Repair Of Obstruction Research Articles

Late outcomes after arterial switch operation for Taussig-Bing anomaly

To assess the long-term results of the arterial switch operation (ASO) for Taussig-Bing Anomaly (TBA) and identify risk factors affecting outcomes. Retrospective review and late follow-up was performed for all TBA patients from 1997 to 2010 (follow-up >3 years). Selection criteria included the absence of mitro-pulmonary continuity. Sixty-nine children underwent ASO at a median age of 24 days (interquartile range [IR] 11-125), with concomitant repair of aortic arch obstruction in 26 (37.7%). Complex coronary anatomy (n = 38; 55.0%) was common. Nine (13.0%) patients had staged repair. Hospital mortality was 5.8% (95% confidence interval [CI], 1.6%-14.2%; n = 4). Median follow-up was 11.2 years (IR 7.2-13.8). Subsequent mortality was confined to the first postoperative year (n = 5, 86% [95% CI, 78%-95%]), 1-, and 10-year survival). Overall mortality was related to coronary pattern (Yacoub types C and E vs A and D, multivariate, hazard ratio [HR] 12.2 [95% CI, 1.2-122.1], P = .03). At latest follow-up, 96% of the survivors are asymptomatic, with normal ventricular function. Cumulative incidence of reintervention at 10 years was 53% (95% CI, 28%-77%). Concomitant aortic arch obstruction was a predictor of reintervention (multivariate, HR 2.9 [95% CI, 1.1-7.4], P = .03). No mortality occurred upon reinterventions. In the largest series to date of ASO for TBA, mortality is confined to the first postoperative year, and related to coronary artery pattern. Beyond the first year, needed reinterventions are frequent, but with sustained functional status and no mortality over >10 years follow-up. Aortic arch obstruction is the main predictor for reintervention. Despite a significant rate of early events, favorable long-term outcomes argue for use of the ASO in TBA patients.

MO‐A‐9A‐01: Innovation in Medical Physics Practice: 3D Printing Applications

3D printing, also called additive manufacturing, has great potential to advance the field of medicine. Many medical uses have been exhibited from facial reconstruction to the repair of pulmonary obstructions. The strength of 3D printing is to quickly convert a 3D computer model into a physical object. Medical use of 3D models is already ubiquitous with technologies such as computed tomography and magnetic resonance imaging. Thus tailoring 3D printing technology to medical functions has the potential to impact patient care. This session will discuss applications to the field of Medical Physics. Topics discussed will include introduction to 3D printing methods as well as examples of real‐world uses of 3D printing spanning clinical and research practice in diagnostic imaging and radiation therapy. The session will also compare 3D printing to other manufacturing processes and discuss a variety of uses of 3D printing technology outside the field of Medical Physics.Learning Objectives: Understand the technologies available for 3D Printing Understand methods to generate 3D models Identify the benefits and drawbacks to rapid prototyping / 3D Printing Understand the potential issues related to clinical use of 3D Printing

Contemporary Results of Surgical Repair of Recurrent Aortic Arch Obstruction

There is a paucity of data on the current outcomes of surgical intervention for recurrent aortic arch obstruction (RAAO) after initial aortic arch repair in children. The goal of this study is to report the long-term results in these patients. All patients undergoing surgical intervention for RAAO at Texas Children's Hospital from 1995 to 2012 were included. The cohort was divided into four groups based on initial procedure: (1) simple coarctation repair, (2) Norwood procedure, (3) complex congenital heart disease, and (4) interrupted aortic arch. A total of 48 patients age 9 months (range, 22 days to 36 years) underwent 49 procedures for RAAO. All patients had an anatomic repair consisting of either patch aortoplasty (n=27, 55%), aortic arch advancement (n=8, 16%), sliding arch aortoplasty (n=6, 12%), placement of an interposition graft (n=2, 17%), reconstruction with donor allograft (n=4, 8%), extended end-to-end anastomosis (n=1, 2%), or redo Norwood-type reconstruction (n=1, 2%). Most procedures (n=46, 94%) were performed through a median sternotomy using cardiopulmonary bypass. At a median follow-up of 6.1 years (range, 9 days to 17 years), only 2 patients required surgical or catheter-based intervention for RAAO. Hypertension was present in 10% of patients at last follow-up. There were no neurologic or renal complications. There was 1 perioperative death after an aortic arch advancement in group 1. Four other patients have died during follow-up, none of the deaths related to RAAO. Anatomic repair of RAAO is a safe procedure associated with low morbidity and mortality, and low long-term reintervention rates.

