Wilfried Wisser

Pulmonary Retransplantation: Is it Worth the Effort? A Long-term Analysis of 46 Cases

BACKGROUNDnPulmonary retransplantation remains the only therapeutic option in some cases of severe primary graft dysfunction (PGD), advanced bronchiolitis obliterans syndrome (BOS), and in some cases of severe airway problems (AWP), mainly cicatriceal stenosis. However, its value has been questioned due to the overall scarcity of donor organs and reports indicating unsatisfactory outcome. We analyzed our institutional experience with pulmonary retransplantation to evaluate its value for different indications.nnnMETHODSnWe retrospectively analyzed all 46 patients undergoing pulmonary retransplantation from the 567 consecutive primary lung or heart-lung transplantations performed in our department from August 1995 to August 2006. We stratified patients according to indication for retransplantation and analyzed the outcome.nnnRESULTSnForty-six patients (mean age 41 +/- 16 years, 18 men and 28 women) underwent pulmonary retransplantation (14 bilateral lung transplantations, 32 single-lung transplantations) for primary graft dysfunction (n = 23), bronchiolitis obliterans syndrome (n = 19) and airway problems (n = 4). Mean time to retransplantation was 26 +/- 27 days in the PGD group, 1,069 +/- 757 days in the BOS group and 220 +/- 321 days in the AWP group. Thirty-day, 1-year and 5-year survival rates after retransplantation were 52.2%, 34.8% and 29.0% in the PGD group and 89.2%, 72.5% and 61.3% in the BOS group, respectively. All 4 patients in the AWP group are presently alive (BOS vs PGD: p = 0.02; BOS vs AWP: p = 0.27; PGD vs AWP: p = 0.06).nnnCONCLUSIONSnPulmonary retransplantation for bronchiolitis obliterans offers long-term survival rates in the range of primary lung transplantation for selected patients. Long-term survival rates for retransplantation due to PGD are significantly lower, warranting restrictive use in this setting. In our experience with a limited number of patients, retransplantation for airway problems has shown excellent results. Pulmonary retransplantation for chronic problems is a plausible approach, provided that patients are carefully selected. Retransplantation for PGD should be avoided.

Interventional Lung Assist: A New Concept of Protective Ventilation in Bridge to Lung Transplantation

On March 22, 2006, the first Interventional Lung Assist (ILA) Consensus Meeting was held in Hannover, Germany, hosted by the Hannover Thoracic Transplant and Cardiac Assist Program at the Hannover Medical School. Leading experts in the field of lung transplantation, respiratory and critical care medicine, lung injury, mechanical ventilation, extracorporeal life support, and oxygenator engineering were formally invited to participate. The main goal was to translate previous clinical experience with the ILA into a consensus for the use of the ILA as a bridge to lung transplantation.

Extended videoscopic robotic thymectomy with the da Vinci telemanipulator for the treatment of myasthenia gravis: the Vienna experience.

Surgical treatment of myasthenia gravis should include the complete resection of the thymus with the whole fatty tissue adherent to the pericardium for immunologic as well as oncologic reasons. The aim of the current study was to investigate the efficacy and safety of robotic approach. A total of 18 patients with myasthenia gravis (mean age 44 years) have been operated robotically via a left-sided approach. Preoperative MGFA (Myasthenia Gravis Foundation of America) classification was: Class I n=4, Class IIa n=4, Class IIb n=5, and Class IIIa n=3, IIIb n=2. Total endoscopic resection was feasible in 17/18 patients. One patient had to be converted due to bleeding. In the remaining patients, operative time was 175 min, intensive care unit (ICU) one day, hospital stay four days. In all patients it was possible to perform an extended thymic resection. MGFA post-intervention status after a mean of 18 months follow-up showed complete stable remission n=5, pharmacologic remission n=4, minimal manifestations n=5, unchanged n=1. Complete endoscopic thymus surgery with the da Vinci surgical system enables a complete and extended resection of all thymic tissue in the mediastinum. Due to the minimal trauma, patients can return to full activity within a short time.

