Blair A. Keagy

A strategy to increase the donor pool: use of cadaver lungs for transplantation.

A shortage of suitable donors is a serious obstacle to the widespread application of isolated lung transplantation for end-stage lung disease. We hypothesized that lung tissue likely remains viable for a sufficient period of time to allow for safe postmortem retrieval of lungs for transplantation. Studies were conducted in a nonsurvival model of canine lung allotransplantation. Donor animals were sacrificed, and subsequent lung harvest was delayed for 1 hour, 2 hours, or 4 hours. Pulmonary retrieval was then performed in a standard fashion, flushing the lung block with modified Euro-Collins solution. Lungs were then stored for 4 hours before single allotransplantation. Recipient animals were maintained anesthetized, and followed up for 8 hours. By occlusion of the pulmonary artery and bronchus to the native lung, recipient animals were forced to survive solely on the transplanted lung, with a constant inspired oxygen fraction of 0.40. All 5 recipient animals of 1-hour cadaver lungs survived the 8-hour observation period with excellent hemodynamics and gas exchange. Two of 5 recipients of 2-hour cadaver lungs survived the observation period, whereas a third animal survived for 5 hours with excellent gas exchange. One of 4 animals transplanted with a 4-hour cadaver lung survived the observation period. Retrieval of lungs from cadavers whose hearts are not beating may prove to be a safe and effective method to increase the pulmonary donor pool.

Healing rates and cost efficacy of outpatient compression treatment for leg ulcers associated with venous insufficiency

OBJECTIVE Although newer techniques to promote the healing of leg ulcers associated with chronic venous insufficiency are promising, improved healing rates and cost effectiveness are unproven. We prospectively followed a series of patients who underwent treatment with outpatient compression for venous stasis ulcers without adjuvant techniques to determine healing rates and costs of treatment. METHODS Two hundred fifty-two patients with clinical or duplex scan evidence of chronic venous insufficiency and active leg ulcers underwent treatment with ambulatory compression techniques. The patients were prospectively followed with wound measurements at 1-week to 2-week intervals, and the factors that were associated with delayed healing were determined. RESULTS Of all the ulcers, 57% were healed at 10 weeks of treatment and 75% were healed at 16 weeks. Ultimately, 96% of the ulcers healed, and only 1 major amputation was necessitated (0.4%). Initial ulcer size and moderate arterial insufficiency (ankle brachial index, 0.5 to 0.8; n = 34) were factors that were independently associated with delayed healing (P <.01). Patient age, ulcer duration before treatment, and morbid obesity did not significantly affect healing times. The cost of 10 weeks of outpatient treatment with compression techniques ranged from

Carotid artery trauma: A review of contemporary trauma center experiences☆☆☆★

1444 to

Elective Pulmonary Lobectomy: Factors Associated with Morbidity and Operative Mortality

2711. CONCLUSION The treatment of venous stasis ulcers with compression techniques results in reliable, cost-effective healing in most patients. Current adjuvant techniques may prove to be useful but are likely to be cost effective only in a minority of cases, particularly in patients with large initial ulcer size or arterial insufficiency.

Prospective randomized comparison of surgical versus endovascular management of thrombosed dialysis access grafts

PURPOSE Many issues surrounding the management and outcome of carotid artery injuries remain controversial. The purpose of this study was to review a large contemporary experience with such injuries in the setting of designated trauma centers. METHODS A statewide computerized trauma registry was used to identify all patients with injuries to the common or internal carotid arteries from October 1987 to June 1993. The records of 82 such patients were retrieved and analyzed. RESULTS Overall mortality and stroke rates were 17% and 28%, respectively. Patients presenting with coma or shock had a particularly bad prognosis (50% and 41% mortality, respectively). Internal carotid injuries resulted in mortality and stroke rates of 21% and 41%, respectively, compared with 11% each for common carotid injuries. Patients with blunt injuries had a much higher stroke rate (56% vs 15%) but had lower mortality (7% vs 22%) than did patients with penetrating injuries. Airway compromise and associated injuries did not affect prognosis. Operative repair and percutaneous balloon occlusion had the best survival and functional outcomes. CONCLUSIONS Operative repair offers the best chances for recovery in all categories of patients regardless of injury mechanism. Ligation is useful only as a last-resort lifesaving effort. Shock and neurologic impairment are poor prognostic factors but should not negate repair.

