David N. Hopkinson

A prospective randomised comparison of cardiotomy suction and cell saver for recycling shed blood during cardiac surgery

OBJECTIVE Post-operative neuropsychological complications correlate with intra-operative microemboli in the middle cerebral artery. When severe neurological complications follow cardiac surgery, diffuse cerebral fat emboli are present at autopsy. Recycling shed blood with cardiotomy suction is an important source of cerebral fat microemboli. A cell saver may reduce this. METHODS Twenty patients were prospectively randomised to assess the amount of fat in blood salvaged from the pericardium and returned to the patient with either cell saver or cardiotomy suction. Blood samples were taken before and after filtration in the cardiotomy suction group or cell saver processing in the cell saver group. After centrifuging samples, fat content was graded on a scale of 0-3 by a blinded independent observer. Fat content was also quantified by weight. RESULTS Compared with cardiotomy suction, cell saver removed significantly more fat from shed blood. Median fat grading after cell saver was 0 (0-1) compared with 1 (1-2) for cardiotomy suction (P=0.0001). Percentage reduction in fat weight achieved by cell saver or cardiotomy suction was 87% compared to 45% (P=0.007). There was no difference in the post-operative use of blood or blood products, haemoglobin, or bleeding between the two groups. CONCLUSION Use of cell saver results in less fat being recycled during cardiopulmonary bypass.

Pneumonectomy for stage I (T1N0 and T2N0) nonsmall cell lung cancer has potent, adverse impact on survival

BACKGROUND Surgically treated, stage I (T1N0 and T2N0) nonsmall cell lung cancer has a relatively favorable prognosis. Our aim was to determine whether performing a pneumonectomy in this group of patients has an impact on survival. METHODS Four hundred eighty-five patients with stage I nonsmall cell lung cancer undergoing lung resection between 1991 and 2000 were studied. Three hundred seventy-four patients underwent a smaller resection than a pneumonectomy and 111 had a pneumonectomy. RESULTS Patients undergoing less extensive resections were older (mean age, 65 vs 63 years) (p = 0.01); these patients were also more likely to have a history of chronic obstructive airway disease (9% vs 2%) (p = 0.01) or asthma (10% vs 3%) (p = 0.04), nonsquamous cell type (56% vs 27%) (p < 0.0001), and T1 tumor stage (66% vs 17%) (p = 0.002) than patients having a pneumonectomy. Operative mortality was 2.4% versus 8% (p = 0.01). Overall 1-, 3-, and 5-year Kaplan-Meier survival rates (95% confidence interval [CI]) after less extensive resections were 85% (CI, 82% to 90%), 63% (CI, 56% to 69%), and 50% (CI, 42% to 57%), respectively, and after pneumonectomy the survival rates were 66% (CI, 53% to 73%), 47% (CI, 35% to 57%), and 44% (CI, 32% to 55%), respectively (p = 0.0006). When the Cox proportional hazards model was applied to all study patients (n = 485), pneumonectomy (p = 0.001), T2 stage (p = 0.006), older age (p = 0.03), and male gender (p = 0.03) were independent adverse predictors of survival. When the analysis was limited to the patients having T1N0 disease (n = 145), pneumonectomy (p = 0.0008), older age (p = 0.05), and nonsquamous cell type (p = 0.02) were independent adverse determinants of survival. When only the patients with T2N0 disease were analyzed (n = 340), male gender (p = 0.0005) and pneumonectomy (p = 0.01) were independent negative predictors of survival. CONCLUSIONS In this study, the patients who underwent pneumonectomy for stage T1N0 or T2N0 nonsmall cell lung cancer had a significantly poorer survival than those patients who underwent smaller lung resections.

Critical importance of the first 10 minutes of lung graft reperfusion after hypothermic storage

BACKGROUND We have shown previously that lung graft function can be improved by achieving reperfusion with stepwise increments of perfusion pressure over 60 minutes. This study aimed to establish whether similar benefit could be achieved with a shorter, simpler protocol and different storage conditions. METHODS Rat lungs were flushed with University of Wisconsin or modified Euro-Collins solution and reperfused for 1 hour with blood from a support animal. Grafts were reperfused immediately or after storage at 4 degrees C for 24 hours (University of Wisconsin solution) or 6 hours (Euro-Collins solution). Stored-graft reperfusion was initiated with a 0-, 5-, or 10-minute period during which reperfusion pressure was reduced by 50%. RESULTS Stored grafts receiving 0 to 5 minutes of initial low-pressure reperfusion performed poorly, with reduced oxygenation and blood flow and elevated pulmonary artery pressure, airway pressure, and wet/dry weight ratio. In contrast, 10 minutes of initial 50%-pressure reperfusion yielded function comparable with that in controls with both storage conditions. CONCLUSIONS An initial 10-minute period of 50%-pressure reperfusion improves the function of stored rat lung grafts, whereas 5 minutes is insufficient.