Management of open chest and delayed sternal closure with the vacuum assisted closure system: preliminary experience

The management of open chest with the vacuum assisted closure (VAC) system was evaluated in terms of impact on cardiac hemodynamics, respiratory parameters, complications, incidence of wound infection, overall handling and outcome in 22 patients during 2005 and 2008 after cardiac surgery. The decision to leave the sternum open was made electively in all patients at the time of primary operation or reexploration. In four patients the VAC was implanted during the primary operation. In the remainder the VAC was implanted after a mean of five days after the primary operation. The overall mortality rate was 45% (10/22). None of the patients developed a sternal wound infection, nor were there any VAC related complications. Management of open chest with the VAC system can be considered as an alternative to sterile draping. The VAC has no negative impact on cardiac hemodynamics as well as respiratory mechanics. The feared complication of right ventricular rupture and massive bleeding can be effectively prevented. Through the stabilizing of the thoracic cage, the patient can be easily moved and mobilized for nursing reasons and pneumonia prevention. Furthermore, the VAC effectively prevents the contamination of the wound and the mediastinum with potential subsequent infection.

The impact of perioperative atelectasis on antibiotic penetration into lung tissue: an in vivo microdialysis study

ObjectivePostoperative pneumonia is a potentially devastating complication associated with high mortality in intensive care unit (ICU)-patients. One of the major predisposing factors is the perioperative occurrence of atelectatic formations in non-dependent lung areas. Perioperative ventilation/perfusion mismatch due to atelectasis may influence antibiotic distribution to lung tissue, hence increasing the risk of postoperative pneumonia. We evaluated whether differences in ventilation/perfusion mismatch can influence antibiotic distribution into lung tissue by means of in vivo microdialysis, comparing patients undergoing coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB) (atelectasis model), with patients operated with the off-pump coronary artery bypass grafting (OPCAB)-technique.Patients and methodsWe compared five patients operated with CPB (CPB-group) and five patients undergoing CABG with OPCAB-technique (OPCAB-group). Levofloxacin (500xa0mg) was administered intravenously, after surgery, in the ICU. Time versus concentration profiles of levofloxacin in lung tissue and plasma were measured at regular time-intervals.ResultsIn the OPCAB-group, the median of the maximum concentration of levofloxacin in lung tissue (4.1xa0μgxa0ml−1xa0±xa07, range 3.7–11.8xa0μgxa0ml−1) was significantly higher compared with the CPB-group (2.5xa0μgxa0ml−1xa0±xa00.3, range 2.0–2.9xa0μgxa0ml−1) (Pxa0=xa00.046). Median levofloxacin tissue/plasma area under the concentration curve (AUC) ratio in lung tissue was 0.3xa0±xa00.2 (range 0.1–0.7) in the CPB-group versus 0.7xa0±xa01.6 (range 0.4–0.8) in the OPCAB-group (Pxa0=xa00.015).ConclusionsData indicate that postoperative interstitial antibiotic concentration is influenced by perioperative atelectasis formation. Our findings suggest the re-evaluation of clinical dosing schemas of antibiotic therapy in a variety of diseases associated with atelectasis formation.

Functional improvements in ventilatory mechanics after lung volume reduction surgery for homogeneous emphysema

