Inhalation of hydrogen gas protects against mitomycin-induced pulmonary veno-occlusive disease.

BACKGROUND: As a subtype of pulmonary hypertension (PH), pulmonary veno-occlusive disease (PVOD) is devastating and life-threatening disease without effective therapy. Hydrogen has been reported to exhibits antioxidant and anti-inflammatory effects in a rat model induced by monocrotaline of PH. In this study, we investigated the effects of inhaled hydrogen gas on the prevention and treatment of PVOD induced by mitomycin C (MMC) in rats. METHODS: PVOD was induced in female Sprague-Dawley rats through intraperitoneal injection of MMC at a concentration of 3 mg·kg- 1·wk- 1 for 2 weeks. Inhalation of hydrogen gas (H2) was administered through a designed rat cage concurrently or two weeks after MMC administration. The severity of PVOD was assessed by using hemodynamic measurements and histological analysis. The expression levels of general control nonderepressible 2 (GCN2), nuclear factor erythroid 2-related factor-2 (Nrf2), heme oxygenase-1 (HO-1) and endothelial-to-mesenchymal transition (EndoMT) related proteins in lung tissue were measured. Levels of lipid peroxidation pro-inflammatory cytokines in serum were determined. RESULTS: Inhaled H2 improved hemodynamics and right heart function, reversed right ventricular hypertrophy, and prevented pulmonary vessel reconstitution in both prevention and treatment approaches. It decreased malondialdehyde (MDA) levels in the serum and the expression of NADPH oxidase 1 (NOX-1) in lung tissue. It regulated Nrf2/HO-1 signaling pathway and anti-inflammatory factor GCN2 in lung tissue, accompanied by a decrease in macrophages and pro-inflammatory cytokines. Our data suggested that H2 inhalation effectively countered EndoMT induced by MMC, as evidenced by the detection of endothelial markers (e.g., VE-cadherin and CD31) and mesenchymal markers (e.g., vimentin and fibronectin). Further research revealed that H2 preserved p-Smad3 and induced p-Smad1/5/9. CONCLUSION: Inhalation of H2 effectively inhibits the pathogenesis of PVOD induced by MMC in rats. This inhibitory effect may be attributed to the antioxidant and anti-inflammatory properties of H2.

Progression of vascular remodeling in pulmonary vein obstruction.

OBJECTIVES: Pulmonary vein obstruction (PVO) frequently occurs after repair of total anomalous pulmonary vein connection with progression of intimal hyperplasia from the anastomotic site toward upstream pulmonary veins (PVs). However, the understanding of mechanism in PVO progression is constrained by lack of data derived from a physiological model of the disease, and no prophylaxis has been established. We developed a new PVO animal model, investigated the mechanisms of PVO progression, and examined a new prophylactic strategy. METHODS: We developed a chronic PVO model using infant domestic pigs by cutting and resuturing the left lower PV followed by weekly hemodynamic parameter measurement and angiographic assessment of the anastomosed PV. Subsequently, we tested a novel therapeutic strategy with external application of rapamycin-eluting film to the anastomotic site. RESULTS: We found the pig PVO model mimicked human PVO hemodynamically and histopathologically. This model exhibited increased expression levels of Ki-67 and phospho-mammalian target of rapamycin in smooth muscle-like cells at the anastomotic neointima. In addition, contractile to synthetic phenotypic transition; that is, dedifferentiation of smooth muscle cells and mammalian target of rapamycin pathway activation in the neointima of upstream PVs were observed. Rapamycin-eluting films externally applied around the anastomotic site inhibited the activation of mammalian target of rapamycin in the smooth muscle-like cells of neointima, and delayed PV anastomotic stenosis. CONCLUSIONS: We demonstrate the evidence on dedifferentiation of smooth muscle-like cells and mammalian target of rapamycin pathway activation in the pathogenesis of PVO progression. Delivery of rapamycin to the anastomotic site from the external side delayed PV anastomotic stenosis, implicating a new therapeutic strategy to prevent PVO progression.