The role of air plethysmography in the diagnosis of chronic venous insufficiency

Periodic review of clinical results is essential to ensure that high-quality patient care is maintained. To that end, we reviewed the morbidity and operative mortality in a consecutive series of 369 pulmonary lobectomies performed between January 1, 1970, and December 31, 1983. There were 251 male and 118 female patients with a mean age of 50.6 years. The thirty-day operative mortality was 2.2% (8/369), with 6 of these deaths related primarily to respiratory insufficiency. Two hundred twenty-four postoperative management problems occurred in 151 patients and included arrhythmia, air leak, pneumothorax, respiratory difficulties, postoperative bleeding, pleural effusion, wound infection, myocardial infarction, pulmonary embolus, empyema, bronchial stump leak, and lobar gangrene. Multiple factors were related to the occurrence of postoperative morbidity and mortality using both chi-square analysis to examine each individual item and discriminant analysis to evaluate their interaction. Chi-square tabulation showed no difference in the occurrence of major postoperative complications (p greater than 0.05) related to the side of operation, an abnormal preoperative electrocardiogram, a forced vital capacity of 2.8 liters or less, a one-second forced expiratory volume (FEV1) of less than 1.7 liters, an oxygen tension of less than 60 mm Hg, or the seniority of the surgeon (resident versus attending). An increased number of complications (p less than 0.05) was found in male patients, in patients operated on for carcinoma, and in patients older than 60 years. Stepwise discriminant analysis included FEV1 as a significant predictor of postoperative complications.(ABSTRACT TRUNCATED AT 250 WORDS)

Inflammatory cytokine levels in chronic venous insufficiency ulcer tissue before and after compression therapy

PURPOSE Salvage of thrombosed prosthetic dialysis shunts can be performed using surgical or endovascular techniques. A prospective randomized trial was designed to compare the efficacy of these two methods in restoring dialysis access function. METHODS One hundred fifteen patients with thrombosed dialysis shunts were randomized prospectively to surgical (n = 56) or endovascular (n = 59) therapy. In the surgical group, salvage was attempted with thrombectomy alone in 22% and with thrombectomy plus graft revision in 78%. In the endovascular group, graft function was restored with mechanical (82%) or thrombolytic (18%) graft thrombectomy followed by percutaneous angioplasty. RESULTS Stenosis limited to the venous anastomotic area was the cause of shunt thrombosis in 55% of patients, and long-segment venous outflow stenosis or occlusion was the cause in 30%. In 83% of the surgical group and in 72% of the endovascular group, graft function was immediately restored (p = NS). The postoperative graft function rate was significantly better in the surgical group (p < 0.05). Thirty-six percent of grafts managed surgically remained functional at 6 months and 25% at 12 months. In the endovascular group, 11% were functional at 6 months and 9% by 12 months. Patients with long-segment venous outflow stenosis or occlusion had a significantly worse patency rate than those with venous anastomotic stenosis (p < 0.05). CONCLUSIONS Neither surgical nor endovascular management resulted in long-term function for the majority of shunts after thrombosis. However, surgical management resulted in significantly longer primary patency in this patient population, supporting its use as the primary method of management in most patients in whom shunt thrombosis develops.