Controlled Reperfusion Protects Lung Grafts During a Transient Early Increase in Permeability

BACKGROUND We have previously shown that an initial 10-minute period of low-pressure reperfusion prevents the lung graft dysfunction that follows physiologic-pressure reperfusion. Possible mechanisms were investigated in this study. METHODS Rat lungs were reperfused ex vivo using a parabiotic animal after 0-hour (groups A through C) or 24-hour (groups D through G) storage. Reperfusion pressure was either physiologic (groups A through D) or reduced by 50% for a specified time (groups E through G). The duration of reperfusion was 5 minutes (groups A, D, and E), 10 minutes (groups B and F), or 30 minutes (groups C and G), at which time endothelial permeability was measured through iodine 125-labeled albumin leakage and neutrophil sequestration through tissue myeloperoxidase activity. RESULTS Graft function in group D deteriorated rapidly, whereas groups E through G performed at control levels. Albumin leakage was significantly elevated in group D; with controlled reperfusion, it was elevated after 5 minutes (group E) but had returned to baseline at 10 minutes (group F) and 30 minutes (group G). Myeloperoxidase levels were not significantly different between groups. CONCLUSIONS Endothelial permeability is transiently elevated in the early phase of lung graft reperfusion. Initial low-pressure reperfusion may be protective by preventing irreversible edema formation during this period.

Low-Dose Nitric Oxide Inhalation During Initial Reperfusion Enhances Rat Lung Graft Function

BACKGROUND In ischemia-reperfusion injury, the production of nitric oxide by dysfunctional endothelium falls rapidly within minutes of the onset of reperfusion. Replenishment during this critical early period using inhaled nitric oxide may benefit lung grafts through modulation of vascular tone, endothelial permeability, neutrophil and platelet function, and availability of reactive oxygen species. METHODS Rat lung grafts were flushed with 60 mL/kg cold University of Wisconsin solution and were reperfused either immediately (group I, n = 5) or after 24-hour 4 degrees C storage (groups II and III, n = 5 each), for 60 minutes in an ex vivo model incorporating a support animal. Graft ventilation was with room air. In group III, 20 parts per million inhaled nitric oxide was added during the initial 10 minutes of reperfusion, whereas in groups I and II, equivalent flows of nitrogen were added to standardize oxygen concentration. RESULTS Compared with group I, graft function in group II was poor, with reductions in oxygenation and blood flow and elevations of mean pulmonary artery pressure, peak airway pressure, and wet to dry weight ratio. In contrast, during nitric oxide inhalation in group III, graft function improved to control levels. This improvement was subsequently sustained throughout the reperfusion period. CONCLUSIONS Low-dose inhaled nitric oxide administration in the early phase of reperfusion of stored lung grafts can yield sustained improvement in function. There may be a role for inhaled nitric oxide in the prevention of reperfusion injury in transplanted lungs.

Attenuation of lung graft reperfusion injury by a nitric oxide donor

OBJECTIVE One of the primary features of ischemia-reperfusion injury is reduced production of protective autocoids, such as nitric oxide, by dysfunctional endothelium. Administration of a nitric oxide donor during reperfusion of lung grafts may therefore be beneficial through modulation of vascular tone and leukocyte and platelet function. METHODS Rat lung grafts were flushed with University of Wisconsin solution and reperfused for 1 hour in an ex vivo model incorporating a support animal. Group I grafts (n = 6) were reperfused immediately after explantation, group II (n = 6) and III (n = 5) grafts after 24 hours of storage at 4 degrees C. In group III, glyceryl trinitrate, a nitric oxide donor, was administered during the first 10 minutes of reperfusion at a rate of 200 micrograms/min. In an additional group (n = 5), 200 micrograms/min hydralazine was administered instead, to assess the effect of vasodilation alone. RESULTS Graft function in group II deteriorated compared with that in group I, with significant reduction of graft effluent oxygen tension and blood flow and elevation of pulmonary artery pressure, peak airway pressure, and wet/dry weight ratio. In contrast, in group III, glyceryl trinitrate treatment improved graft function to baseline levels in all these parameters. Administration of hydralazine, meanwhile, produced mixed results with only two out of five grafts functioning at control levels. CONCLUSIONS In this model, administration of glyceryl trinitrate to supplement the nitric oxide pathway in the early phase of reperfusion has a sustained beneficial effect on lung graft function after 24-hour hypothermic storage, probably through mechanisms beyond vasodilation alone.

