Biomedical subjects
Publications and source records attributed to C G Tribble.
Pain management after thoracic surgical procedures is a difficult clinical problem. A variety of pain management methods are used with variable efficacy. This paper presents an effective method of pleural anesthetic administration using a pleural catheter inserted through a chest tube.
Paraplegia after thoracic aortic aneurysm repair has an incidence of 2.2% to 24%. Oxygen-derived free radicals after reperfusion of an ischemic spinal cord may be partly responsible for neuronal destruction. We studied the effects of polyethylene glycol-conjugated superoxide dismutase (PEG-SOD), a free radical scavenger, as a way of increasing spinal cord tolerance to ischemia. Thirty rabbits underwent 40 minutes of aortic occlusion (a known model of paraplegia). Ten of these animals received 25,000 U/kg of PEG-SOD 24 hours before aortic occlusion and two additional doses of 10,000 U/kg, one before and one subsequent to spinal ischemia. Ten animals received superoxide dismutase in the same dosages as those receiving PEG-SOD. Ten control animals received placebo. All animals were studied for 96 hours, at which time a final neurological examination was performed and the results were recorded. Of the 10 animals treated with PEG-SOD, 2 were completely paralyzed whereas 8 had less (7) or no (1) neurological impairment. Eight of the 10 control animals and 9 of the 10 animals receiving superoxide dismutase were completely paralyzed. None of the control animals or animals receiving superoxide dismutase had a normal neurological examination (p less than or equal to 0.05). Treatment with PEG-SOD before and during occlusion increased the rabbit spinal cord tolerance to a 40-minute ischemic insult. Scavenging free radicals may lessen experimental spinal cord injury.
The hypothesis of the present study is that axillofemoral bypass grafting for acute vascular occlusion has results significantly inferior to an elective procedure. We reviewed 53 patients undergoing primary axillofemoral bypass grafting at the University of Virginia from 1984 to 1989. We found that patients who were admitted with acute vascular occlusion had a higher incidence of perioperative complications (63% vs 26%, p = 0.001), perioperative mortality (26% vs 3%, p less than 0.05), lower graft patency at 1 year (60% vs 90%, p less than 0.05), lower rate of freedom from reoperation in first year (50% vs 82%, p less than 0.01), and lower rates of limb salvage (76% vs 94%, p less than 0.05) than patients undergoing axillofemoral bypass grafting for chronic symptoms or conditions. These two groups did not differ in any of the other risk factors or perioperative characteristics examined. We conclude axillofemoral bypass grafting performed for indications other than acute vascular occlusion is associated with acceptable morbidity, mortality, graft patency, and limb salvage rates.
To assess the morbidity and mortality of preoperative radiation therapy (RT), the authors reviewed 37 consecutive patients who underwent transhiatal esophagectomy for carcinoma of the esophagus. Twelve patients received no RT, 13 patients received RT only to the neck, and 12 received RT to the chest (three of these received radiation therapy to the chest and neck). Preoperative chest RT did not significantly increase postoperative fistula formation but was associated with significantly higher operative mortality, overall complication rate, and time on ventilators than either the patients receiving neck RT alone or no RT (P less than 0.05). Postoperative hospital stay was longer and intraoperative blood loss greater for the chest RT group compared to those with no RT (P less than 0.05). Neck RT did not result in these complications (P = NS). The authors conclude that preoperative chest RT is associated with significant postoperative morbidity and mortality.
Percutaneous transluminal angioplasty was used to treat 340 aortoiliac lesions in 200 patients who were followed for as long as 90 months (mean, 28.7 months; median, 23 months). The initial success rate was 94.7% for lesions and 93.0% for patients. The indications for percutaneous transluminal angioplasty included claudication in 117 patients (58.5%), rest pain or ischemic night pain in 47 (23.5%), limb salvage in 33 (16.5%), and aiding in wound healing in three (1.5%). In the series, 70% of the patients had two or more cardiovascular risk factors. Angioplasty was initially unsuccessful in 14 patients, and 10 patients were lost to follow-up. Follow-up was obtained in 176 patients. The long-term results were analyzed using the life table method to determine cumulative patency. Fourteen patients were considered failures because of recurrent disease or symptoms. The projected 7.5-year cumulative patency rate was 85%. When the response to redilatation was considered, the projected 7.5-year cumulative patency rate was 92%. The results indicate that percutaneous transluminal angioplasty can successfully correct aortoiliac lesions and provide a long-term benefit for as long as 7.5 years.