Combined primary repair of right ventricular outflow tract obstruction and ascending aortic aneurysm

A 23-year-old male presented with dyspnoea, cyanosis and clubbing and diagnosed to have the right ventricular outflow tract obstruction, patent foramen ovale, severe aortic regurgitation and ascending aortic aneurysm. The diagnosis was achieved by transthoracic echocardiography, cardiac catheterization and contrast-enhanced computed tomography. A successful intracardiac repair with aortic root replacement was performed. Postoperative course was uneventful. Postoperative and 3-month follow-up echocardiogram revealed no gradient across right ventricular outflow tract with mild pulmonary regurgitation and normally functioning prosthetic aortic valve. Histological examination of the aorta revealed cystic medial necrosis of aneurysmal sac wall.

PD3-10 FISTULATION INTO THE PUBIC SYMPHYSIS FOLLOWING RADIOTHERAPY FOR PROSTATE CANCER - AN IMPORTANT AND SURGICALLY CORRECTABLE COMPLICATION

INTRODUCTION AND OBJECTIVES: Previous publications have reported on the role of ureteral reconstructive techniques for repair of ureteral defects from extirpative surgery for urologic malignancies or external trauma. Our institution has managed a large volume of ureteral obstruction and injuries from other sources such as iatrogenic injury during pelvic surgery and retroperitoneal fibrosis. We sought to review this experience, report on outcomes, and develop an algorithm for treatment. METHODS: We reviewed the charts of 139 patients that underwent ureteral reconstruction or endoscopic treatment of ureteral injury in an eleven-year period at a single institution by three surgeons (TTH, PJM, BJF). Data including mechanism of injury, type of repair, location of injury, length of stricture, comorbid factors, length of follow up, success rate, complications, and need for secondary procedures was obtained. Success rate was defined based on ureteral patency and stabilization or improvement of renal function. RESULTS: 115 patients met inclusion criteria, of which 18 were bilateral systems, for a total of 133 renal units. 24 patients were excluded due to primary repair for UPJ obstruction, active malignancy, or external traumatic injuries. Mechanism of injury included iatrogenic injury during pelvic surgery (50%), radiation-induced or idiopathic retroperitoneal fibrosis (26%), endoscopic stone surgery (4%), and other (20%). Location of the injury was proximal (22%), mid (36%), and distal ureter (42%). The average length of stricture was 5 cm. The type of repair included ureterolysis +/omentoplasty (n 1⁄4 17), ureteroureterostomy (n 1⁄4 5), ureteral reimplant +/psoas hitch (n 1⁄4 58), Boari Flap (n 1⁄4 2), TUU (n 1⁄4 3), ileal ureter (n 1⁄4 39). Our primary success rate was 93%, with 7% of patients undergoing a subsequent procedure. Of the 9 failures, 3 underwent successful secondary procedure for a total success rate of 95%. There were 11 major complications defined as a Clavien grade 3 or greater including bowel obstruction, enterocutaneous fistula, anastomotic dehiscence, boari flap necrosis, and one death within 90 days. Median length of follow up was 121 days. CONCLUSIONS: Ureteral reconstruction for benign stricture disease is highly successful. Most strictures can be resolved utilizing simple techniques such as ureteral reimplantation +/psoas hitch. Longer strictures, particularly those involving the proximal or mid ureter, often require complex techniques such as ileal-ureteral substitution.