OBJECTIVEnBetween September 1994 and August 1996 Lung Volume Reduction Surgery (LVRS) was performed through median sternotomy, videoendoscopically or by thoracotomy in 54 consecutive patients (age 34-69 years, mean 48 years).nnnMETHODSnThe areas with the most destroyed lung parenchyma were resected by means of linear stapling devices. A total of 5 patients died postoperatively due to aspiration pneumonia, multiorgan failure and acute hepatic failure respectively. A marked functional improvement and increase in quality of life was observed in the remaining patients.nnnRESULTSnResidual volume decreased from 317.0 +/- 12.4% of predicted (%p) preoperatively to 226.2 +/- 8.8%p within the first month (P = 0.0001). FeV1 significantly increased from 23.7 +/- 1.3%p preoperatively to 36.3 +/- 4.1%p during the first 6 months postoperatively (P = 0.0016). Radiological signs of hyperinflation and distention of the thorax preoperatively improved to a more dome shaped diaphragm and narrowed intercostal spaces. These morphologic changes resulted in better ventilatory muscle function. The intrinsic PEEP significantly decreased from 5.92 +/- 0.64 cm H2O preoperatively to 1.70 +/- 0.25 cm H2O postoperatively (P = 0.0001). The work of breathing decreased from 1.58 +/- 0.09 J/l preoperatively to 0.99 +/- 0.07 J/l postoperatively (P = 0.0001).nnnCONCLUSIONSnIn conclusion, LVRS is an excellent therapeutic option for patients with homogeneous emphysema with additional signs of severe hyperinflation.

Incidence and outcome of major non-pulmonary surgical procedures in lung transplant recipients

OBJECTIVEnPulmonary transplant recipients are at high risk from various conditions requiring surgical intervention. As little is known about their exact incidence and course, we examined such procedures in detail.nnnMETHODS AND PATIENTSnWe have retrospectively analyzed major nonpulmonary surgical procedures performed in 124 consecutive patients who received an isolated lung transplant at the University of Vienna between 1989 and December 1995. Twenty-two patients underwent a total of 28 major interventions (22/124 = 17.7%), resulting in an incidence of one procedure every 5.8 patient years of follow-up. The mean interval between transplantation and intervention was 17.9 months (range 3 days to 62 months) with six interventions being carried out during the first month after transplantation. Fourteen emergency operations were performed, the remaining 14 procedures were carried out electively. Overall, 15 abdominal procedures, four thoracic, four orthopedic, two gynecological, one neurosurgical, one urological and one plastic surgery were performed.nnnRESULTSnThere was no intraoperative death. Perioperatively, five surgery related deaths were observed (5/28, related mortality 17.9%) with multiple organ failure as the cause of death in all cases. All of these deaths followed emergency operations (5/14 = 35.7%) and all were observed in patients with septic abdominal complications. In contrast, even very extensive procedures were performed electively without related mortality (0/14, P = 0.02). During the first month after transplantation, major surgery was associated with a 50% (3/6) mortality, for late interventions mortality was 9.1% (2/22; P = 0.047).nnnCONCLUSIONSnPulmonary transplant recipients showed a high incidence of conditions requiring surgical intervention. As expected, septic complications, especially during the immediate post transplant period, carried a very poor prognosis. However, it was reassuring to observe that even extensive surgical procedures could be performed safely without associated mortality in the elective setting.

Acute hyponatremia after cardioplegia by histidine-tryptophane-ketoglutarate – a retrospective study

BackgroundHyponatremia is the most common electrolyte disorder in hospitalized patients and is known to be associated with increased mortality. The administration of antegrade single-shot, up to two liters, histidine-tryptophane-ketoglutarate (HTK) solution for adequate electromechanical cardiac arrest and myocardial preservation during minimally invasive aortic valve replacement (MIAVR) is a standard procedure. We aimed to determine the impact of HTK infusion on electrolyte and acid–base balance.MethodsIn this retrospective analysis we reviewed data on patient characteristics, type of surgery, arterial blood gas analysis during surgery and intra-/postoperative laboratory results of patients receiving surgery for MIAVR at a large tertiary care university hospital.ResultsA total of 25 patients were included in the study. All patients were normonatremic at start of surgery. All patients developed hyponatremia after administration of HTK solution with a significant drop of serum sodium of 15u2009mmol/L (pu2009<u20090.01). Measured osmolality did not change during all times of surgery compared to start of surgery (pu2009=u20090.28 – pu2009=u20090.79), indicating isotonic hyponatremia. After administration of HTK solution pH fell significantly due to development of metabolic acidosis.ConclusionsAcute hyponatremia during cardioplegia with HTK solution is isotonic and should probably not be corrected without presence of hypotonicity as confirmed by measurement of serum osmolality.