Lung transplantation is now established as a clinical reality for patients with irreversible, lethal pulmonary conditions. We report the first successful application of this treatment modality in Virginia.
Aneurysms of the iliac arterial system are often difficult to approach surgically. Aortobifemoral (ABF) bypass grafting with exclusion of the aneurysms can be used as an alternative to the usually recommended approach of endoaneurysmorrhaphy. Fourteen patients with iliac artery aneurysms treated by ABF are compared to 16 patients treated by direct repair to compare the incidence of complications related to decreased pelvic blood flow or to the presence of the excluded iliac artery aneurysm. There were no differences between the two groups. Therefore, it is concluded that ABF is a reasonable alternative in the treatment of iliac artery aneurysms.
Standardized reproducible tests have been developed to determine the biomechanical performance of cardiovascular needles. The parameters used to assess performance were: 1) sharpness, 2) resistance to bending, and 3) ductility. Four comparable groups of tapercut and taper point cardiovascular needles were selected from different manufacturers for these biochemical studies. The results of this testing demonstrated that needle geometry, needle composition, and the manufacturer were important determinants of needle performance. When comparable needles were evaluated, the biochemical performance of cardiovascular needles manufactured by Ethicon, Inc. (Somerville, NJ) were superior to needles produced by other manufacturers. The superior performance characteristics of the cardiovascular needles produced by Ethicon, Inc. were related to their unique stainless steel alloy, American Society for Testing Materials 45500, which has greater yield and tensile strengths than the alloy used by the other manufacturers. This stainless steel alloy was ideal for the production of tapercut needles, which combined some of the features of a reverse cutting edge needle and taper point needle. Its very short cutting edges allowed it to penetrate the membrane at considerably lower penetration forces than were encountered with comparable taper point needles. In addition, the investigation indicated that the trocar point cardiovascular needles produced a large triangular defect whose diameter was much larger than that of the needle body. For this reason, the use of the trochar point needle is not recommended in cardiovascular surgery.
A single-donor fibrin sealant system was used in 689 thoracic and cardiovascular surgical procedures over the 4-year period between April 1, 1985, and March 31, 1989. An excellent overall success rate (646/689, 94% effective) was achieved with specific applications, including reduction of leakage of air (29/33, 88% effective), blood (595/634, 94% effective), and fluid (14/14, 100% effective), as well as positioning of anatomical structures such as coronary bypass grafts (8/8, 100% effective). Application methods included use of spray bottles (477/497, 96% effective), syringes (165/186, 89% effective), and a Silastic cannula through the flexible fiber-optic bronchoscope (4/6, 67% effective). The system was used in a wide variety of cardiac, pulmonary, esophageal, and vascular procedures to seal staple lines, suture lines, anastomoses, conduits, fistulas, and raw surfaces. No complications with this single-donor system secondary to blood-borne disease have been documented. Overall infection occurred at a nominal rate (16/689, 2%). Thus, fibrin sealant has been a useful tool to control the leakage of air, blood, and fluid during a wide variety of thoracic and cardiovascular procedures and may be of benefit to other surgeons.
The indications, technique, and results of thoracoscopic talc poudrage in the two clinical settings of pneumothorax and recurrent pleural effusion in chronically ill patients are reported. Forty patients underwent this treatment between May 1982 and September 1989. The patients ranged in age from 10 months to 78 years. Of the 20 patients who underwent treatment of pneumothorax, 9 had cystic fibrosis, 7 had severe chronic obstructive pulmonary disease, 2 had spontaneous pneumothoraces, and 2 had postoperative parenchymal bronchopleural fistulas. Nineteen patients (95%) had successful treatment. Of the 20 patients who underwent treatment of chronic effusions, 14 had malignant etiologies, 3 had chylothoraces, and 3 had other miscellaneous effusions. Eighteen patients (90%) in this group had successful treatment. There were two hospital deaths related to the underlying disease processes after the pleural space problems were successfully treated. This study suggests that proper selection of patients and full exploitation of the capabilities of thoracoscopy and talc poudrage will result in effective treatment with low morbidity and mortality.