Radical Vaginal Hysterectomy and Trachelectomy in Early-Stage Cervical Cancer

Objective: To communicate a minimally invasive technique for surgical handling of early-stage cervical cancer and its results. Methods: 110 patients with cervical cancer in stages IA2 and IB1, all of them operated in a period of 5 years in both hospitals, are presented. Laparoscopic systemic pelvic lymphadenectomy with radical vaginal hysterectomy or radical vaginal trachelectomy was performed to patients, with the exception of those patients who had compromised nodes detected in contemporary biopsy. Results: Between April 2008 and May 2013, 110 patients were submitted to this technique. 15 patients had their surgery aborted: 13 presented positive nodes for carcinoma in contemporary biopsy and 2 had extensive cervical compromise when performing radical vaginal hysterectomy or trachelectomy. Analysis of the remaining 95 cases shows an average age of 43.9 years (26 - 61), all of them had given birth before, 23 (21%) of them through C-section. BMI averaged 30.5 and 31 (28.2%) had cone surgery performed previously. Average duration of surgery was of 220 minutes. Postoperative hospitalization averaged 3.1 days. Bleeding volume was estimated at 125 cc and one patient required blood transfusion. En 25 patients’ uterine annexes were kept and all of them were suspended by means of laparoscopy. On average, 25.4 pelvic nodes were obtained. Complications 13.6% with eight patients suffered bladder injury, two had rectovaginal fistula, 3 patients requires surgical repair of ureteral obstruction, two patients present thromboembolic disease. The disease-free and overall survivals are consistent with reports in the literature. Conclusion: We believe that handling patients with this technique is possible and has the advantages of vaginal and laparoscopic surgery with minimal complications.

Minimally Invasive Pyeloplasty in Horseshoe Kidneys with Ureteropelvic Junction obstruction: A case series

Horseshoe kidney is an uncommon renal anomaly often associated with ureteropelvic junction (UPJ) obstruction. Advanced minimally invasive surgical (MIS) reconstructive techniques including laparoscopic and robotic surgery are now being utilized in this population. However, fewer than 30 cases of MIS UPJ reconstruction in horseshoe kidneys have been reported. We herein report our experience with these techniques in the largest series to date. We performed a retrospective chart review of nine patients with UPJ obstruction in horseshoe kidneys who underwent MIS repair at our institution between March 2000 and January 2012. Four underwent laparoscopic, two robotic, and one laparoendoscopic single-site (LESS) dismembered pyeloplasty. An additional two pediatric patients underwent robotic Hellstrom repair. Perioperative outcomes and treatment success were evaluated. Median patient age was 18 years (range 2.5-62 years). Median operative time was 136 minutes (range 109-230 min.) and there were no perioperative complications. After a median follow-up of 11 months, clinical (symptomatic) success was 100%, while radiographic success based on MAG-3 renogram was 78%. The two failures were defined by prolonged t1/2 drainage, but neither patient has required salvage therapy as they remain asymptomatic with stable differential renal function. MIS repair of UPJ obstruction in horseshoe kidneys is feasible and safe. Although excellent short-term clinical success is achieved, radiographic success may be lower than MIS pyeloplasty in heterotopic kidneys, possibly due to inherent differences in anatomy. Larger studies are needed to evaluate MIS pyeloplasty in this population.

Pediatric Standard and Robot-Assisted Laparoscopic Pyeloplasty: A Comparative Single Institution Study

We report our experience and compare the outcomes between standard and robot-assisted laparoscopic pyeloplasty to treat ureteropelvic junction obstruction in children. A retrospective cohort study was performed of all children who underwent standard or robot-assisted laparoscopic pyeloplasty for ureteropelvic junction obstruction at a single institution from October 2007 to January 2012. Indications for surgery included symptomatic obstruction and abnormal diuretic renal scan. A successful outcome was defined as resolution of clinical symptoms, improvement of hydronephrosis on ultrasound, stable ultrasound with resolution of symptoms or improvement of the drainage curve on diuretic renal scan. We reviewed 18 patients (median age 8.1 years) who underwent standard and 46 (8.8 years) who underwent robot-assisted laparoscopic pyeloplasty (p = 0.194). Median operative time was 298 minutes (range 145 to 387) for standard and 209 minutes (106 to 540) for robot-assisted laparoscopic pyeloplasty (p = 0.008). Mean hospitalization was similar between the groups (1 day for standard vs 2 days for robot-assisted laparoscopic pyeloplasty, p = 0.246). Narcotic use was similar between the groups. Median followup was 43 months for standard and 22 months for robot-assisted laparoscopic pyeloplasty (p <0.01). Renal ultrasound showed postoperative improvement of hydronephrosis in 85% and stable disease in 15% of patients following robot-assisted laparoscopic pyeloplasty, and improvement in 89.5% and stable disease in 10.5% after standard laparoscopic pyeloplasty. Symptoms resolved in 100% of patients (38 of 38) after robot-assisted laparoscopic pyeloplasty and 87.5% of patients (7 of 8) after standard laparoscopic pyeloplasty. Robot-assisted laparoscopic pyeloplasty and standard laparoscopic pyeloplasty are effective techniques to correct ureteropelvic junction obstruction, with similar outcomes. Robot-assisted laparoscopic pyeloplasty had a shorter operative time, and its success and complication rates are comparable to standard laparoscopic pyeloplasty.

