Project description:Pulmonary artery anastomosis (PAA) is a critical step in lung transplantation. The conventional approach involves end-to-end anastomosis, which can lead to arterial tortuosity, oozing, stenosis, and thrombosis. Here, we present a modified PAA technique for lung transplantation. The anesthesia protocol and the incision for lung transplantation adhere to standard lung transplantation protocols. The primary innovation is the enhanced pulmonary anastomosis technique. The donor and recipient artery stumps are adjusted to restore their natural anatomical alignment. The donor-recipient stump is everted, ensuring precise alignment of the intima of the donor and recipient arteries. Both ends of the anastomosis are secured using 5-0 Prolene sutures to ensure stability and traction, followed by continuous suturing. In this study, seven patients underwent PAA using this novel technique. Notably, no bleeding was observed upon unveiling and deaerating the anastomosis, eliminating the need for additional sutures. Furthermore, no pulmonary artery torsion or significant prolongation of the anastomotic procedure was observed. Postoperative computed tomography of the chest revealed no anastomotic stenosis or mural thrombosis. This novel cuff anastomosis technique can reduce the risk of thrombosis and prevent torsion and stenosis in the reconstructed artery.
Project description:Donor-to-recipient lung size matching at lung transplantation (LTx) can be estimated by the predicted total lung capacity (pTLC) ratio (donor pTLC/recipient pTLC). We aimed to determine whether the pTLC ratio is associated with the risk of primary graft dysfunction (PGD) after bilateral LTx (BLT).We calculated the pTLC ratio for 812 adult BLTs from the Lung Transplant Outcomes Group between March 2002 to December 2010. Patients were stratified by pTLC ratio >1.0 ("oversized") and pTLC ratio ?1.0 ("undersized"). PGD was defined as any ISHLT Grade 3 PGD (PGD3) within 72 hours of reperfusion. We analyzed the association between risk factors and PGD using multivariable conditional logistic regression. As transplant diagnoses can influence the size-matching decisions and also modulate the risk for PGD, we performed pre-specified analyses by assessing the impact of lung size mismatch within diagnostic categories.In univariate analyses oversizing was associated with a 39% lower odds of PGD3 (OR 0.61, 95% CI, 0.45-0.85, p = 0.003). In a multivariate model accounting for center-effects and known PGD risks, oversizing remained independently associated with a decreased odds of PGD3 (OR 0.58, 95% CI 0.38 to 0.88, p = 0.01). The risk-adjusted point estimate was similar for the non-COPD diagnosis groups (OR 0.52, 95% CI 0.32 to 0.86, p = 0.01); however, there was no detected association within the COPD group (OR 0.72, 95% CI 0.29 to 1.78, p = 0.5).Oversized allografts are associated with a decreased risk of PGD3 after BLT; this effect appears most apparent in non-COPD patients.
Project description:ObjectivesMechanical ventilation tidal volumes are usually set according to an estimate of patient size in millilitres (ml) per kilogram (kg) body weight. We describe the relationship between donor-recipient lung-size mismatch and postoperative mechanical ventilation tidal volumes according to recipient- and donor-predicted body weights in a cohort of bilateral lung transplant patients.MethodsA most-undersized (10 patients with lowest predicted total lung capacity [pTLC] ratio = pTLC-donor/pTLC-recipient), a most-oversized (10 patients with highest pTLC ratio) and best-matched subset (10 patients with predicted total lung capacity ratio closest to 1.0) were selected within a cohort of 70 patients. All tidal volumes during mechanical ventilation in the first 96 h after bilateral lung transplantation were recorded. Tidal volumes were expressed in ml and ml/kg-recipient-predicted body weights and ml/kg-donor-predicted body weights.ResultsPostoperative absolute tidal volumes (in ml) were comparable between subsets of patients with undersized, matched and oversized allografts (552 ± 103 vs 581 ± 107 vs 582 ± 104 ml), and tidal volumes in ml/kg-recipient-predicted body weights were also similar (8.8 ± 1.4 vs 9.3 ± 1.1 vs 9.8 ± 2.1). However, tidal volumes in ml/kg-donor-predicted body weights revealed significant differences between undersized, matched, and oversized subsets (11.4 ± 3.1 vs 9.4 ± 1.2 vs 8.1 ± 2.1, respectively; P < 0.05). Two patients developed primary graft dysfunction grade 3, both in the undersized subset. Four patients in the undersized group underwent tracheotomy (vs none in matched and one in oversized subset).ConclusionsDuring mechanical ventilation after bilateral lung transplantation, undersized allografts received relatively higher tidal volumes compared with oversized allografts when the tidal volumes were related to donor-predicted body weights.
Project description:BackgroundSize mismatch between donor lungs and a recipient thorax could affect the major determinants of maximal expiratory airflow: airway resistance, propensity of airways to collapse, and lung elastic recoil.MethodsA retrospective review of 159 adults who received bilateral lung transplants was performed. The predicted total lung capacity (pTLC) for donors and recipients was calculated based on sex and height. Size matching was represented using the following formula: pTLC ratio = donor pTLC / recipient pTLC. Patients were grouped according to those with a pTLC ratio > 1.0 (oversized) or those with a pTLC ratio ? 1.0 (undersized). Allograft function was analyzed in relation to the pTLC ratio and to recipient and donor predicted function.ResultsThe 96 patients in the oversized cohort had a mean pTLC ratio of 1.16 ± 0.13 vs 0.89 ± 0.09 in the 63 patients of the undersized group. At 1 to 6 months posttransplant, the patients in the oversized cohort had higher FEV(1)/FVC ratios (0.895 ± 0.13 vs 0.821 ± 0.13, P < .01) and lower time constant estimates of lung emptying (0.38 ± 0.2 vs 0.64 ± 0.4, P < .01) than patients in the undersized cohort. Although the FVCs expressed as % predicted for the recipient were not different between cohorts, the FVCs expressed as % predicted for the donor organ were lower in the oversized cohort compared with the undersized cohort (at 1-6 months, 52.4% ± 17.1% vs 65.3% ± 18.3%, P < .001). Kaplan-Meier estimates for the occurrence of bronchiolitis obliterans syndrome (BOS) showed that patients in the oversized cohort had a lower probability of BOS (P < .001).ConclusionsA pTLC ratio > 1.0, suggestive of an oversized allograft, is associated with higher expiratory airflow capacity and a less frequent occurrence of BOS.