Epicardial porous disks were used to estimate left ventricular interstitial fluid adenosine in the isolated guinea pig heart perfused at constant flow. To validate this technique, adenosine was infused with 0.5 microM dipyridamole and 5 microM erythro-4-(2-hydroxy-3-nonyl)adenine hydrochloride (EHNA) to inhibit adenosine uptake and deamination, respectively. Under these conditions, with 6 or 12 microM adenosine in the arterial infusate, the venous and steady-state left ventricular disk adenosine values equaled those of the perfusion fluid, reflecting the expected equilibration between vascular and left ventricular interstitial fluid (disk) compartments. The concentration of endogenous adenosine in the interstitial fluid as estimated by the epicardial disks under control conditions was 0.28 +/- 0.03 microM with a concomitant coronary sinus concentration of 0.004 +/- 0.001 microM. We conclude that a marked adenosine gradient exists between the interstitial fluid and the vascular space and that disk adenosine measurements provide a useful index of left ventricular interstitial fluid adenosine.
Standardized reproducible tests have been developed to determine the biomechanical performance of cardiovascular needles. The parameters used to assess performance were sharpness, resistance to bending, and ductility. Three comparable groups of taper point cardiovascular needles were selected from different manufacturers for these biomechanical studies. The results of this testing demonstrated that needle geometry, needle composition, and the manufacturer were important determinants of needle performance. When needles of comparable size were evaluated, the biomechanical performance of cardiovascular needles manufactured by Ethicon, Inc., were superior to needles produced by other manufacturers. The superior performance characteristics of the cardiovascular needles produced by Ethicon, Inc., were related to their unique stainless steel alloy, American Society for Testing Materials 45500, which has greater yield and tensile strengths than the alloy used by the other manufacturers. Scanning electron microscopic photographs of the Ethicon, Inc., needle revealed a uniform taper point geometry without irregularities. The deformations of the points of cardiovascular needles produced by the other manufacturers could alter their performance.
Both map-guided endocardial resection (ER) and the automatic implantable cardioverter defibrillator (AICD) are currently used for surgical treatment of patients who have sustained ventricular tachyarrhythmias. Some authors have preferred AICD implant due to a lower published operative mortality rate. To determine if there is a discrepancy in mortality rates between the two techniques, we analyzed hospital survival in 46 patients undergoing ER and in 44 patients undergoing AICD implantation during the same 3-year period. Two ER patients (4%) died before hospital discharge. Two patients (4%) died after AICD implantation. At predischarge electrophysiologic study five patients (11%) had inducible ventricular tachycardia and received antiarrhythmic drug therapy after ER. In contrast 35 of 42 patients surviving AICD placement received chronic long-term antiarrhythmic therapy (p less than 0.05 compared to ER). Our experience shows that ER and AICD placement may be carried out with similar procedure-related mortality and morbidity rates. Lower operative risks should not be a reason for choosing the AICD over ER for surgical treatment of ventricular tachyarrhythmias. The AICD may actually improve the results of ER by offering an alternative to ventriculotomy in poor-risk surgical candidates.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
We reviewed the experience at the University of Virginia over the past 10 years with renal tumors involving the inferior vena cava. There were 107 patients with renal tumors, 41 with invasion of the renal vein and 18 with involvement of the inferior vena cava. The groups with and without vena caval tumors were compared, and the operative approach is described. Although the rate of complications was higher in operations on the vena cava, none were fatal and no patient required chronic dialysis. Life-table analysis revealed that patients with involvement of the inferior vena cava survived longer than those with incomplete resection. Because extraction of these tumors can be accomplished with acceptable morbidity and mortality, because complete resection confers a survival advantage, and because chemotherapy and radiation are ineffective, we recommend aggressive workup and resection of renal tumors involving the inferior vena cava.
Between 1968 and 1981, 25 patients with acute traumatic rupture of the aorta were treated at the University of Virginia. Twenty-two of these patients (88%) had serious concomitant injuries. The aortic tear was just distal to the left subclavian artery in 19 patients (76%), and at other sites in six patients (24%). Lacerations were at multiple sites in three patients (12%), in the ascending aorta in one (4%), in the distal aortic arch in two (8%), and in the descending aorta well beyond the subclavian artery in six (24%). Two of the patients (8%) died of free rupture of the aorta before reaching the operating room. The other 23 patients (92%) had operation and 17 (68%) survived. At least ten of the 17 survivors (59%), with an average follow-up of seven years, do not have a disability as a result of the injury. In this group, 24 of the 25 traumatic aortic injuries (96%) occurred in the distal aortic arch or the descending aorta and could be repaired through a left posterolateral thoracotomy.
Explore the source record for details and available documents.