Influence of graft ischemic time on outcomes following lung transplantation.

BACKGROUND: Reperfusion injury is the most common cause of early mortality following lung transplantation. Although cold graft ischemic time has been reported to influence this injury, some lung grafts with short ischemic times develop significant reperfusion injury, whereas other grafts with more prolonged ischemic times do not develop injury. Our hypothesis was that ischemic time did not significantly influence reperfusion injury or other outcomes following lung transplantation. METHODS: Data on 136 patients who had lung transplantation over a 10 year period was used for analysis. RESULTS: Cold graft ischemic time > or = 6 hours did not increase the risk of reperfusion injury, acute rejection, cytomegalovirus infection, bacterial or fungal pneumonia, bronchiolitis obliterans syndrome, 1-month mortality, 1-year mortality, or 5-year mortality compared with ischemic times of either < 4 hours or 4 to 6 hours. The incidence of reperfusion injury was at least 20% for each time group. CONCLUSIONS: At least 20% of all patients will develop reperfusion injury regardless of cold graft ischemic time. Prolonged ischemic times up to 8 hours do not result in a significant increase in adverse short-term, intermediate, or long-term outcomes. Cautious extension of ischemic time beyond the current target of 4 to 6 hours may be warranted for geographic expansion of the donor lung pool.

Carotid arteriography impacts carotid stenosis management.

Recent literature advocates carotid endarterectomy on duplex alone. The authors hypothesized that carotid angiography adds information that alters clinical management in a substantial number of patients compared to the use of carotid duplex examination alone. The records of 182 consecutive patients who underwent carotid artery duplex and subsequent carotid/cerebral angiography for suspected carotid artery stenosis between January 1998 and April 1999 were reviewed retrospectively. Carotid artery duplex examinations were stratified based on stenosis: < or =39%, 40% to 59%, 60% to 79% (moderate), 80% to 99% (severe), 100%. Carotid stenosis on angiograms was determined by NASCET criteria. New information found at angiography included vertebral, subclavian, or arch atherosclerosis, intracranial pathosis, or a change in duplex stenosis category to a degree of stenosis not requiring surgery. Clinical importance was attributed to angiograms that altered the patients' management plan. Angiography provided additional information in 53% (97/182) of patients. Vertebral disease was found in 25.1%, subclavian disease in 16.4%, intracranial disease in 15.3%, aortic arch disease in 3.3%. Patient treatment was altered in 30% (55/182). Angiographic findings downgraded the stenosis to medical therapy in 20.9% (38/182). The surgical plan was influenced in 5.5% (10/182). Nine intracranial aneurysms were discovered. Carotid angiography was essential for vascular bypass surgery planning in 3.3% (6/182). Angioplasty was performed in 2.2% (4/182). The accurate determination of stenosis is critical in determining optimal treatment of patients with carotid artery stenosis. Routine carotid angiography remains valuable in the clinical treatment of these patients.

A technique for the treatment of sternal infections using the Vacuum Assisted Closure device.

BACKGROUND: Sternal infections after median sternotomy remain a serious cause of postoperative morbidity and mortality. The treatment of sternal infections has evolved over the past few decades, and now aggressive surgical debridement with rotational muscle flap closure has provided an acceptable means of managing this complication. However, there are several disadvantages with this approach, mainly related to the morbidity associated with serial debridements with dressing changes and open packing until the wound is closed. Other disadvantages include potential morbidity and mortality associated with the shearing forces between the beating heart and the debrided sternal edges, and the need to paralyze the patient during the period after debridement. METHODS: Our method of managing sternal infections is based on the triad of prompt surgical debridement, serial quantitative wound cultures, and the use of the Vacuum Assisted Closure (VAC) device (KCI International, San Antonio, TX). Following debridement and irrigation, a biopsy of the healthy appearing bone is sent for quantitative culture. If culture results are favorable, the wound is then fitted with the VAC device, which consists of a non-collapsible, open-cell, polyurethane sponge with embedded vacuum tubing, a vacuum pump, and transparent adhesive dressing. When systemic signs of infection and quantitative cultures indicate the resolution of the local infection, regional muscle flap or primary wound closure is performed. CONCLUSIONS: The VAC serves as a bridge to sternal wound closure and is a safe and effective therapeutic strategy for patients with impaired physiologic reserve and/or highly contaminated wounds. We feel that it is also reasonable to consider the VAC as a preventive strategy against right ventricular rupture. Furthermore, because the firmness of the vacuum sponge apparatus acts as an impressive sternal stabilizer, post-debridement extubation is possible, reducing the need for prolonged paralysis and mechanical ventilation. This stabilization also allows early postoperative ambulation with the VAC in place. In summary, we believe that the VAC device offers an effective means of managing patients with sternal infections.