Lower extremity amputation: The control series

PURPOSE The role of air plethysmography (APG) in the diagnosis of venous disease is not well defined. We conducted this study to investigate the value of APG in the diagnosis of chronic venous insufficiency and to determine its correlation with the clinical severity of disease and the anatomic distribution of reflux. METHODS We studied 186 lower extremities with duplex scanning and venography and measured the venous volume, venous filling index (VFI), ejection fraction, and residual volume fraction with APG. Limbs were categorized according to the Society for Vascular Surgery and International Society for Cardiovascular Surgery classification of clinical severity of disease and according to the anatomic distribution of valvular incompetence. RESULTS Sixty-one limbs had no evidence of disease (class 0), 60 limbs had mild disease (classes 1, 2, and 3), and 65 limbs had severe disease (classes 4, 5, and 6). According to the results of duplex scanning and venography, there was no evidence of reflux in 56 limbs. Isolated superficial venous reflux occurred in 52 limbs, and perforator reflux, alone or in conjunction with superficial reflux, occurred in 30. Deep reflux, with or without superficial reflux, was found in 25 limbs. Deep and perforator reflux, with or without superficial reflux, was found in 19 limbs. The VFI had a sensitivity of 80% and 99% positive predictive value for any type of reflux. The VFI was significantly different between groups of limbs with different clinical severities of disease or different types of reflux. The incidence of deep or perforator reflux in limbs with a normal VFI value was 7%, and it was 82% in limbs with a VFI of more than 5. Among 86 limbs with VFI values not corrected with use of a thigh tourniquet, 28% did not have evidence of deep or perforator reflux, and among 15 limbs with VFI values corrected with the use of a tourniquet, 33% had perforator reflux, deep reflux, or both. All APG parameters had low positive predictive values for severe disease or ulceration. The ejection fraction and residual volume fraction did not influence the clinical severity of disease, did not discriminate between types of reflux, and in combination with the VFI did not improve the predictive value of APG. CONCLUSIONS The VFI measured by APG is an excellent predictor of venous reflux, provides an estimate of the clinical severity of disease, and at high levels predicts deep reflux, perforator reflux, or both. Correction of an abnormal VFI with a thigh tourniquet is an unreliable predictor of the absence of deep or perforator incompetence. The predictive value of APG for severe disease or ulceration is poor. The ejection fraction and residual volume fraction, individually or in combination with the VFI, add little to the diagnostic value of APG, and their routine performance may not be clinically justified.

Proximal venous outflow obstruction in patients with upper extremity arteriovenous dialysis access

OBJECTIVE Elevated inflammatory cytokine levels have been implicated in the pathogenesis of non-healing chronic venous insufficiency (CVI) ulcers. The goal of this study was to determine the protein levels of a wide range of inflammatory cytokines in untreated CVI ulcer tissue before and after 4 weeks of high-strength compression therapy. These levels were compared to cytokines present in healthy tissue. METHODS Thirty limbs with untreated CVI and leg ulceration received therapy for 4 weeks with sustained high-compression bandaging at an ambulatory wound center. Biopsies were obtained from healthy and ulcerated tissue before and after therapy. A multiplexed protein assay was used to measure multiple cytokines in a single sample. Patients were designated as rapid or delayed healers based on ulcer surface area change. RESULTS The majority of pro-inflammatory cytokine protein levels were elevated in ulcer tissue compared to healthy tissue, and compression therapy significantly reduced these cytokines. TGF-beta1 was upregulated in ulcer tissue following compression therapy. Rapid healing ulcers had significantly higher levels of IL-1alpha, IL-1beta, IFN-gamma, IL-12p40, and granulocyte macrophage colony stimulating factor (GM-CSF) before compression therapy, and IL-1 Ra after therapy. IFN-gamma levels significantly decreased following therapy in the rapidly healing patients. CONCLUSION CVI ulcer healing is associated with a pro-inflammatory environment prior to treatment that reflects metabolically active peri-wound tissue that has the potential to heal. Treatment with compression therapy results in healing that is coupled with reduced pro-inflammatory cytokine levels and higher levels of the anti-inflammatory cytokine IL-1 Ra.

Correlation of Preoperative Pulmonary Function Testing with Clinical Course in Patients after Pneumonectomy

Although various techniques to determine amputation level have become available, obvious clinical factors may yet identify patients in whom a major amputation is unlikely to heal. We have analyzed the association of multiple clinical factors with the morbidity of 1028 consecutive amputations performed in 786 patients during a 13-year period. The overall operative mortality rate was 7% (57 of 786 patients). Cardiac complications were the leading cause of death (43%). In the 729 patients surviving operation, 345 above-knee amputations (AKAs) and 626 below-knee amputations (BKAs) were performed. After operation, 15.4% of these amputations failed to heal and required proximal revision. The AKA failure rate was 9% and the BKA failure rate was 19%. Significantly higher failure rates were noted in whites, nondiabetics, and those patients with heart disease. It is concluded that major amputation continues to be associated with significant morbidity and mortality rates despite changes in perioperative care and surgical technique. Common clinical characteristics indicate high-risk patients in whom a BKA is unlikely to heal and who may benefit from prospective attempts to determine amputation level.