Conventional repair of total anomalous venous drainage without primary sutureless technique: surgical tips to prevent pulmonary vein obstruction.

OBJECTIVES: Although primary sutureless technique for total anomalous pulmonary venous drainage has been introduced to reduce postoperative pulmonary vein obstruction (PVO), controversy still exists about superiority of the procedure between the conventional repair and primary sutureless technique at the initial repair. In our unit, the conventional repair has been consistently used based on four important surgical policies: (1) mark incision lines between 2 chambers to gain anatomically natural alignment, (2) place precise stitches by "intima-to-intima" using monofilament suture, (3) adequate orifice size should be guaranteed in greater than expected mitral valve size, (4) do not hesitate to undertake a redo additional anastomosis by a different approach when an echocardiography shows the velocity more than 1.5 m/s. This study aims to evaluate mid-term outcome of the conventional repair for total anomalous pulmonary venous drainage. METHODS: Between 2004 and 2016, consecutive 15 patients who underwent the conventional repair without the primary sutureless technique were included in this study. Survival, Freedom from reoperation, and PVO were retrospectively reviewed. RESULTS: Mean follow-up period was 4.6 ± 3.7 years. Except for one patient who died of uncontrollable pleural effusion, all other patients survived with 5-year survival rate of 93.3%. For the 14 survivors, there was no PVO, nor reoperation. CONCLUSIONS: Following these policies, the mid-term outcome of the conventional total anomalous pulmonary venous drainage repair was excellent without the primary sutureless technique showing no obstruction. The conventional repair can be safely applied at the initial operation when the morphological condition allows for it.

Rivaroxaban lessens the number of thrombi in the left atrium and right lower pulmonary vein, as illustrated by transoesophageal echocardiography but not 80-MDCT.

Stroke is a clinically important problem. A left atrial thrombus is known as a cause of ischaemic stroke. A pulmonary vein thrombus (PVT) is thought to be rare; however, PVT is common in elderly patients. Additionally, images of PVT with transoesophageal echocardiography (TEE) following treatment have not been well contrasted with that from either 64 or 80-slice multidetector CT (80-MDCT). The images of such changes depicted by TEE remain unknown. An 87-year-old man with hypertension was examined by 80-MDCT and TEE to check the cardiac thrombus. Although 80-MDCT did not depict the thrombus, TEE depicted the thrombus in the left atrium and right lower pulmonary vein (RLPV) clearly. After 6 months of rivaroxaban treatment, the thrombus in the RLPV decreased slightly and the thrombus in the left atrium became small and lucent, as estimated with TEE. Rivaroxaban decreased the size of the thrombus and changed the quality of the thrombus.

Surgical outcomes of total anomalous pulmonary venous connection repair: a 22-year experience.

BACKGROUND: Total anomalous pulmonary venous connection (TAPVC) is a rare congenital heart disease (CHD), whose surgical repair is associated with high mortality and reoperation rates. We sought to identify predictors of early and late outcomes. METHODS: Data from medical records of patients who underwent surgical repair for TAPVC from 1989 to 2012 were included. The patients were divided in two groups, according to absence or presence of associated major CHDs. RESULTS: Forty-six patients were included (M/F: 26/20, median age 26 days, interquartile range 15 to 59, median weight 3.350 kg, interquartile range 1800 to 4470). Anatomic types of TAPVC were: supracardiac in 48%, intracardiac in 20%, infracardiac in 20%, and mixed in 12%; TAPVC was obstructive in 33%; TAPVC was isolated in 63%, complex in 37%. Single ventricle physiology was present in 11 patients, heterotaxy in eight patients. Overall operative mortality was 19.6% (9/46): 6.9% in isolated TAPVC, 41.2% in complex type (p-value: 0.002). It was associated with low weight at intervention (<3 kg, p = 0.027), single ventricle physiology (p = 0.047), and aortic cross-clamp time >60 minutes (p = 0.097). At a median follow-up of 2.97 years (range 43 days to 22 years, 91% complete), there were nine late deaths (24.3%); 15 patients (40.5%) had major events (including late death). Multivariate analysis of event-free survival showed worse outcome in the complex group (p = 0.001). CONCLUSION: Surgical mortality and morbidity remain consistent in patients with TAPVC and associated major CHD, while the isolated type shows excellent outcomes. Pulmonary vein obstruction is a rare but highly lethal complication. doi: 10.1111/jocs.12399 (J Card Surg 2014;29:678-685).

