Late Obstruction Research Articles

Obstrucción del drenaje venoso hepático tras trasplante: resultados del tratamiento con endoprótesis autoexpandibles

ObjectivesTo evaluate the safety and patency of self-expanding stents to treat hepatic venous outflow obstruction after orthotopic liver transplantation. To evaluate differences in the response between patients with early obstruction and patients with late obstruction. Material and methodsThis is a retrospective analysis of 16 patients with hepatic venous outflow obstruction after liver transplantation treated with stents (1996-2011). Follow-up included venography/manometry, ultrasonography, CT, and laboratory tests. We did a descriptive statistical analysis of the survival of patients and stents, technical and clinical success of the procedure, recurrence of obstruction, and complications of the procedure. We also did an inferential statistical analysis of the differences between patients with early and late obstruction. ResultsThe mean follow-up period was 3.34 years (21-5,331 days). The technical success rate was 93.7%, and the clinical success rate was 81.2%. The rate of complications was 25%. The survival rates were 87.5% for patients and 92.5% for stents. The rate of recurrence was 12.5%. The rate of primary patency was 0.96 (95% CI 0.91-1) at 3 months, 0.96 (95% CI 0.91-1) at 6 months, 0.87 (95% CI 0.73-1) at 12 months, and 0.87 (95% CI 0.73-1) at 60 months. There were no significant differences between patients with early and late obstruction, although there was a trend toward higher rates of primary patency in patients with early obstruction (P=.091). ConclusionsTreating hepatic venous outflow obstruction after orthotopic transplantation with self-expanding stents is effective, durable, and effective. There are no significant differences between patients with early obstruction and those with late obstruction.

Late left ventricular outflow tract obstruction following mitral valve replacement

A 66-year old male presented with presyncope 14 years following mechanical mitral valve replacement. Echocardiography demonstrated the remainder of an elongated anterior mitral valve leaflet (AMVL) with systolic anterior motion obstructing the left ventricular outflow tract (Fig. 1 and Supplementary Video 1). Owing to previous intracranial bleeding, the completion of AMVL resection was performed via the bioprosthetic mitral valve. Supplementary material (Video 1) is available at EJCTS online. Video 1: Transthoracic echocardiography (long axis view) demonstrating the systolic anterior motion obstructing the left ventricle outflow tract in systole. In the initial operation the native valve was found degenerative with no interventricular septum hypertrophy. In the firsttime replacement the AMVL was partially resected, and it was found thrombosed and elongated in the second operation.

Different urodynamic patterns in female bladder outlet obstruction: Can urodynamics alone reach the diagnosis?

ObjectiveTo define the different urodynamic patterns in female bladder outlet obstruction (BOO) and to assess whether urodynamics alone can be relied on for the diagnosis. Patients and methodsThis prospective study included 60 clinically obstructed women and 27 with stress urinary incontinence as a control group. All patients had pressure-flow studies and were divided into four groups. Group A (control group, 27 patients) and group B (22) had a maximum urinary flow rate (Qmax) of >15mL/s and a detrusor pressure at Qmax (PdetQmax) of <30 or >30cm H2O, respectively. Group C (20 patients) and group D (18) had a Qmax of <15mL/s and a PdetQmax of >30 or <30cm H2O, respectively. ResultsThe mean Qmax for groups A, B, C, and D were 21.8, 21.9, 10.8 and 9.9mL/s, respectively, while the mean PdetQmax was 20.8, 40.4, 48.7, and 18.7cm H2O, respectively. The residual urine volume was <100mL in groups A and B but >100mL in groups C and D. When compared with group A, groups B–D had a significant difference in vesical pressure, groups B and C had a significant difference in PdetQmax, while Qmax, the maximum voided volume and residual urine volume were significantly different in groups C and D. Group A was obviously unobstructed, group B might have early obstruction, group C had compensated obstruction, while group D can be considered to have late de-compensated obstruction. ConclusionsBOO in females has three different urodynamic patterns, i.e. early, compensated and late obstruction. However, urodynamics should be combined with the clinical presentation and residual urine volume for an accurate diagnosis.

038 LARGER INFARCT SIZE ASSOCIATED WITH DYSGLYCEMIA AT THE TIME OF ST-ELEVATION MYOCARDIAL INFARCTION IS RELATED TO LATER PRESENTATION

Introduction Patients with dysglycaemia at the time of ST-elevation myocardial infarction (STEMI) have a worse prognosis. The reasons for this are not entirely clear. Admission hyperglycaemia has been associated with larger infarct size. The aims of this study were to examine the relation of acute and chronic glycaemic state to myocardial scar and salvage characteristics in patients with reperfused ST-elevation myocardial infarction. Methods Fifty-six patients treated for first ST-elevation myocardial infarction (STEMI) without a pre-existing diagnosis of Diabetes mellitus were prospectively enrolled between January and December 2010. Glycosylated haemoglobin (HbA1c) and glucose levels were sampled on admission to the emergency cardiac ward. Patients underwent cardiac magnetic resonance (CMR) examination during the index admission (median day 2 for CMR, IQR 2 days), with assessment of area-at-risk (STIRs), Infarct size (IS%), late microvascular obstruction (MVO%), and left ventricular function. Population characteristics are presented in table 1. There were no significant differences between patients receiving Primary Percutaneous Coronary Intervention (PPCI) or thrombolysis, so these were grouped for analysis. Patients were dichotomised into groups above and below the median both for admission glucose level and separately for HbA1c level before comparison between groups using Independent samples t test. Spearman9s rank correlation was used to compare non-parametric data. Correlations with a p Results When patients were dichotomised into glucose levels below ( Dichotomising patients by HbA1c into levels below the median ( Correlations between infarct characteristics and admission glucose and HbA1c are shown in table 2. Admission glucose correlated significantly with age and IS%, while HbA1c correlated significantly with time to reperfusion and MSI%. On multivariate linear regression analysis however, glucose was not a predictor of IS% (R=0.549, R2=0.302, Age t=3.441, p=0.001, time to reperfusion t=2.708, p=0.009, glucose- not significant), and HbA1c was not a predictor of MSI% (R=0.453, R2=0.206, age t=−2.529, p=0.015, time to reperfusion t=−2.237, p=0.030, HbA1c-not significant). Conclusions/implications Admission Glucose levels are associated with larger infarct size, and HbA1c levels are associated with reduced myocardial salvage. However, glycaemic status is not an independent predictor of infarct size or salvage when time to reperfusion is taken in to consideration.

Early Experience of the Use of Ringed PTFE Graft for Middle Hepatic Vein Reconstruction for Living Donor Liver Transplantation

Introduction: We present the initial experience of use of ringed PTFE graft for middle hepatic vein (MHV) reconstruction for living donor liver transplantation (LDLT) at Haeundae Paik hospital during two years from the hospital opening. Large vein allograft, especially cryopreserved vein, is suitable for MHV reconstruction, but its supply is often limited in a newly opened hospital. For this reason, ringed PTFE (GORE-TEX®) grafts (10-12 mm in diameter) were used to reconstruct MHV branches for the modified right lobe grafts in our institution. Method: From March 2010 to December 2011, 10 LDLTs and 1 deceased donor LT were performed at our hospital. There were 8 cases of modified right lobe graft (MRL) and 2 cases of dual grafts. 7 ringed PTFE grafts were used in 8 MRL. In one MRL, ringed PTFE did not need due to MHV branches were less than 5 mm in diameter. 6 of 7 cases were analyzed. One case was excluded because retransplantation was performed 3 weeks later of LDLT due to hepatic artery rupture. Results: The patency of the ringed PTFE graft was checked with computed tomography scan of the liver. The 1-month, 4-month and 6-month patency rates of the ringed PTFE grafts were 100% (6/6), 50% (3/6) and 16.6% (1/6) respectively. All showing late obstruction (over 4 months) were asymptomatic (no elevated liver enzyme) and did not have congestion of the liver on CT scans. There were no specific complications related using ringed PTFE graft and no patient death, chronic graft dysfunction or graft loss during follow up period. Conclusion: Although small cases, the early ringed PTFE graft function was excellent and late obstruction of ringed PTFE graft had no specific clinical problems on graft function or patient survival. Ringed PTFE graft seems to be a good alternative material for MHV reconstruction.

Endoscopic septostomy through a standard precoronal ventricular access: feasibility and effectiveness

Although endoscopic septostomy is widely adopted in the treatment of unilateral or specific types of hydrocephalus, there is no consensus on surgical indications, technical aspects and postoperative outcome. In particular, the choice of the ventricular access has been recently debated. We investigated the results of endoscopic septostomy performed through a standard precoronal ventricular access using a rigid endoscope. Patients who underwent an endoscopic septostomy at our Institution from March 2001 to March 2011 were retrospectively identified. Clinico-radiological data and video recordings of the endoscopic procedures were reviewed. Sixty-three patients (50 children and 13 adults) were collected. In adults, the obstruction of the cerebrospinal fluid (CSF) pathway was exclusively secondary to a tumor (neoplastic or pseudoneoplastic lesion). In the pediatric group hydrocephalus was most commonly due to a neoplasm (33 out of 50 patients), post-hemorrhagic and/or post-infectious hydrocephalus affecting 11 children and malformative hydrocephalus the remaining six children. We were able to perform the septostomy in all but two patients, presenting with a scarred multilayered septum secondary to post-hemorrhagic hydrocephalus. In 37 cases, one or more other endoscopic procedures were performed contemporarily. The mean follow-up was 24months (min-max: 5-96months). Overall, all but one patient benefited clinically and radiologically from the endoscopic septostomy. Two patients harboring a pineal/mesencephalic tumor experienced a late obstruction of the stoma secondary to neoplastic infiltration of the septum. Endoscopic septostomy can be safely performed through a standard burr-hole. The effectiveness of this approach is testified by an early success rate of more than 95% and a long term success rate of 92%.

17 URETEROCALICOSTOMY FOR THE TREATMENT OF SELECT CASES OF URETEROPELVIC JUNCTION OBSTRUCTION

INTRODUCTION AND OBJECTIVES: Hydronephrosis can be a serious complication of aortic reconstructive surgery, presenting in early or late postoperative period. The incidence and treatment tactics for this infrequent complication are still debated in literature. Our study tries to answer these questions. METHODS: 450 patients following aortofemoral and aortoiliac reconstruction were included. There were 382 (84.9%) males and 68 (15.1%) females with a median age of 65.7 8.3 years. Patients were investigated preoperatively and at 1 week, 3, 6 and 12 months after vascular surgery. Two urologists performed clinical and ultrasound examination, intravenous pyelograms assessment. Patients with preoperatively diagnosed urological pathology were not included into this study. RESULTS: We revealed unilateral hydronephrosis in 8.0% (36/ 450) of patients. 83.3% (30/36) of them had a history of aortic aneurysm resection with aortofemoral bypass grafting and 16.7% (6/36) underwent aortofemoral bypass only (p 0.05). There were 44.4% (16/36) patients with mild obstruction and 55.6% (20/36) patients with extensive ureteral strictures. The mild asymptomatic obstruction resolved spontaneously following 1 month of observation. Patients with late (6–12 months) obstruction developed ureteral strictures and required for active management. They underwent ureterolysis and ureteral resection with ureteroureterostomy. Four of them developed stricture relapse postoperatively. Intraureteral metallic self-expanding endoprosthesis placement was performed to eliminate the obstruction in 3 cases. One patient with obliteration of ureter underwent subcutaneus nephrovesical bypass. CONCLUSIONS: Ureteral obstruction can be a serious complication of reconstructive aortic surgery. This especially concerns to aneurysms of abdominal aorta and patients with graft complications. Early mild asymptomatic obstruction may resolve spontaneously or require ureteral stenting. Late hydronephrosis may contribute to retroperitoneal fibrosis associated with periureteral inflammatory process and extensive ureteral strictures. Intraureteral metallic self-expanding endoprosthesis or subcutaneus nephrovesical bypass placement can be appropriate in patients with contraindications to open reconstructive surgery.

Serial angiographic and intravascular ultrasound evaluation to interrogate the presence of late “catch-up” phenomenon after cypher® sirolimus-eluting stent implantation

Despite the expressive reduction in the intimal hyperplasia (IH) formation after DES implantation at the mid-term, late restenosis has been recently noticed. Our objective was to determine, by means of serial angiography (QCA) and intravascular ultrasound (IVUS) at two different time points, whether the occurrence of the "late catch-up" phenomenon occurs after sirolimus-eluting stent (SES) implantation. Thirty-eight non-complex patients treated with a single 18-mm SES who had systematic serial QCA and IVUS analyses at mean 8 and 20months were enrolled. Primary endpoint is to evaluate the temporal course of IH formation after SES implantation, by comparing QCA in-stent late loss and IVUS percent IH obstruction between the invasive follow-ups. Mean cohort age was 59.3years and 31.6% were diabetics. Baseline reference vessel diameter was 2.8 ± 0.4mm and lesion length was 11.5 ± 3.5mm. Left anterior descending artery was the most frequent target vessel (55.3%). Between 8 and 20months, a non-significant increase in in-stent late loss from 0.10 ± 0.18 to 0.15 ± 0.30mm (P=0.38) was observed. By IVUS, a slight increase in the percent IH obstruction (1.03 ± 2.13 to 1.76 ± 1.87%, P=0.12) was detected between the two evaluations. Interestingly, all the neoformed tissue accrued from 8 to 20months accumulated in the distal portion of the stent. In the non-complex scenario, SES implantation was associated with a minimal, non-significant increase in the IH volume between 8 and 20months.

Unobstructive Total Anomalous Pulmonary Venous Return: Impact of Early Elective Repair on the Need for Prolonged Mechanical Ventilatory Support

Optimal timing for elective repair of total anomalous pulmonary venous return (TAPVR) in the case of an unobstructed anomalous pathway is unclear. All infants with a diagnosis of TAPVR as an isolated lesion who underwent surgical repair at Children's Hospital of Wisconsin from 1991 to 2007 were reviewed to assess location of drainage, presence of obstruction, age at presentation, age at surgery, death, need for extracorporeal membrane oxygenation (ECMO), length of hospital stay, length of mechanical ventilation (MV), and late pulmonary venous obstruction. A total of 65 patients were identified: 38 (59%) with supracardiac drainage, 10 (15%) with cardiac drainage, 11 (17%) with infracardiac drainage, and 6 (9%) with mixed drainage. For 39 (60%) of the 65 patients, obstruction was identified preoperatively. Three early and five late deaths occurred after surgery (12%), all involving patients with preoperative obstruction. Most of the late deaths (80%) involved patients who experienced recurrent obstruction. Of the 65 patients, 26 (40%) had no obstruction preoperatively, and none died, required ECMO support, or experienced late obstruction. For the 26 patients without obstruction, the timing of surgery was elective at the discretion of the supervising cardiologist. Among these 26 patients, 15 had surgery less than 10days after presentation (median age, 18days), and 53% of these 15 patients (8/15) had MV less than 5days. In contrast, all 11 patients who had elective surgery more than 10days after presentation (median age, 56days) required MV for more than 5days (p=0.007). Isolated TAPVR appears to be at the highest risk for death and late postoperative obstruction when obstruction is present preoperatively. Patients with unobstructive TAPVR do very well, but potential morbidity related to prolonged MV appears to be significantly reduced by early elective surgery.

Anomalous pulmonary venous connection to superior vena cava: Warden technique

Repair of anomalous pulmonary venous connection (APVC) to superior vena cava (SVC) with internal pericardial patch may be complicated by the obstruction of the SVC or pulmonary veins and sinus node dysfunction. Moreover, the shrinkage of the pericardium may lead to late obstruction. Various techniques are practiced, which have reduced the incidence of obstruction to the venous drainage, but sinus node dysfunction continues to be an issue. We reviewed our experience with the Warden technique, predominantly in children, for various types of APVC to the SVC. Between 2006 and 2010, 32 patients with anomalous drainage of the pulmonary veins to SVC underwent repair by the Warden technique in our institute. The median age at operation was 4 years (range 3 months-34 years). Partial anomalous pulmonary venous connection (PAPVC) was present in 28 patients, while four patients had total anomalous pulmonary venous connection (TAPVC) to the SVC, where one or more pulmonary veins joined the SVC separately from the entry of the common chamber. Clinical data, echocardiography and operative details were collected from our database, retrospectively. At a median follow-up of 24 months, there was no mortality. One patient had transient rhythm disturbance. On follow-up, it was revealed that all patients are in sinus rhythm with no evidence of systemic or pulmonary venous obstruction. The Warden technique is a simple and effective surgical option, which should be preferred for patients with anomalous drainage of the pulmonary veins to SVC. Though arrhythmias are rare in the early follow-up, longer follow-up is required to rule out their late development.

Late obstruction of an endoscopic third ventriculostomy stoma by metastatic seeding of a recurrent medulloblastoma

Endoscopic third ventriculostomy (ETV) has been established as an effective method in the treatment of tumoral obstructive hydrocephalus. Delayed closure of the ETV stoma has been attributed to scarring involving the third ventricular floor. Secondary obstruction of the stoma due to intraventricular tumor seeding is an extremely rare condition, with only one case described to date. The authors report on a unique case of late closure of the ETV stoma caused by metastatic seeding of a recurrent medulloblastoma 9 years after the initial treatment. The patient was submitted to a second endoscopic procedure in which a reddish mass located just at the third ventricular floor was resected, leading to reopening of the previous ETV stoma. To the best of the authors' knowledge, this case is the first report of an ETV obstruction due to metastatic CSF seeding of a medulloblastoma. In such cases of late failure of the ETV stoma because of tumor obstruction, a second ETV can be safely performed and lead to adequate function of the stoma, even if limited by the aggressive nature of the disease.

Acute and late obstruction of a modified Blalock–Taussig shunt: a two-center experience in different catheter-based methods of treatment

Modified Blalock-Taussig (B-T) shunt occlusion results in a sudden reduction of pulmonary vascular perfusion, causing dramatic saturation drop and cyanosis which pose a direct hazard to a child's life. The results of percutaneous local r-tpa infusion, balloon angioplasty and additionally stent implantation in obstructed modified B-T shunts were studied to assess their role as an alternative to a re-do surgery. We outline two pediatric centers' experience (period 2004-2008) regarding the effectiveness of various emergency treatment methods for occlusion or critical stenosis of systemic-to-pulmonary arterial shunts in 23 children. Local r-tpa infusion via catheter was performed in 12/23 patients, balloon angioplasty in 22/23 and additionally stent implantation in 3/23 children. Procedures were successful in 22/23 patients (96%), with an increase in arterial saturation [average: 30%; standard deviation (S.D.) 15%; Shapiro-Wilk test; dependent t-test-P<0.01]. Unrestricted contrast flow was achieved in 18 patients, reduced central flow in three and minimal flow in one child. Neither local nor systemic complications occurred. Our experience demonstrates the possibility of successful early shunt recanalization with the use of local thrombolytic therapy combined with the balloon angioplasty. The presence of old fixed thrombus with neointimal hypertrophy in the shunt constitutes an indication for endovascular stent implantation.

Biventricular Repair of Atrioventricular Septal Defect With Common Atrioventricular Valve and Double-Outlet Right Ventricle

The combination of an atrioventricular septal defect with a common atrioventricular junction guarded by a common valve, and double-outlet right ventricle, is a rare lesion that presents a challenge for surgical repair. This report describes our surgical approach and results in 16 patients undergoing biventricular repair for such a combination of lesions. A retrospective analysis was performed for all patients undergoing biventricular repair of atrioventricular septal defect with common atrioventricular valve and double-outlet right ventricle between 1991 and 2008. Patients with tetralogy of Fallot and common atrioventricular valve were excluded from analysis. Early and actuarial outcomes were evaluated using the chi(2) test for categorical variables and Wilcoxon rank sum for ordinal variables. The median age at operation was 16 months. Heterotaxy syndrome was present in 12 of the 16 patients (9 right isomerism and 3 left isomerism), and 6 had concurrent totally anomalous pulmonary venous connections. Primary repair was achieved in 6 patients, and 10 underwent one or more prior operations (most frequently a shunt, banding of the pulmonary trunk, or repair of the anomalous pulmonary venous connections). Enlargement of the ventricular septal defect by resection of the muscular outlet septum was required in 11 patients, in whom the ventricular septal defect emptied entirely or primarily to the inlet of the right ventricle. A conduit was placed from the right ventricle to the pulmonary arteries in 13. There was 1 death before discharge from hospital, 1 late death, and 2 episodes of heart block. Among survivors, follow-up was complete with a median follow-up of 66 months. No patient had late obstruction of the left ventricular outflow tract. The presence of heterotaxy with totally anomalous pulmonary venous connections was associated with combined mortality and significant morbidity (p = 0.008). Although technically challenging, the surgical repair can be accomplished with acceptable early results. Heterotaxy syndrome, with concurrent anomalous connections of the pulmonary veins, represented the strongest identified risk factor for death or significant complication.

Repair of injured right inferior pulmonary vein during mitral valve replacement

During mitral valve surgery right pulmonary veins injury, subsequent to excessive traction (for better exposure of the mitral apparatus), is often unavoidable. This is more likely in patients with small left atrium. This common complication may cause severe intraoperative bleeding, while its surgical repair may lead to complications such as late stenosis or obstruction of the pulmonary veins. This injury should be early detected, before left atriotomy closing, and it is suggested to be repaired using a patch so as to avoid any possible late constriction.We describe a case -to our knowledge, the first reported in the literature- of intraoperatively injured right inferior pulmonary vein in a patient who underwent mitral valve replacement. As outlined we propose that the ostium of the right inferior pulmonary vein can be repaired by using autologous pericardial patch, incorporated in the completion of left atriotomy closure.

Amplatzer Septal Occluder Associated With Late Pulmonary Venous Obstruction Requiring Surgical Removal With Acquired Aorta to Left Atrial Fistula

The Amplatzer septal occluder is currently the preferred device for the transcatheter closure of secundum atrial septal defects. Multiple studies have shown that device complications with the Amplatzer occluder are rare and often acute in presentation. The investigators describe the first reported case of late obstruction of the right pulmonary veins with an Amplatzer septal occluder and, in the same patient, an unusual intraoperative finding of a noncoronary aortic sinus to left atrium fistula after device removal.

A 96-well flow cytometric screening assay for detecting in vitro phospholipidosis-induction in the drug discovery phase

Drug-induced phospholipidosis is caused by lysosomal accumulation of the drug, resulting in the disturbance of phospholipid degradation and a consequent excessive phospholipid accumulation. Depending on the type and number of tissues affected, phospholipidosis occurrence in test animals can raise safety issues, which may be critical for the risk assessment. Safety profiling of potential phospholipidosis-inducing drugs in the drug discovery phase can predict these late obstructions of drug development. For this purpose, a flow cytometric assay based on the difference in fluorescent phospholipid accumulation in a human monocyte cell line was initially established. Modifying the assay studying degradation of the fluorescent phospholipids instead of accumulation drastically improved sensitivity. By testing various phospholipidosis-inducers and negative compounds, it was found that the assay could detect the occurrence of phospholipidosis by a 2-fold difference in fluorescence compared to control cells, demonstrating the superior sensitivity of the novel approach. Implementation of a higher throughput 96-well flow cytometric set up did not affect the sensitivity of detection or the reproducibility of the assay. Based on an extended test set of reference compounds a profiling approach was introduced, by which we show we can rank our drug candidates according to their phospholipidosis-inducing potential.

Palliative stenting for late malignant gastric outlet obstruction

Palliative stenting for late malignant gastric outlet obstruction

Percutaneous Therapy of Ureteral Obstructions and Leak After Renal Transplantation: Long-Term Results

The purpose of this study was to evaluate the long-term outcome of percutaneous therapy of ureteral complications after renal transplantation. Between January 2000 and June 2006 we percutaneously treated 26 renal transplant patients with ureteral obstruction (n=19) and leak (n=7). Obstructions were classified as early (<2 months after transplantation) or late (>2 months). Patients with leak were treated with nephro-ureteral catheter placement and subsequent double-J stenting. Balloon dilatation, stent placement, and basket extraction were used to treat ureteral obstructions. Patients were followed with ultrasonography. No major procedure-related complication occurred. The mean follow-up time was 34.3 months (range: 6 to 74 months). Initial clinical success was achieved in all 19 patients with obstruction and 6 of 7 patients with leak. Four of 9 early obstructions and 4 of 10 late obstructions recurred during the follow-up. All recurrences were initially managed again with percutaneous methods, including cutting balloon technique and metallic stent placement. Although there was no recurrence in patients with successfully treated leak, stricture was seen at the previous leak site in two patients. These strictures were also successfully managed percutaneously. We conclude that in the treatment of ureteral obstruction and leak following renal transplantation, percutaneous therapy is an effective alternative to surgery. However, further interventions are usually needed to maintain long-term patency.

An artificial vascular graft is a useful interpositional material for drainage of the right anterior section in living donor liver transplantation

Congestion in the anterior section in a right liver (RL) without a middle hepatic vein (MHV) may lead to graft dysfunction. To solve this problem, an RL draining MHV branches with autologous or cryopreserved vessels can be introduced. However, these vessels are often unavailable, and their preparation is time-consuming. An expanded polytetrafluoroethylene (ePTFE) graft may be used for anterior section drainage. Between February and November 2005, 26 recipients underwent RL liver transplantation draining MHV branches with an ePTFE graft (group P). Twenty-six ePTFE grafts (6 or 7 mm in internal diameter) drained 35 MHV branches on the back table to the graft right hepatic vein or to the recipient's inferior vena cava. The patency of the ePTFE graft was checked with computed tomography scans of the liver. The outcome of group P was compared with those of an RL group with MHV (group M, n=17) and an RL group without reconstruction of MHV or its tributaries (group R, n=85). The 1-month and 4-month patency rates (PRs) of the ePTFE grafts were 80.8% (21/26) and 38.5% (10/26). All showing early obstruction of the ePTFE graft had congestion in the anterior section, but all showing late obstruction were asymptomatic. The 1-month PRs of group P were comparable to, but the 4-month PRs were lower than, those of group M (both 94.1%; P<0.05). However, 1-year patient and graft survival rates of group P (both 100%) were comparable to those of group M (94.1% and 100%) and better than those of group R (83.5% and 88.2%; P<0.05). In conclusion, the early PR of group P was good, and late obstruction of the ePTFE graft had no impact on congestion in the anterior section or patient survival. Therefore, an ePTFE graft may be a useful interposition material for anterior section drainage in RL transplantation without serious complications.

Late Obstruction after Subureteral Collagen Injection

We present a case with distal ureteral obstruction after a single subureteral collagen injection. Postnatally, the girl presented with bilateral vesicoureteral reflux (VUR). At one year of age, a bilateral subureteral collagen injection was carried out. Postoperatively, the girl was followed up regularly and showed no pathological findings. But three years later, hydronephrosis with a distal ureteral obstruction on the right side was found. An ureteral reimplantation was performed on that side and the histological finding was a ureteral stenosis, consisting of collagen with a knotty sclerosis and a histiocytic and granulomatous reaction. This is the first case with a late obstruction at the ureteral orifice three years after a single collagen injection. We found an inflammatory reaction against the collagen, which led to a sclerosis of the implant. Further surveillance of patients after subureteral injections should focus on this kind of complication.