Colin J. Hilton

Vascular complications of lung transplantation

BACKGROUND The data on vascular anastomotic complications after single-lung and bilateral lung transplantation are scant. METHODS We reviewed the data on our patients having single and bilateral lung transplantation to examine our experience and management of vascular anastomotic complications. RESULTS We retrospectively identified 5 of 109 consecutive patients undergoing lung transplantation who had postoperative pulmonary arterial or venous obstruction. There were 4 women and 1 man (age range, 32 to 53 years). Three patients had left single-lung transplantation, 1 patient had right single-lung transplantation, and 1 patient underwent bilateral sequential lung transplantation. Complications comprised two right-sided and two left-sided pulmonary artery stenoses and one combined left pulmonary arterial and venous obstruction. Isotope perfusion scanning was used in 3 patients and suggested a vascular stenosis in all of them. Pulmonary angiography was used in each as a confirmatory test and to demonstrate anatomic details. Transesophageal echocardiography was used in 1 patient and did not detect a right pulmonary artery stenosis. One patient underwent revision of a pulmonary artery stenosis with a period of warm ischemia and subsequent fatal lung injury. Two revisions were undertaken on cardiopulmonary bypass with a cold blood flush to the transplanted lung. One venous anastomotic angioplasty with stent insertion was performed. Two patients died before treatment. All 5 patients died between 5 and 630 days postoperatively. CONCLUSIONS Vascular complications carry a high mortality. Reoperation, preferably using cardiopulmonary bypass and a cold blood flush technique to avoid further lung injury, is recommended. In high-risk patients, dilation or stent insertion can be considered.

Upper gastrointestinal dysmotility in heart-lung transplant recipients

Recipient pneumonectomy and the necessity for meticulous hemostasis in heart-lung transplantation can result in injury to the vagus nerves as they course through the posterior mediastinum, with consequent delay in gastric emptying. This has been reported to lead to chronic aspiration and associated pulmonary sequelae. To study the association between delayed gastric emptying, bronchiectasis, and bronchiolitis obliterans after heart-lung transplantation, we performed esophageal manometry, 24-hour pH monitoring, and radioisotopic gastric emptying in 10 patients who underwent heart-lung transplantation. Three patients had grossly delayed liquid and solid emptying that was compatible with complete vagotomy. Six other patients had delayed liquid but normal solid emptying--an unexplained finding that is the reverse of what one would expect from vagal injury. Two of these 9 patients had esophageal dysmotility, but none demonstrated gastroesophageal reflux. One remaining patient had faster than normal gastric emptying for both solids and liquids. Of the 10, 2 patients have radiologic changes of bronchiectasis and 3 have biopsy evidence of obliterative bronchiolitis. There is no relationship between these sequelae and the occurrence of esophageal dysmotility, gastroesophageal reflux, or vagotomy. We conclude that gastric emptying abnormalities can occur after heart-lung transplantation, but such abnormalities are not associated with gastroesophageal reflux and the development of pulmonary sequelae, as previously reported.

Orthotopic cardiac transplantation for the failing Fontan circulation.