Hematopoietic stem cell transplantation practice variation among centers in the Eastern Mediterranean Region (EMRO): Eastern Mediterranean Bone Marrow Transplantation (EMBMT) group survey.

INTRODUCTION: This practice survey is conducted to analyze clinical hematopoietic stem cell transplantation (HSCT) practice variability among centers in the WHO Eastern Mediterranean Region (EMRO), as represented by the Eastern Mediterranean Blood and Marrow Transplantation (EMBMT) group. METHOD: This internet based survey was completed by the medical program directors of the EMBMT centers; 17 centers participated. The survey collected data on various clinical aspects of HSCT practice. RESULTS: Consistency in pre HSCT cardiac (100%), pulmonary (82%) and viral screen (100%) was observed. Obtaining informed consent was universal. Pre-HSCT psychological assessment is practiced in 50% of the centers. All centers used single-bedded rooms with HEPA filters. Visitor policy during neutropenic phase and the use of gowns, masks or gloves when examining patients varied among centers. MRSA/VRE screen and use of low bacterial diet were applied in 65% and 82%, respectively. Anti-bacterial prophylaxis is employed in 58% (Auto-SCT) and 60% (Allo-SCT) of the centers. Drug choice varied (cotrimoxazole, ciprofloxacin, levofloxacin, piperacillin-tazobactam); 60% of the centers used penicillin prophylaxis in GVHD patients. PCP prophylaxis is applied in 58% (Auto-SCT) and 87% (Allo-SCT) of the centers; cotrimoxazole is usually used. Anti-viral prophylaxis with acyclovir or, less commonly, valacyclovir is used in 70% (Auto-SCT) and 93% (Allo-SCT) of centers. Anti-fungal prophylaxis is applied in 70% (Auto-SCT), 93% (myeloablative Allo-SCT) and 87% (reduced intensity [RIC] Allo-SCT). Fluconazole is used in all Auto-SCT and majority of Allo-SCT recipients; few centers used other agents (itraconazole, voriconazole, amphotericin B) in Allo-SCT. Prophylactic GCSF use varied among centers: Auto-SCT 77%, myeloablative Allo-SCT 33%, RIC Allo-SCT 27%. Use of ursodeoxycholic acid for venoocclusive disease (VOD) prophylaxis is variable: 60% (Allo-SCT) and 12% (Auto-SCT). Cyclosporine/methotrexate is the most commonly used GVHD prophylaxis in myeloablative Allo-SCT (93%); heterogeneity was seen in RIC SCT. Treatment of steroid refractory acute GVHD varied (ATG 53%, higher steroid dose 40%). CMV monitoring varied between antigenemia (53%) and PCR (40%) techniques. Pre-emptive anti CMV therapy is used in 86% of the centers, while 7% used routine CMV prophylaxis; 7% had no specific CMV management policy. CONCLUSION: Consistency was observed in areas of pre-SCT work up, use of single rooms, HEPA filters and GVHD prophylaxis. Heterogeneity is observed in other practice aspects including other isolation measures, anti-microbial prophylaxis, VOD prophylaxis, growth factor use and treatment of steroid refractory GVHD. Further studies are needed to probe the impact of such practice variations on post-transplant outcome and to ascertain the best clinical practice approach.

Is double or single patch for sinus venosus atrial septal defect repair the better option in prevention of postoperative venous obstruction?