Project description:ObjectivesThe mouse orthotopic lung transplantation (LTx) model is of enormous research value in lung transplantation. This study compares 2 anastomotic methods (anterior and posterior hilum anastomosis) of mouse LTx in term of difficulty, operation time, and postoperative effects.MethodsTwenty mice received LTx with slipknots for anterior hilum anastomosis (AH group), and 28 received LTx with a microvessel clip for posterior hilum anastomosis (PH group), all by a single surgeon. The operation time was recorded and the grafts were evaluated 24 hours after surgery.ResultsThe success rates in the recipient animals were 85% (17/20) in AH group and 89% (25/28) in PH group (P > .05). The recipient operation time and back table time in AH group were longer than those in PH group (52.8 ± 5.0 vs 47.3 ± 5.7 minutes, 27.8 ± 3.9 vs 25.3 ± 2.8 minutes, P < .05), but the warm ischemia time did not differ significantly (13.1 ± 2.1 vs 12.2 ± 2.6 minutes, P = .258), meaning that the time discrepancies predominantly originated from the hilum treatment. In AH group, 2 cases failed due to pulmonary venous thrombosis and atelectasis respectively at 24 hours after LTx, but none failed in PH group. No significant difference was observed in the postoperative performance of the successful recipients (thoracic radiographs, macroscopic appearance, oxygenation index, pulmonary compliance, pathologic changes) between the 2 groups.ConclusionsCompared with anterior hilar anastomosis, posterior hilum anastomosis with a microvessel clip is less complicated and less time-consuming in the management of hilar structures and causes fewer postoperative complications.
Project description:BackgroundSurgical techniques of liver transplantation have continually evolved and have been modified. We retrospectively analyzed a single-center case series and compared the advantages and disadvantages of each method.MethodsSix-hundred and seventy-four recipients' perioperative data were assessed and analyzed stratified by different surgical technics [modified classic (MC), modified piggyback (MPB) and classic piggyback (CPB)].ResultsMELD score and Child-Pugh scores was significantly higher in CPB groups (P=0.008 and 0.003, respectively). Anhepatic time in MPB group was longer than those in CPB group (P<0.05). The operation duration in MPB group was significantly longer than those in MC group and CPB group (P=0.003). Three patients had outflow obstruction (P=0.035). The overall survival in MPB group were better than those in MC group and CPB group in general comparison (P<0.001). In patients with preoperative creatine >120 µmol/L, the overall survival in MC group was worst (P<0.001). In patients with a high MELD score (>24), the overall survival in MPB group tended to be the best (P<0.001).ConclusionsThe advantages and disadvantages are different for these three surgical techniques. A reasonable operation technique should be adopted considering the patient's unique condition to ensure the stability of hemodynamics.
Project description:From its identification as a distinct disease entity, understanding and management of pulmonary hypertension has continuously evolved. Diagnostic and therapeutic interventions have greatly improved the prognostic implications of this devastating disease, previously rapidly and uniformly fatal to one chronically managed by multi-disciplinary teams. Improved diagnostic algorithms and active research into biochemical signatures of pulmonary hypertension (PH) have led to earlier diagnosis of PH. Medical therapy has moved from upfront use of continuous intravenous prostaglandins to administration of combinations of oral medications targeting multiple pathways underlying this disease process. In addition to improved medical therapies, recently introduced interventions such as pulmonary endarterectomy and pulmonary artery balloon angioplasty for chronic thromboembolic pulmonary hypertension (CTEPH) give patients an increasing array of treatment options. Despite these many advances, lung transplantation remains the definitive treatment for patients with disease refractory to or progressing on best medical therapy. As our understanding of medical therapy has advanced, so to have best practices for lung transplantation. Recipient selection and approach to organ transplantation techniques have continuously evolved. Mechanical circulatory support has become increasingly employed to bridge patients through lung transplantation in the immediate post transplantation recovery. In this review, we give a history of lung transplantation for PH, an overview of PH, discuss current best practices and look to the future for insights into the care of these patients.
Project description:The recent development of tough tissue adhesives has stimulated intense interests among material scientists and medical doctors. However, these adhesives have seldom been tested in clinically demanding surgeries. Here we demonstrate adhesive anastomosis in organ transplantation. Anastomosis is commonly conducted by dense sutures and takes a long time, during which all the vessels are occluded. Prolonged occlusion may damage organs and even cause death. We formulate a tough, biocompatible, bioabsorbable adhesive that can sustain tissue tension and pressurized flow. We expose the endothelial surface of vessels onto a gasket, press two endothelial surfaces to the adhesive using a pair of magnetic rings, and reopen the bloodstream immediately. The time for adhesive anastomosis is shortened compared to the time for sutured anastomosis. We have achieved adhesive anastomosis of a great vein in transplanting the liver of a pig. After the surgery, the adhesive is absorbed, the vein heals, and the pig lives for over one month.