OBJECTIVE Modified Fontan procedures are now employed in several conditions unsuitable for bi-ventricular repair. Selection criteria have been relaxed. The procedure is palliative. Longterm outlook is unknown. This study evaluated factors associated with the development of a failing Fontan circulation and transplantation results. METHODS Retrospective review of patients referred to a single centre for cardiac transplant assessment. RESULTS Between 1985 and 1996, 46 of 448 cardiac transplants were performed for congenital heart disease. Nine of these were performed in patients with a failing Fontan circulation (four adults, five children). In six cases, the dominant ventricle had left ventricular (LV) morphology. Congenital anomalies included double outlet right ventricle (three cases), double inlet left ventricle (two cases), tricuspid atresia (two cases), and pulmonary atresia with intact ventricular septum (one case). Fontan procedures were performed in absence of sinus rhythm (four cases), atrio-ventricular (AV) valve regurgitation (two cases), aortic regurgitation and systolic LV dysfunction (one case), elevated mean pulmonary artery pressure (one case), and older age (>7 years, eight cases). Three patients required early re-operation and two needed permanent pacing. Subsequent deterioration associated with loss of sinus rhythm (four cases) and progressive AV valve regurgitation (seven cases) led to transplant assessment (at < 1 year, five cases; at 2-12 years, four cases). All patients were listed for transplantation. Three patients required intravenous inotropic support and three patients with lymphocytotoxic antibodies needed prospective crossmatching. Donor cardiectomy was modified to facilitate implantation. The recipient operation involved pulmonary artery reconstruction (using pericardium), modified atrial and direct caval anastomoses. Three patients died within 24 h of surgery (two graft failures, one haemorrhage). In operative survivors (n = 6), intensive care stay was 3-16 days, and hospital stay ranged from 14 to 32 days. There have been no subsequent deaths (follow up, 0.5-4.7 years). CONCLUSION In high-risk Fontan candidates, transplantation may be preferable at the outset. Previous surgery, lymphocytotoxic antibodies, indeterminate pulmonary vascular resistance, emergency status, sub-optimal donor selection, and perioperative bleeding contribute to peri-operative mortality. In survivors, the outcome remains very encouraging.

Outcome of Toxoplasma gondii mismatches in heart transplant recipients over a period of 8 years

Donor-related infection due to Toxoplasma gondii is a well-recorded complication of cardiac transplantation. In order to assess the efficacy of co-trimoxazole in small doses as prophylaxis for primary Toxoplasma gondii infection in seronegative heart and heart-lung transplant recipients receiving organs from seropositive donors, we reviewed the serostatus and clinical outcome of all such mismatched transplants performed at our unit over a period of 8 years. Of 310 transplants performed between May 1985 and May 1993, donor and recipient serum samples were available for 257 heart and 33 heart-lung transplants. Of these, 13 (4.5%) were toxoplasma mismatches. Post-transplant review serum samples were available for 3 months or longer for nine of the 13 mismatches. The first three patients received co-trimoxazole 480 mg bd orally for 3 months (regimen A) while the remainder received only the standard prophylaxis designed for Pneumocystis carinii i.e., 960 mg bd orally three times per week for 3 months (regimen B). Seroconversion was demonstrated in only one patient (regimen A). Furthermore, none of the mismatched patients developed serious infection compatible with primary toxoplasmosis. We therefore conclude that in centres with a low prevalence of toxoplasma seropositivity, testing of donor and recipient serum for Toxoplasma gondii antibody should be performed only when clinically indicated and, in addition, standard prophylaxis for Pneumocystis carinii may be adequate for preventing primary toxoplasmosis.

Healing of the bronchus in pulmonary transplantation

OBJECTIVE To review the results of bronchial healing in a consecutive series of 100 isolated pulmonary transplants, performed at one centre between 1987 and 1994. METHODS A retrospective review of 123 assessable bronchi (61 in single lung and 62 in bilateral lung) transplants was carried out. All anastomoses were assessed by bronchoscopy at 7-10 days, and follow up was from one to seven years. The effect on bronchial dehiscence or stenosis requiring endobronchial stent, of suture technique, pre and post operative steroid administration, bronchial wrap, donor ischaemic time and time to first rejection episode was assessed. RESULTS Complications of airways healing occurred in four patients: stenosis in two and dehiscence in two (1.6% of bronchi at risk in both groups). Airway complication was not affected by steroids, pre-operative diagnosis, presence of a wrap (34 with pericardium or omentum, 89 with peribronchial tissue alone) or any other variable. There was a higher incidence of dehiscence (2/36) with continuous rather then interrupted (0/87) suture, but this was not statistically significant. There was one airway-related death. Two patients who required anastomotic stenting remain alive and well. CONCLUSIONS A very low complication rate can be achieved without recourse to bronchial wrapping, telescoping anastomoses or steroid avoidance. Combined heart-lung transplantation or bronchial revascularisation are not required to achieve reliable bronchial healing.