A best evidence topic in cardiac surgery was constructed according to a structured protocol. The question addressed was, 'Is double or single patch for sinus venous atrial septal defect repair the better option in prevention of postoperative venous obstruction?' Altogether seventy nine papers were found using the reported search; ten papers were identified that provided the best evidence to answer the question. The authors, journal, date, country of publication, patient group, study type, relevant outcomes and results of were tabulated. Three hundred and thirty four patients had single-patch with 7 (2.1%) having venous obstruction (venous obstruction; defined as obstruction at the atriocaval anastomosis and/or the right superior pulmonary vein) while 130 had double-patch with 3 (2.3%) having venous obstruction. However, when the three randomised studies were reviewed, 101 had single-patch and 67 had double-patch with 7 (7%) and 4 (6%) having venous obstruction respectively. Similarly, another randomised study that considered solely the two surgical options with eighteen patients who had single-patch repair as group A and 19 patients who had double-patch repair as group B with six patients in group A and 2 patients in group B having significant superior vena cava-right atrium pressure gradient of more than 6 mmHg. Nine patients in group A had a significant gradient causing turbulence across the right superior pulmonary vein at the level of the patch, whereas no patients in group B had turbulence across the pulmonary vein. The double-patch technique technically offered better results in terms of superior vena cava narrowing and gradient across the pulmonary vein without any increase in complications. However, in order to reduce postoperative venous obstruction while using the single-patch repair method, the adoption of the transcaval approach yielded excellent results, with unobstructed pulmonary and systemic venous flow as in 141 patients who had this method of repair only one patient had venous obstruction. In conclusion, the evidence was in support of the adoption of double-patch or the use of the transcaval repair technique when the single patch technique was used as a better option to avoid venous obstruction.

Bifurcation angioplasty using drug eluting stents of post-AF ablation severe pulmonary vein stenosis.

A 53-year-old man with long-standing persistent AF underwent multiple ablation procedures. A presentation with hemoptysis led to a left pulmonary artery wedge angiography and thoracic computed tomography (CT) scan, which revealed a tight bifurcation stenosis of the left superior pulmonary vein (LSPV). This was treated by angioplasty with drug-eluting stents to avoid restenosis by bare-metal stent implantation in small diameter PVs as already described. After predilatation, two 4 × 32-mm and a 3 × 20-mm Taxus® Liberté stents (Boston Scientific, Natick, MA, USA) were deployed across upper and lower LSPV branches and the ostio-antral segment. Twenty-two month follow-up CT angiography showed patent stents in the LSPV, without in-stent restenosis (no arrhythmia or hemoptysis at 24-month follow-up).

Intra-atrial repair for total anomalous pulmonary venous connection.

The natural history of total pulmonary venous connection (TAPVC) is unfavorable per se. We describe a modified technique of intra-atrial repair in infants with supra- and infracardiac TAPVC. Twenty patients were treated. The median age at repair was 16 (range 3-62) days. Echocardiography and multi-detector row computed tomography were used to confirm the diagnosis. Our policy was to perform surgery on an urgent basis whenever there was a sign of severe pulmonary congestion or hypoxia. The procedures performed in cardiopulmonary bypass (CPB) were established in a standard fashion using bi-caval cannulation and moderate hypothermia. A novel modification of our surgical technique is the H-shaped instead of simple straight incision of pulmonary venous confluence and intra-atrial sewing. H-shaped incision of pulmonary venous confluence can increase the anastomotic area than simply straight-line incision and create a large anastomosis with maximal use of the venous confluence and atrial tissue. Intra-atrial repair can avoid torsion and rotation of the pulmonary veins. There were no operative deaths and no recurrent pulmonary venous obstruction was noted after a mean period of 2 ± 0.8 years (range: 12-20 months). Intra-atrial repair provides excellent results for primary repair of supra- and infracardiac TAPVC in infants.

Primary palliative stenting against obstructive mixed-type total anomalous pulmonary venous connection associated with right atrial isomerism.