Relative importance of prostaglandin/cyclic adenosine monophosphate and nitric oxide/cyclic guanosine monophosphate pathways in lung preservation

BACKGROUND Modulation of vascular tone and platelet and neutrophil function through the prostaglandin/cyclic adenosine monophosphate or nitric oxide/cyclic guanosine monophosphate pathway can benefit lung graft function. The relative importance of these pathways is unclear. METHODS Rat lung grafts (5 per group) were studied in an ex vivo reperfusion model. Group I grafts were pretreated with prostacyclin (20 ng.kg-1.min-1), flushed with cold Euro-Collins solution containing prostacyclin (200 micrograms/L), and reperfused immediately for 1 hour. Group II grafts were similarly procured but were stored at 4 degrees C for 6 hours before reperfusion. In group III, no prostacyclin therapy was used; instead, the nitric oxide donor glyceryl trinitrate (0.1 mg/mL) was added to the flush/storage solution, and the grafts were stored for 6 hours. RESULTS Group II grafts performed poorly compared with those in group I, with substantial deterioration of oxygenation and blood flow and elevation of pulmonary artery pressure, peak airway pressure, and wet to dry weight ratio. In contrast, graft function in group III was similar to that in controls. CONCLUSIONS Lung graft integrity after storage in Euro-Collins solution was better preserved by glyceryl trinitrate than by prostacyclin in this model.

Pulmonary adenocarcinoma is associated with poor long-term survival after surgical resection: Effect of allogeneic blood transfusion

The significance of allogeneic blood transfusion in the prognosis of patients with nonsmall lung carcinoma (NSCLC) remains controversial. Reports have suggested that patients with adenocarcinoma have a worse prognosis from cancer than patients with squamous cell carcinoma (SCC), but this evidence is lacking in NSCLC. The objective of the current study was to elucidate the correlation between perioperative allogeneic blood transfusion and the prognosis in patients with adenocarcinoma and SCC.

Giant pleural fibroma with an abdominal vascular supply mimicking a pulmonary sequestration

A 37 -year-old woman was found to have a giant mass in her right chest with an abnormal abdominal vascular supply at preoperative workup. Suspecting a pulmonary sequestration, the lesion was embolized and then removed through a standard thoracotomy. A broad-based, vascularized pedicle connected the mass to the diaphragm. Final pathology demonstrated a solitary fibrous tumor of the pleura with no malignant features. We believe this is the first case of solitary fibrous tumor of the pleura with a direct vascular supply from the abdominal aorta at the level of the renal arteries reported in the literature.

Atrial Myxomas: A Single Unit's Experience in the Modern Era

Background: Although an atrial myxoma is the commonest cardiac tumor, it is still relatively rare, with an annual incidence of approximately 0.5 per million. In our unit, which performs 1000 major cardiac procedures per year, this equates to approximately 3 patients annually. We therefore sought to evaluate our experience of managing this type of tumor over the last 5 years. Methods: A retrospective review was performed of prospectively collected data from the departmental database. We analyzed consecutive patients who were operated upon between 2002 and 2007. Three patients with a papillary fibroelastoma on histological examination were excluded from this study. Results: We have performed excision of atrial myxoma in 18 patients. Twelve patients (66%) were female; the median age was 64 years (range, 35-80 years), and the median logistic euroSCORE was 5.22% (range, 1.51-27.82%). Fifteen patients (83%) were deemed urgent, 2 elective, and 1 emergency. Sixteen tumors (89%) were left sided. Symptoms attributable to the tumor were found in 16 of the 18 patients (embolic, n = 9; chest pain, n = 3; palpitations, n = 2; incidental finding, n = 2, others n = 4), and the mean time from diagnosis to operation was 3 days (range, 0-22 months). The median cardiopulmonary bypass time was 87 minutes (range, 28-228 minutes), with the median aortic cross clamp time being 61 minutes (16-175 minutes). The approaches used were transeptal via right atriotomy (n = 8), biatrial/Dubost (n = 4), left atrial (n = 4), and right atrial (n = 2); the interatrial septum was involved in 14 patients. The resultant defect was closed using a pericardial (n = 8) or prosthetic patch (n = 5) or directly sutured (n = 5). Concomitant procedures were performed in 8 patients (coronary artery bypass graft [CABG], n = 4; mitral valve replacement [MVR], n = 2; valve + grafts, n = 2). All tumors were completely excised. Postoperatively there were no deaths within 30 days of the procedure. Indeed, only 2 patients have died at 4 and 25 months postoperatively, respectively, both of unrelated causes. Median intensive therapy unit (ITU) stay was 2 days (range, 1-9 days), and median hospital stay was 10 days (range, 5-20 days). A permanent pacemaker was required in only 1 patient, and median blood loss was 340 mL (range, 140-1760 mL). Atrial fibrillation was the commonest complication affecting 6/18 patients (33%). Conclusions: Excision of atrial myxoma can be performed using a variety of intraoperative approaches and closure techniques, all with acceptable postoperative morbidity and low mortality rates. To date, no recurrences have been found at median 2-year follow-up.