Perfadex for clinical lung procurement: is it an advance?

BACKGROUND Extensive laboratory experience suggested that low potassium dextran lung preservation solution (Perfadex; Medisan, Uppsala, Sweden) is superior to Euro-Collins (EC; Frusen, Hamburg, Germany), the clinical standard. The purpose of this study was to evaluate Perfadex in clinical lung transplantation. METHODS A retrospective analysis of the outcome of 69 consecutive lung allografts retrieved and used for transplantation was made. Donor lungs were flushed with EC in 37 patients and Perfadex in 32 patients. The evaluation measurements were quantitative chest roentgenogram score (grade 0 to 4), graft oxygenation, duration of mechanical ventilation, length of intensive care treatment, and survival. RESULTS The mean chest roentgenogram score was 1.55 and 1.81 for the EC group compared with 1.18 and 2.09 for the Perfadex group at 1 and 48 hours, respectively (p = 0.1 and 0.8, respectively). Arterial alveolar oxygen tension ratio was similar at 12 and 24 hours (0.61 vs 0.67; p = 0.8; and 0.64 vs 0.53; p = 0.3, respectively). The mean ventilation time was 71.2 +/- 32.3 hours versus 81.9 +/- 43.6 hours for the EC and Perfadex groups, respectively (p = 0.4). The mean intensive therapy unit stay was 3.1 +/- 2.6 days for the EC group compared with 4.1 +/- 3.9 days for the Perfadex group (p = 0.4). Death caused by primary organ failure was 5.1% for the EC group compared with 3.1% for the Perfadex group (p = 0.8). CONCLUSIONS There was no difference between Perfadex and EC in clinical lung preservation. This may reflect the difference between controlled laboratory environment and the real world of brain death lung injury. Further studies are required to investigate the impact of Perfadex in the long-term outcome of lung transplantation.

Mediastinitis in heart and lung transplantation: 15 years experience

BACKGROUND Mediastinitis after sternotomy carries a very high mortality, especially in patients receiving immunosuppressive treatment. METHODS A retrospective analysis of the data for patients who had undergone cardiopulmonary transplantation between May 1985 and December 2000 was undertaken. A total of 776 patients had either a median sternotomy or a transverse sternotomy through a clam-shell incision. Transplantations were as follows: 591 heart (3 simultaneous heart and renal, and 1 heart and liver), 126 bilateral sequential lung, 57 heart-lung, 1 en bloc double-lung, and 1 heart and single-lung. RESULTS In all, 21 (2.7%) recipients had mediastinitis. Of these, 14 had heart, 3 heart-lung, and 4 bilateral lung transplantation. There were 18 median and 3 transverse sternotomies. There were 6 deaths (28.6%). Treatment consisted of antibiotics alone in 2 patients and subxiphisternal drainage in another 2 patients. The sternum was reopened in 17 (80.95%) patients, with debridement and primary closure alone in 5 of these 17 patients and additional irrigation in the other 12. Those who had resternotomy, debridement, and substernal irrigation had a better outcome when compared with the outcomes of other modes of treatment (1 death among 12 patients) (p = 0.06). Age, cardiopulmonary bypass time, body mass index, time to diagnosis, and treatment did not differ between those who survived and those who did not. CONCLUSIONS Early aggressive debridement with substernal irrigation is the best mode of treatment for patients with posttransplantation mediastinitis.