This case report presents a low-birth-weight neonate who received primary stent implantation as a long-term palliative intervention for obstructive mixed-type total anomalous pulmonary venous connection (TAPVC) without common pulmonary venous chamber associated with right atrial isomerism, which was considered difficult to surgically repair in the neonatal period. Stent redilation with balloon catheters was repeated for in-stent stenosis from neointimal proliferation, resulting in successful TAPVC repair with cavopulmonary connection at 17 months of age.

Development of novel drug-eluting biodegradable nano-fiber for prevention of postoperative pulmonary venous obstruction.

Pulmonary venous obstruction (PVO) after correction of total anomalous pulmonary venous connection (TAPVC) frequently occurs due to intimal-hyperplasia and the required re-operation. We have developed a novel sustained-release drug delivery system, using Tacrolimus-eluting biodegradable nano-fiber (TEBN). It consists of nano-scale fiber composed of biodegradable polymer and Tacrolimus. This study evaluated the effects of TEBN for prevention of venous anastomotic stricture in a rat model to apply to PVO operation. Tacrolimus was incorporated into poly (L-lactide-co-glycolide). The venous stricture model was made by rat inferior vena cava anastomosis. The IVC anastomosis was covered with TEBN with 1.0 wt% Tacrolimus (n=12) or without TEBN as a control (n=12), and evaluated histologically at 1, 2, and 4 weeks after operation. The ratio of intimal area was significantly reduced in the TEBN group compared with the control group (ratio; 1 week: 0.43+/-0.26 vs. 0.07+/-0.04, P=0.04, 2 weeks: 0.39+/-0.19 vs. 0.05+/-0.02, P=0.01, 4 weeks: 0.31+/-0.15 vs. 0.09+/-0.04, P=0.03, control vs. TEBN, respectively). Histological findings showed endothelialization along the inner surface of the vein even in TEBN. The TEBN reduced intimal hyperplasia and preserved endothelialization even in a venous stricture. These results suggested that this strategy might be useful for prevention of recurrent PVO after TAPVC correction.

[Postoperative venous thromboembolic complications - real threat and modern preventive methods].

Prospective study included 244 patients, who underwent general surgery, gynecological or urological surgical interventions. The rate of postoperative venous thrombotic complications was analyzed in accordance with preventive strategy. It was shown that high-technology methods (both physical and pharmacological) in combination with other diagnostic and therapeutic interventions can improve the efficacy of PVTC prevention. Diagnostic algorithms for PVTC prevention and early diagnosis were developed and implemented into clinical practice.

Protective effects of S-nitrosoalbumin on lung injury induced by hypoxia-reoxygenation in mouse model of sickle cell disease.

Nitric oxide (NO) is a potential new therapeutic agent for sickle cell disease (SCD). We investigated the effects of NO donor on hypoxia-induced acute lung injury that occurs when transgenic sickle cell SAD mice are exposed to chronic hypoxia, a model for lung vasoocclusive sickle cell events. In wild-type and SAD mice, intraperitoneal injection of S-nitrosoalbumin (NO-Alb) produced no significant hematologic changes under room air conditions, whereas it induced mild temporary hypotension and inhibition of platelet aggregation. NO-Alb administration (300 mg/kg ip twice a day, equivalent to 7.5 microM NO) in wild-type and SAD mice exposed to 46 h of hypoxia (8% oxygen) followed by 2 h of normoxia resulted in 1) reduction of the hypoxia-induced increase in blood neutrophil count, 2) prevention of hypoxia-induced increased IL-6 and IL-1beta levels in bronchoalveolar lavage, 3) reduction of the lung injury induced by hypoxia-reoxygenation, 4) prevention of thrombus formation, and 5) prevention of hypoxia-induced increase of lung matrix metalloproteinase-9 gene expression. These effects provide new insights into the possible use of NO-Alb in the treatment of acute lung injury in SCD.

Anti-thrombin III in the management of hematopoietic stem-cell transplantation-associated toxicity.