Epidermal growth factor receptor up-regulation is associated with lung growth after lobectomy.

BACKGROUND: We hypothesized that compensatory lung growth after lobectomy is characterized by a combination of cellular hyperplasia and hypertrophy and that up-regulation of epidermal growth factor receptor (EGFR) is involved in these processes. METHODS: Age-matched mature pigs were divided into four groups. The control group (group C) did not have operation. Two groups underwent left upper lobectomy and were studied 2 weeks (group L2) or 3 months (group L3) later. The last group underwent a sham left thoracotomy, and the left lower lobe was harvested 2 weeks later for EGFR analysis. Left lower lobes were studied using wet weight, cell proliferation index through immunostaining for 5-bromo-2'-deoxyuridine, morphometry, and Western blot analysis for EGFR. Content of protein and DNA (deoxyribonucleic acid) in the lung tissue was also determined. RESULTS: Left lower lobe weights were elevated in both groups L2 and L3 compared with group C. We noted a significant rise in the proliferation index, with a concomitant increase in EGFR expression, in group L2 compared with group C. In group L3, there was an increase in the protein to DNA ratio compared with group C. CONCLUSIONS: We conclude that compensatory lung growth after lobectomy comprises an early increase in the cell proliferation index (ie, cellular hyperplasia) and a late increase in the protein to DNA ratio (ie, cellular hypertrophy). The early proliferative phase is associated with EGFR up-regulation.

Adenosine analogue reduces spinal cord reperfusion injury in a time-dependent fashion.

BACKGROUND: We hypothesized that inflammation during spinal cord reperfusion worsens ischemic injury. ATL-146e, an adenosine A(2A) agonist with known anti-inflammatory properties, was used to test this hypothesis at varied intervals to determine the time course of reperfusion injury. METHODS: Forty rabbits underwent cross-clamping of the infrarenal aorta for 45 minutes. One group (n = 14 animals) received 0.06 microg/kg/min systemic ATL-146e over 3 hours, beginning after 30 minutes of ischemic time. A second group (n = 6 animals) received ATL-146e over 1.5 hours. A third group (n = 3 animals) received ATL-146e over 1 hour, and a fourth group (n = 17 animals) received saline solution. All animals were assessed at 48 hours for hind limb motor function (Tarlov scale, 0-5). RESULTS: Animals that received ATL-146e for 3 hours (Tarlov score, 4.3 +/- 0.22; P <.001) or 1.5 hours (Tarlov score, 2.7 +/- 0.6; P <.05) had improved neurologic outcomes compared with rabbits that received saline solution (Tarlov score, 0.6 +/- 0.29). Animals that received ATL-146e for 1 hour (Tarlov score, 0.7 +/- 0.8) were not significantly different from those animals that received saline solution. CONCLUSIONS: Systemic ATL-146e, given during reperfusion, results in time-dependent improvement in spinal cord function after ischemia. This implies that the mechanism of spinal reperfusion injury includes leukocyte-mediated inflammation at a critical post-ischemic time interval.

A technique for adequate coverage of the proximal suture line during abdominal aortic aneurysm repair.

The proximal suture line is a vulnerable area after abdominal aortic aneurysm repairs. This area has been implicated in various postoperative complications, such as pseudoaneurysm formation, graft-enteric fistula, and suture line disruption. We present a technique that provides safe and adequate coverage of this suture line by using the aneurysm sac. This technique is derived from the z-plasty technique used for scar revision. The technique is illustrated with detailed line drawings. None of the patients in whom we used this technique have had any complications related to the proximal suture line.