Airway complications after pulmonary transplantation

Airway healing was identified initially as one of the fundamental limitations of pulmonary transplantation. Recent experience suggests that this is no longer the case. A series of 67 pulmonary transplants (27 heart-lung, 31 single-lung, 9 double-lung) in 66 patients surviving more than 14 days was reviewed with reference to airway complications. There were 75 anastomoses at risk in two groups as defined by anastomotic location: 47 anastomoses in 38 patients in a bronchial group and 28 anastomoses in 28 patients in a tracheal group. A total of 10 airway complications developed (stenosis in 5 patients [4 bronchial group, 1 tracheal group] and dehiscence in 5 patients [1 bronchial group, 4 tracheal group]) causing two airway-related deaths (2 of 67) in the series. However, no significant correlation could be identified with either ischemic interval, suture technique, type of wrap, preoperative or postoperative steroid therapy, or date of first rejection episode. Airway complications are no longer a major limitation of pulmonary transplantation. Satisfactory airway healing can occur in both the presence of steroid therapy and the absence of an omental or pericardial wrap.

Surgery for ventricular tachycardia associated with right ventricular dysplasia: disarticulation of right ventricle in 9 of 10 cases.

Ten patients (nine men, one woman; mean age 39 years) with arrhythmogenic right ventricular dysplasia underwent surgery to control life-threatening drug refractory ventricular arrhythmias. All had ventricular tachycardia causing syncope and six had a history of cardiac arrest. In all a minimum of three antiarrhythmic drugs (mean five) had been ineffective. At operation, the right ventricle was grossly diseased in all patients. Ventricular tachycardias were induced and mapped intraoperatively in all patients. The surgical plan was to ablate the arrhythmogenic focus if it was less than 4 cm2; one patient was so managed. Of the remaining nine, four underwent partial (approximately 40% of the right ventricular free wall) and five underwent total right ventricular disarticulation. All survived the operation and are alive at a mean follow-up interval of 24 months (range 5 to 67). Two patients developed new sustained ventricular tachycardias. These were well tolerated and, unlike the original arrhythmias, were easily controlled by drug treatment. All patients who underwent right ventricular disarticulation manifested signs of right heart failure in the early postoperative period, but these lessened progressively with the development of systolic septal movement into the right ventricular cavity. All 10 patients are in New York Heart Association class I or II at last review. In selected patients with arrhythmogenic right ventricular dysplasia, surgery offers a curative treatment for ventricular tachycardia and should be considered for patients whose arrhythmias are life-threatening and refractory to drug treatment.

Orthotopic heart transplantation for congenital heart disease. Technical considerations.

Heart transplantation for congenital heart disease poses unique problems because of structural anomalies and previous corrective and palliative surgery. In the period between May 1985 and February 1992 a total of 231 orthotopic heart transplants were performed at our hospital -22 of these procedures were carried out in patients with congenital heart disease. The patients ages ranged from 1 month to 51 years (median 10 years). There were 13 patients in the paediatric group (under 16 years) and 9 patients in the adult group (16 years or older). The diagnoses included univentricular connections (8 patients), complex morphology (4 patients), congenitally corrected transposition of the great arteries (TGA) (3 patients), hypoplastic left heart syndrome (2 patients), Fallots tetralogy, tricuspid atresia, TGA, pulmonary atresia with intact ventricular septum and atrial septal defect (ASD) and ventricular septal defect (VSD). These patients had protected pulmonary circulation due to previous surgery or as a result of intrinsic pulmonary stenosis. Seventeen patients (77%) had undergone 29 prior operations (21 palliative and 8 corrective) including Blalock-Taussig shunts, pulmonary artery (PA) banding, ASD and VSD repair, Fontan procedure and Mustard operation. There were 2 early deaths in the paediatric group and 4 early deaths in the adult group, but no late deaths. The cause of death was multi-organ failure following uncontrollable haemorrhage in 3 patients, sepsis in 1 patient and donor organ failure in the 2 paediatric patients. Specific surgical manoeuvres were required to create the normal anatomical configuration. These included the rerouting of venous circulation, pulmonary artery reconstruction and atrial septation. Adequate donor tissue was taken to permit satisfactory reconstruction.(ABSTRACT TRUNCATED AT 250 WORDS)