Trends in the treatment of adults with ureteropelvic junction obstruction.

Minimally invasive pyeloplasty is an effective treatment for patients with ureteropelvic junction obstruction that offers quicker convalescence than open pyeloplasty. Technical challenges, however, may have limited its dissemination. We examined population trends and determinants of surgical options for ureteropelvic junction obstruction. Using the State Inpatient and Ambulatory Surgery Databases for Florida, we identified adults who underwent ureteropelvic junction obstruction repair between 2001 and 2009. After determining the surgical approach (minimally invasive pyeloplasty, open pyeloplasty, or endopyelotomy), we estimated annual utilization rates and the effects of patient, surgeon, and hospital predictors on surgery type, using multilevel multinomial logistic regression. Rates of minimally invasive pyeloplasty increased 360% (P for monotonic trend < 0.01), while rates of open pyeloplasty decreased 56% (P<0.01). Rates of endopyelotomy were substantially higher and remained relatively stable (P=0.27). Compared with open pyeloplasty, minimally invasive pyeloplasty was used more commonly among patients with private insurance (odds ratio [OR] 1.6; 95% confidence interval [CI], 1.2-2.3), those treated at teaching hospitals (OR 1.6; CI 1.0-2.6), and those treated by high-volume surgeons (OR 2.9; CI 2.0-4.2). Its use was less frequent among patients with multiple comorbidities (OR 0.53; CI 0.37-0.76). Similar associations were observed when comparing receipt of minimally invasive pyeloplasty with endopyelotomy; however, patients who underwent endopyelotomy were older. The use of minimally invasive pyeloplasty has dramatically increased, largely replacing open pyeloplasty, while the use of endopyelotomy, albeit significantly more common than the other approaches, has remained stable. The surgical approach is influenced by several patient, surgeon, and hospital factors.

Effects of nasal surgery on the upper airway: A drug‐induced sleep endoscopy study

To evaluate the impact of nasal surgery on the oropharyngeal and hypopharyngeal anatomy of patients with obstructive sleep apnea (OSA) by comparing drug-induced sleep endoscopy (DISE) data prior to and following nasal surgery. Retrospective review of medical records and DISE video recordings. Twenty-four patients with OSA were identified who underwent nasal surgery for symptomatic nasal obstruction. Clinic charts and DISE video recordings were reviewed. Preoperative and postoperative DISE recordings were compared to determine whether nasal surgery affected the level, degree, and sustainability of upper airway obstruction. Overall, the pattern of upper airway obstruction did not change significantly following nasal surgery (P > .05). Almost all patients demonstrated residual obstruction by postoperative DISE (96%), with no change in plans for surgical management of oropharyngeal and hypopharyngeal collapse (83%). Partial improvement in palatal collapse was present in a subset of patients without tongue base obstruction (P < .05). Postoperative apnea-hypopnea index decreased from a mean of 23.6 to 20.4 events/hr, but this change was not significant (P > .05). For most patients with OSA, surgical repair of nasal obstruction does not significantly improve oropharyngeal or hypopharyngeal collapse as seen on DISE. However, mild improvement in palatal collapse is seen in a subset of patients without tongue base obstruction. This study reveals that if DISE is being utilized to direct surgical management of OSA, it does not need to be repeated for most patients after nasal surgery.