OBJECTIVE: To describe the evidence assessing the use of anti-thrombin III (AT-III) in the management of toxicity associated with hematopoietic stem-cell transplantation (HSCT)-conditioning regimens. DATA SOURCES: Clinical literature was accessed through conference proceedings, EMBASE, the Cochrane database, and MEDLINE (1966-December 2003). STUDY SELECTION AND DATA EXTRACTION: Case reports, small case series, case-control and cohort studies, and randomized controlled trials of AT-III in HSCT were evaluated. Publications examining AT-III use in the non-HSCT setting were also explored. Key search terms included AT-III, transplantation, and veno-occlusive disease (VOD). DATA SYNTHESIS: Severe VOD and ensuing multiple organ dysfunction is associated with high mortality in HSCT. A low AT-III level has been shown to correlate with the development of organ dysfunction. Phase II trials, case series, and one small, randomized, placebo-controlled study suggest a benefit when AT-III therapy is instituted early in the course of VOD/multiple organ dysfunction syndrome. In all of these reports, AT-III use was devoid of adverse events. CONCLUSIONS: Although further studies are needed to ascertain the optimal target level, method, and duration of administration, AT-III is still a viable alternative for the treatment of severe VOD and ensuing multiple organ dysfunction.

[Surgical treatment of total anomalous pulmonary venous connection--clinical aspects of pulmonary venous obstruction].

During November 1986 and May 1997, 19 patients with total anomalous pulmonary venous connection (TAPVC) underwent repair surgery. 20 operations including two reoperations were performed. 8 of 19 patients were classified as Darling type Ia, 5 as type IIa, 4 as type III and 2 patients were type IV. Two patients were operated under emergency circumstances within 24 hours after admission, 7 patients were after a short term stabilization of 4.4 days, and the other 11 patients received surgical treatment after a mean of 8.8 days as scheduled cases. For the anostomosis, the common pulmonary venous chamber or the vertical vein was connected with the left atrium in type Ia and III cases; in type IIa and IV cases the cut-back method was performed. Persistent pulmonary hypertension and post-operative pulmonary venous obstruction (PVO) affected the post-operative clinical course. Persistent pulmonary hypertension caused the death of one patient with type IIa and III each, just after operation. One type IV patient died 50 days after operation. The autopsy revealed post-operative obstructions of the remote parts of the pulmonary veins on the anostomosis site. Two patients (type IIa, III) successfully underwent reoperation due to PVO. Post-operative cardiac catheterization was performed after 12 month in 12 cases. Persistent pulmonary hypertension was found in 4 patients, and a type III patient was reoperated because of stenosis of the anostomosis site. The other three patients had persistent pulmonary hypertension without any demonstrable PVO. Persistent pulmonary hypertension and PVO are combined as TAPVC complex. The difficulty to reoperated patients with persistent pulmonary hypertension caused by PVO is one major problem. So preoperative prevention of PVO by normalization the morphologic changes of the pulmonary veins by using drugs could be a different view point in TAPVC therapy after the initial operation.

Down syndrome as a factor influencing hemodynamic response to pulmonary artery banding.

The hemodynamic response to pulmonary artery banding (PAB) in relation to the preoperative pulmonary/systemic vascular resistance (Rp/Rs) ratio and to the timing of surgery, with special regard to Down syndrome, was investigated in 56 nonconsecutive pediatric patients aged 3 days to 6 months (mean 2.5 months) with simple and complex congenital shunt-related cardiac malformations. Among the non-Down patient group (39 patients; mean age 6.9 weeks) there was a good hemodynamic response in all but three cases, irrespective of the preoperative Rp/Rs ratio; these three poor responders had preoperatively normal or nearly normal Rp/Rs ratios (Rp/Rs < 0.3) and were affected postoperatively by lung complications. In the Down patient group (17 patients; mean age 8.2 weeks) the mean preoperative as well as the mean postoperative Rp/Rs ratio was higher than in the non-Down patient group (preoperative Rp/Rs 0.49 versus 0.32; postoperative Rp/Rs 0.31 versus 0.18). There was a good hemodynamic response in all five patients with Down syndrome who had preoperative normal or nearly normal pulmonary vascular resistance ratios (Rp/Rs < 0.3). Among 12 patients with Down syndrome and preoperative increased resistance ratios (Rp/Rs > 0.3) PAB did not cause a reduction in pulmonary vascular resistance (PVR) in five patients (postoperative Rp/Rs 0.49-1.00), all operated on at more than 6 weeks of age. PAB resulted in effective reduction of postoperative Rp/Rs ratios (range 0.10-0.27) in seven patients, six of them younger and one older than 6 weeks at the time of the banding procedure. In conclusion, patients with Down syndrome and shunt-related cardiac malformations (predominantly total atrioventricular canal cases) in general have higher pre- and postoperative Rp/Rs ratios than non-Down children and also have a higher potential for developing pulmonary vascular obstructive disease despite hemodynamically effective PAB. Especially in children with Down syndrome and pathologically high resistance ratios, PAB, if indicated, should be performed as early as possible.