Cefazolin and linezolid penetration into sternal cancellous bone during coronary artery bypass grafting

OBJECTIVESnDeep sternal wound infection is a severe complication after cardiac surgery. Insufficient antibiotic target site concentrations may account for variable success of perioperative prophylaxis. Therefore, we measured perioperative penetration of cefazolin and of linezolid into sternal cancellous bone after sternotomy in coronary artery bypass grafting (CABG) patients by in vivo microdialysis.nnnMETHODSnNine patients underwent CABG using a skeletonized left internal mammary artery. Standard antibiotic prophylaxis consisted of 4 g cefazolin prior to skin incision and additional 2 g during skin closure. In addition, 600 mg of linezolid were administered prior to skin incision and after 12 h for study purposes. Two microdialysis probes were inserted into the sternal cancellous bone (left and right side) after sternotomy.nnnRESULTSnFirst mean peak cefazolin and linezolid plasma concentrations were 273 ± 92 µg/ml and 22.1 ± 8.9 µg/ml, respectively. Mean peak concentrations of antibiotics in sternal cancellous bone on the left and right sternal side were 112 ± 59 µg/ml and 159 ± 118 µg/ml for cefazolin and 10.9 ± 4.0 µg/ml and 12.6 ± 6.1 µg/ml for linezolid, respectively. Cefazolin exceeded the required tissue concentrations for relevant pathogens by far, but linezolid did not gain effective tissue concentrations in all patients for some relevant pathogens. Mammary artery harvesting had no significant effect on antibiotic tissue penetration.nnnCONCLUSIONSnDirect measurement of antibiotic concentration in sternal cancellous bone with in vivo microdialysis is technically demanding but safe and feasible. We could demonstrate sufficient antibiotic coverage with our standard cefazolin-dosing regimen in the sternal cancellous bone during cardiac surgery. Mammary artery harvesting had no clinically relevant effect on tissue penetration. Linezolid concentrations were not sufficient for some relevant pathogens.

Prolonged venoarterial extracorporeal membrane oxygenation after transplantation restores functional integrity of severely injured lung allografts and prevents the development of pulmonary graft failure in a pig model

OBJECTIVEnProlonged venoarterial extracorporeal membrane oxygenation support during transplantation provides reduction of pulmonary artery flow and allows for protective ventilation. This approach might have the potential to restore function of lungs that would be unsuitable for transplantation.nnnMETHODSnLeft lung transplantation was performed on 16 pigs. Lungs from brain-dead animals were stored for 22 hours at 4 degrees C. Recipients in group A (n = 8) underwent transplantation without cardiopulmonary support followed by ventilation with 10 mL/kg body weight tidal volume. Animals in group B (n = 8) underwent transplantation during venoarterial extracorporeal membrane oxygenation, which was continued for 22 hours, and received low-tidal-volume (5 mL/kg body weight) ventilation. One hour after transplantation, the right lung was excluded. Graft function was compared immediately after exclusion of the contralateral lung (time point 1), 1 hour later (time point 2), and 1 hour after discontinuation of extracorporeal membrane oxygenation (time point 3).nnnRESULTSnFour animals in group A did not reach time point 2; all died of pulmonary edema. All animals in group B survived, and at time point 3, the mean Pao(2) value was 323 +/- 129 mm Hg. At time point 2, oxygenation and lung compliance were higher in group B than in group A, whereas pulmonary artery pressure was lower. The same was true when comparing results of group B at time point 3 with results of group A at time point 2.nnnCONCLUSIONSnTransplantation during extracorporeal membrane oxygenation with continued use for 24 hours restores function of damaged donor lungs. This could expand the donor pool through wider use of marginal donors.