Improving Left Ventricular Outflow Tract Obstruction Repair in Common Atrioventricular Canal Defects

Left ventricular outflow tract obstruction (LVOTO) is the second most frequent reason for reoperation after atrioventricular canal (AVC) defect repair. Limited data are available on the mechanisms of LVOTO, their treatment, and outcomes. Between 1998 and 2010, 56 consecutive children with AVC underwent 68 LVOTO procedures. The AVC was partial in 4, transitional in 9, and complete in 43. The LVOTO procedure was required in 21 patients at the primary AVC repair, and the initial LVOTO procedure in 35 patients was a late reoperation after AVC repair. During a mean follow-up of 50±41 months, 5 patients (24%) with LVOTO repair at AVC repair required a reoperation for LVOTO, and 7 patients (20%) whose initial LVOTO repair was a reoperation required a second reoperation for LVOTO repair. Overall freedom from LVOTO reoperation was 98.5% at 1 year, 92.5% at 3 years, 81% at 5 years, 72.2% at 7 years, and 52.5% at 10 and 12 years. The freedom from reoperation was neither significantly different between partial, transitional, and complete AVC (p=0.78) nor between timing of the LVOT procedure (p=0.49). Modified single-patch AVC repair was associated with a higher LVOTO reoperation rate (p=0.04). Neither the mechanisms leading to LVOTO nor the surgical techniques used were independent predictors of reoperation. LVOTO in AVC is a complex and multifactorial disease. Aggressive surgical repair has improved late outcomes; however, risk factors for reoperation and the ideal approach for repair remain to be defined.

Abstract No. 295: Endovascular reconstruction for chronic iliocaval thrombosis: 15-year results

Chronic IVC thrombosis responds poorly to conservative therapy and surgical intervention. We evaluated the results of endovascular repair for thrombotic inferior vena cava (IVC) and iliocaval obstruction to see if endovenous reconstruction is a safe, effective and durable treatment option.

Anatomic Repair of Recurrent Aortic Arch Obstruction

Children undergoing repair of aortic coarctation are at lifelong risk of developing recurrent aortic obstruction. Several surgical techniques have been described to address this challenging problem. Some centers have used extraanatomic aortic bypass techniques to avoid dissection on the previously operated field. We have favored a technique that relies on anatomic reconstruction. Although a repeat end-to-

Extra-anatomic Bypass Graft for Recurrent Aortic Arch Obstruction

Extra-anatomic Bypass Graft for Recurrent Aortic Arch Obstruction

Experimental observation of pathological changes in the tissues after injurious biliary stricture

Objective To explore the histopathological changes of bile duct,liver and local tissue for injurious biliary stricture(IBS). Method To observe the morphological and pathological changes of bile duct, local tissue and liver in different periods with dogs as the established animal model for IBS. Result Bile duct obstruction due to injury can expand the proximal bile duct up to 18.91 ±1.85 mm as the pressure goes up. Damage to local tissue triggers acute inflammation. In early injury phase (within 10 d), inflammatory cell infiltration and proliferation appears on the wall of the duct with increased mucosal edema as well as thickening of the biliary ductile wall. In the late injury phase (15 d), the degree of infiltration of inflammatory cells, edema and mucosal thickness were reduced whereas fibroblast and collagen tissue were proliferated extensively. The wall of biliary duct also becomes fibrotic and thickens. Quantitative analysis of the inflammatory edema shows the most severe outcome on the 5th day (HE staining WBC count of 54.2±5.8 unit) and its severity progressively subsides on the 15th day. (HE staining WBC count of 41.7±7.2 vs 54.2±5.8 a, P＜0.0,5). In the early obstruction (5 d and 10 d), the liver cells showed mild to moderate swelling and its degeneration is often associated with steatosis and sinusoidal expansion and congestion. As the obstruction time increases in the 20 d and 30 d group, liver cells starts to show extensive vacuolation and sinusoidal occlusion. Conclusions Early phase (5 days) of acute bile duct obstruction due to injury shows rapid expansion of the bile duct, edema in the bile duct itself as well as its surrounding tissue and liver damage. After 15 days, the local inflammatory edema is greatly reduced and is replaced by hyperplasia of fibers and collagen. Liver damage appears to be irreversible after 20 days. Considering local environmental and systemic conditions, the optimal time frame to repair obstruction of bile duct surgically is between 10-20 days. Key words: Obstructive jaundice; Bile duct injury; Surgery; Opportunity; Pathology