[A case report of Darling's classification Ib total anomalous pulmonary venous return with an unusual left pulmonary vein].

A radical correction involving Vargas's method and a direct anastomosis between the left pulmonary vein (PV) and left atrium (LA) was performed in a 29 day-old infant with supracardiac type Ib total anomalous pulmonary venous return (TAPVR) and an unusual form of the left PV. the left upper and lower PVs drained into a left "common" PV that was just behind the LA, and then into the right pleural cavity. The left common PV was located cephalad to the normal course and received blood from the right lower and upper PVs and drained into the supra-vena cava (SVC). The junction of the SVC and the right PV was slightly stenotic. Vargas's method is a useful technique for Darling's classification Ib TAPVR even in cases without the common PV situated behind the LA. But this patient had a left common PV and it was possible either to anastomose the common PV and LA directly or to perform Vargas's technique. We performed both procedures to prevent left PV obstruction (PVO). Cineangiography performed 2 months after surgery showed that a large amount of blood from the right and left PV drained into the LA through the common PV-LA route. These procedures, which create a dual PV channel, reduce the risk of PVO, so they are useful for radical correction of Darling's Ib type TAPVR.

Absorbable polydioxanone suture and results in total anomalous pulmonary venous connection.

BACKGROUND: Despite theoretical advantages of absorbable suture in the growing vascular anastomosis, there has not been a documented advantage over nonabsorbable suture in preventing late anastomotic stenosis in total anomalous pulmonary venous connection (TAPVC). METHODS: We reviewed our experience from 1982 to 1994 with 65 hospital survivors of total TAPVC repair to examine the influence of suture type on survival and incidence of late pulmonary venous obstruction. From 1982 until 1988, we used continuous nonabsorbable polypropylene suture for the pulmonary venous-left atrial anastomosis in supracardiac, infracardiac, and mixed types of TAPVC: In 1989, we adopted a running absorbable polydioxanone suture technique. Cardiac catheterization and echocardiography were used to evaluate late pulmonary venous obstruction. RESULTS: Late pulmonary venous obstruction occurred in 17% (4/23) of survivors after repair with polypropylene suture compared with 3.2% (1/32) after repair with polydioxanone suture (p < 0.05). There were no instances of late pulmonary venous obstruction in the intracardiac TAPVC group (0/10). All late pulmonary venous obstructions occurred within 16 months after operation. The actuarial 3-year and 5-year freedom from late pulmonary venous obstruction was 100% for intracardiac TAPVC, 96% for the polydioxanone group, and 81% for the polypropylene group. Five patients died late (5/65, 7.7%), 3 in the polypropylene suture group (3/23, 13%) and 2 in the polydioxanone group (2/32, 6%). CONCLUSIONS: Continuous absorbable polydioxanone suture for the repair of TAPVC results in a low incidence of late pulmonary venous obstruction and death and appears to offer advantages over a continuous nonabsorbable suture. A continuous nonabsorbable suture may limit growth of a vascular anastomosis, particularly one involving a "low-pressure" anastomosis such as in the repair of TAPVC: