent for up to nearly 15 years and all but one patient is free of superior vena caval syndrome. These data show that bypass of the obstructed superior vena cava with a spiral vein graft relieves superior vena caval syndrome and demonstrate long-term patency of the graft.

Adult↗
PubMed1989

Occult intrasacral meningocele: clinical and radiographic diagnosis.

We evaluated four patients who had occult intrasacral meningocele with multimodality radiographic imaging techniques. The clinical features, radiological findings, gross appearances of the lesion at surgery, surgical technique, histopathological features of the cyst wall, and surgical outcome are described. The role of magnetic resonance imaging in the preoperative evaluation compared with standard radiographic techniques is discussed. Theories regarding the pathogenesis of this lesion are reviewed.

Female↗
PubMed1988

Intraoperative monitoring of evoked potentials with a spiral scalp electrode. Technical note.

Monitoring evoked potentials from the brain for prolonged periods during neurosurgical procedures ideally requires attached scalp electrodes that may be placed in a sterile field. The limitations of conventional surface and percutaneous electrodes in the operating room environment have led to the development of a disposable curved-needle electrode which is inherently self-retaining. Clinical results have demonstrated the advantages of this new electrode over other electrodes currently used for intraoperative neurophysiological monitoring.

Electrodes↗
PubMed1988

Surgical excision of a cavernous hemangioma of the rostral brain stem: case report.

A 23-year-old pregnant woman presented with sudden diplopia, ataxia, hemiparesis, and headache secondary to a brain stem hemorrhage. Magnetic resonance imaging (MRI) revealed a hematoma associated with a probable cavernous hemangioma of the rostral brain stem. In this report, we discuss the MRI findings leading to the preoperative diagnosis, as well as the surgical techniques involved in the successful resection.

Adult↗
PubMed1986

Heparin-associated thrombocytopenia in the neurosurgical patient.

Although thrombocytopenia occurs in approximately 10% of medical patients who receive heparin, this complication has not been described in neurosurgical patients. We report the clinical course of two patients who in the immediate postoperative period developed heparin-associated thrombocytopenia that resulted in significant morbidity. In these two cases, the origin of the heparin was in "flush" solutions used to maintain the patency of indwelling vascular catheters and was infused at a dose of 250 to 500 units/day. The minimal daily dose previously reported to result in thrombocytopenia is 9000 units/day administered in divided doses subcutaneously. The case reports indicate that heparin in "flush" solutions should be considered as a cause for unexpected thrombocytopenia and that platelet counts should be monitored in patients receiving heparin in any amount.

Adult↗
PubMedDate not supplied

Cardiac valve operations using a partial sternotomy (lower half) technique.

BACKGROUND AND AIM: Operations on cardiac valves are being performed more frequently through smaller incisions than traditional midline sternotomy. A variety of alternate incisions have been used, but most of the interest appears to focus on partial sternotomy. The purpose of the study was to review results using a partial lower sternotomy for cardiac valve operations. METHODS: A standard partial lower one-half or two-thirds sternotomy was used for cardiac valve operations in 112 patients. The sternum was divided transversely in the third or second intercostal space and vertically from that point through the xyphoid process. Standard instruments and retraction devices were used. This incision provided adequate exposure for even complex operations to be performed. Small cannulae were placed into the aorta and heart through the primary incision for cardiopulmonary bypass. Vacuum-assisted venous drainage was used. RESULTS: Seventy-four single valve operations were performed. There were 35 double valve and 5 triple valve operations (35.4%) performed. Operative mortality (5.3%) and major complication rates were comparable to full the sternotomy approach. CONCLUSIONS: Partial sternotomy (lower half) provides a smaller incision through which virtually all cardiac valve operations may be performed. Results achieved with this approach are similar to those associated with full sternotomy. The smaller incision is appreciated by patients.

Adolescent↗