Early Postoperative Severity of Illness Predicts Outcomes After the Stage I Norwood Procedure

We hypothesize that a measure of the immediate postoperative severity of illness after the stage I Norwood operation reflects technical performance or the adequacy of anatomic repair and can serve as a predictor of hospital mortality, reinterventions, and clinical outcomes. One hundred thirty-five patients undergoing stage I were retrospectively studied (2004 to 2007). The severity of illness on postoperative day 1 (POD1) was measured using the Pediatric Risk of Mortality III (PRISM) scoring system. Technical performance scores (optimal, adequate, inadequate) were calculated before hospital discharge. Hospital mortality, postoperative reinterventions, and complications were recorded. Postoperative reintervention was defined as need for cardiac catheterization laboratory or operating room based procedure that included balloon dilation or repair of arch obstruction, shunt revision, reoperations for bleeding, and extracorporeal membrane oxygenation support. Hospital mortality was 14.1% (n=19). The rate of complications and reinterventions was, respectively, 28.1% (n=38) and 26.7% (n=36). The POD1 PRISM score was associated with technical performance (p=0.003). Higher POD1 PRISM scores were associated with mortality (p<0.001), complications (p<0.001), and reinterventions (p=0.001). The POD1 PRISM score had high discrimination for mortality, complications, reinterventions, and inadequate technical performance (areas under the receiver operating characteristic curve were 0.835, 0.776, 0.773, and 0.710, respectively; p≤0.001 for all). The severity of illness as measured by PRISM score on POD1 after the stage I Norwood operation has strong association and discrimination with hospital mortality, postoperative reinterventions, inadequate technical performance, and major postoperative complications. It may be used as an early surrogate of technical performance to initiate a search for and correction of technical deficiencies.

Ascending Sliding Arch Aortoplasty: A Novel Technique for Repair of Arch Hypoplasia

Coarctation of the aorta (CoA) is often associated with clinically significant hypoplasia of the aortic arch. Historically, patch aortoplasty or bypass procedures have been the preferred techniques when arch augmentation is required in children beyond infancy. While safe and effective, these approaches require prosthetic or biologic material without the potential for growth, or normal endothelial and physiologic elastic function. This retrospective study reviews the use of a novel technique, ascending sliding arch aortoplasty, that utilizes viable autologous tissue for repair of arch obstruction in children beyond infancy. Between April 2002 and January 2007, 8 patients ranging in age from 18 months to 15 years underwent repair of CoA with arch hypoplasia using ascending sliding arch aortoplasty. All patients were approached through median sternotomy, utilizing cardiopulmonary bypass and selective antegrade cerebral perfusion. There was no mortality or major morbidity. One toddler had pneumonia, resulting in an increased length of stay. Median duration of hospitalization was 5.8 days, ranging from 3 to 10 days. No patient had evidence of residual obstruction or recurrent CoA at a mean follow-up interval of 36 months. Ascending sliding arch aortoplasty for CoA with arch obstruction in children beyond infancy is a safe technique that can be accomplished without deep hypothermic circulatory arrest. There is no evidence of recurrence at midterm follow-up. Because the augmentation is accomplished with viable autologous aortic tissue, the potential for growth, preserved elasticity and endothelial function, and resistance to infection make this method attractive for use in the young.

Complications rates of non-oncologic urologic procedures in population-based data: a comparison to published series

Published single institutional case series are often performed by one or more surgeons with considerable expertise in specific procedures. The reported incidence of complications in these series may not accurately reflect community-based practice. We sought to compare complication and mortality rates following urologic procedures derived from population-based data to those of published single-institutional case series. In-hospital mortality and complications of common urologic procedures (percutaneous nephrostomy, ureteropelvic junction obstruction repair, ureteroneocystostomy, urethral repair, artificial urethral sphincter implantation, urethral suspension, transurethral resection of the prostate, and penile prosthesis implantation) reported in the U.S.'s National Inpatient Sample of the Healthcare Cost and Utilization Project were identified. Rates were then compared to those of published single-institution series using statistical analysis. For 7 of the 8 procedures examined, there was no significant difference in rates of complication or mortality between published studies and our population-based data. However, for percutaneous nephrostomy, two published single-center series had significantly lower mortality rates (p < 0.001). The overall rate of complications in the population-based data was higher than published single or select multi-institutional data for percutaneous nephrostomy performed for urinary obstruction (p < 0.001). If one assumes that administrative data does not suffer from under reporting of complications then for some common urological procedures, complication rates between population-based data and published case series seem comparable. Endorsement of mandatory collection of clinical outcomes is likely the best way to appropriately counsel patients about the risks of these common urologic procedures.

Long-term Outcome and Risk of Heart Block After Surgical Treatment of Subaortic Stenosis

Although mortality following repair of subaortic obstruction is low, aggressive resection may increase morbidity. We sought to evaluate outcomes and risk of atrioventricular heart block (AVB) after subaortic resection in the current era. Simple obstruction was defined as a discrete subaortic membrane and complex as multilevel or diffuse narrowing. Limited resection included membranectomy and limited myomectomy. Aggressive resection included Konno, modified Konno, and Ross. Specified variables were obtained from a chart review. The 185 consecutive patients (1991-2008) ranged in age from 1 day to 21.8 years (5.1 ± 5.1 years) with 2 early and 4 late deaths. Actuarial survival was 97%, 95%, and 95% at 1, 5, and 10 years, respectively. Reoperations were required in 29 of 185 patients (15.7%); 2 required a third operation (1%). Freedom from reoperation in all patients was 97%, 83%, and 73% at 1, 5, and 10 years, respectively. Accessory mitral valve tissue (P < .001) and age <3 months (P = .004) predicted the need for reoperation. Transient or permanent high-degree AVB was documented in 33 of 185 patients (17.8%). Complex anatomy (P = .01) and aggressive resection (P < .001) increased the risk of acquiring AVB. The AVB was permanent in 21 of 185 (11.4%) patients, and pacemaker implantation was undertaken in 20 of 185 (10.8%) patients. Complex anatomy (P = .04) and modified Konno procedure (P = .03) increased the risk of acquiring a pacemaker. Aggressive resection lowered the frequency of recurrence but increased the risk of AVB. When aggressive resection is considered for long-term relief of subaortic obstruction, the risk of reobstruction must be balanced with the risk of AVB and the need for pacemaker implantation.

Lymphangiogenesis-independent resolution of experimental edema.

Vascular endothelial growth factor (VEGF)-C is necessary for lymphangiogenesis, and excess VEGF-C has been shown to be ameliorative for edema produced by lymphatic obstruction in experimental models. However, it has recently been shown that edema can resolve in the mouse tail even in the complete absence of capillary lymphangiogenesis when distal lymph fluid crosses the regenerating wound site interstitially. This finding has raised questions about the action of VEGF-C/VEGF receptor (VEGFR) signaling during the resolution of experimental edema. Here, the roles of VEGFR-2 and VEGFR-3 signaling in edema resolution were explored. It was found that edema resolved following neutralization of either VEGFR-2 or VEGFR-3 in the mouse tail skin, which inhibited lymphangiogenesis. Neutralization of either VEGFR-2 or VEGFR-3 reduced angiogenesis at the site of obstruction at day 10 (9.2 +/- 1.2% and 11.5 +/- 1.0% blood capillary coverage, respectively) relative to controls (14.3 +/- 1.5% blood capillary coverage). Combined VEGFR-2/-3 neutralization more strongly inhibited angiogenesis (6.9 +/- 1.5% blood capillary coverage), leading to a reduced wound repair of the lymphatic obstruction and extended edema in the tail skin. In contrast, improved tissue repair of the obstruction site increased edema resolution. Macrophages in the swollen tissue were excluded as contributing factors in the VEGFR-dependent extended edema. These results support a role for VEGFR-2/-3-combined signaling in the resolution of experimental edema that is lymphangiogenesis independent.