Biomechanical comparison of open Bankart repair vs. conjoint tendon transfer in a 10% anterior glenoid bone loss shoulder instability model.

BACKGROUND: The treatment of shoulder instability in patients with subcritical glenoid bone loss poses a difficult problem for surgeons as new evidence supports a higher failure rate when a standard arthroscopic Bankart repair is used. The purpose of this study was to compare a conjoint tendon transfer (soft-tissue Bristow) to an open Bankart repair in a cadaveric instability model of 10% glenoid bone loss. METHODS: Eight cadaveric shoulders were tested using a custom testing system that allows for a 6-degree-of-freedom positioning of the glenohumeral joint. The rotator cuff muscles were loaded to simulate physiologic muscle conditions. Four conditions were tested: (1) intact, (2) Bankart lesion with 10% bone loss, (3) conjoint tendon transfer, and (4) open Bankart repair. Range of motion, glenohumeral kinematics, and anterior-inferior translation at 60° of external rotation with 20 N, 30 N, and 40 N were measured in the scapular and coronal planes. Glenohumeral joint translational stiffness was calculated as the linear fit of the translational force-displacement curve. Force to anterior-inferior dislocation was also measured in the coronal plane. Repeated measures analysis of variance with a Bonferroni correction was used for statistical analysis. RESULTS: A Bankart lesion with 10% bone loss increased the range of motion in both the scapular (P = .001) and coronal planes (P = .001). The conjoint tendon transfer had a minimal effect on the range of motion (vs. intact P = .019, .002), but the Bankart repair decreased the range of motion to intact (P = .9, .4). There was a significant decrease in glenohumeral joint translational stiffness for the Bankart lesion compared with intact in the coronal plane (P = .021). The conjoint tendon transfer significantly increased stiffness in the scapular plane (P = .034), and the Bankart repair increased stiffness in the coronal plane (P = .037) compared with the Bankart lesion. The conjoint tendon transfer shifted the humeral head posteriorly at 60° and 90° of external rotation in the scapular plane. The Bankart repair shifted the head posteriorly in maximum external rotation in the coronal plane. There was no significant difference in force to dislocation between the Bankart repair (75.8 ± 6.6 N) and the conjoint tendon transfer (66.5 ± 4.4 N) (P = .151). CONCLUSION: In the setting of subcritical bone loss, both the open Bankart repair and conjoint tendon transfer are biomechanically viable options for the treatment of anterior shoulder instability; further studies are needed to extrapolate these data to the clinical setting.

Acute Hemodynamics in the Fontan Circulation: Open-Label Study of Vasopressin.

OBJECTIVE: To describe the acute hemodynamic effect of vasopressin on the Fontan circulation, including systemic and pulmonary pressures and resistances, left atrial pressure, and cardiac index. DESIGN: Prospective, open-label, nonrandomized study (NCT04463394). SETTING: Cardiac catheterization laboratory at Lucile Packard Children's Hospital, Stanford. PATIENTS: Patients 3-50 years old with a Fontan circulation who were referred to the cardiac catheterization laboratory for hemodynamic assessment and/or intervention. INTERVENTIONS: A 0.03 U/kg IV (maximum dose 1 unit) bolus of vasopressin was administered over 5 minutes, followed by a maintenance infusion of 0.3 mU/kg/min (maximum dose 0.03 U/min). MEASUREMENTS AND MAIN RESULTS: Comprehensive cardiac catheterization measurements before and after vasopressin administration. Measurements included pulmonary artery, atrial, and systemic arterial pressures, oxygen saturations, and systemic and pulmonary flows and resistances. There were 28 patients studied. Median age was 13.5 (9.1, 17) years, and 16 (57%) patients had a single or dominant right ventricle. Following vasopressin administration, systolic blood pressure and systemic vascular resistance (SVR) increased by 17.5 (13.0, 22.8) mm Hg ( Z value -4.6, p < 0.001) and 3.8 (1.8, 7.5) Wood Units ( Z value -4.6, p < 0.001), respectively. The pulmonary vascular resistance (PVR) decreased by 0.4 ± 0.4 WU ( t statistic 6.2, p < 0.001), and the left atrial pressure increased by 1.0 (0.0, 2.0) mm Hg ( Z value -3.5, p < 0.001). The PVR:SVR decreased by 0.04 ± 0.03 ( t statistic 8.1, p < 0.001). Neither the pulmonary artery pressure (median difference 0.0 [-1.0, 1.0], Z value -0.4, p = 0.69) nor cardiac index (0.1 ± 0.3, t statistic -1.4, p = 0.18) changed significantly. There were no adverse events. CONCLUSIONS: In Fontan patients undergoing cardiac catheterization, vasopressin administration resulted in a significant increase in systolic blood pressure, SVR, and left atrial pressure, decrease in PVR, and no change in cardiac index or pulmonary artery pressure. These findings suggest that in Fontan patients vasopressin may be an option for treating systemic hypotension during sedation or general anesthesia.

Superior Capsule Reconstruction With Fascia Lata Allograft Has Initial Stiffness and Ultimate Load Comparable to the Native Shoulder Superior Capsule: A Cadaveric Biomechanical Study.

PURPOSE: The purpose of this study was to compare the biomechanical characteristics of a fascia lata superior capsule reconstruction (FL-SCR) to the native superior capsule. METHODS: The native superior capsule of 8 cadaveric shoulders was tested with cyclic loading from 10 to 50 N for 30 cycles in 20° of glenohumeral abduction followed by load to failure at 60 mm/min. Following native superior capsule testing, FL-SCR was performed, which was tested as described for the native capsule. Paired t test was used for statistical analyses with P < .05 for significance. RESULTS: The stiffness for cycle 1 to 50 N was significantly higher for the native superior capsule compared to the FL-SCR (P = .001). By cycle 30, the stiffness between the two was not statistically different (P = .734). During load to failure, the initial stiffness to 2 mm for the FL-SCR and the native superior capsule was not statistically different (P = .262). The linear stiffness and yield load of the native superior capsule were significantly greater than that of the FL-SCR (94.5 vs 28.0 N/mm, P = .013; 386.9 vs 123.8 N, P = .029). There was no significant difference in ultimate load between the native superior capsule and the FL-SCR (444.9 vs 369.0 N, P = .413). CONCLUSIONS: FL-SCR has initial stiffness and ultimate load similar to the native superior capsule. CLINICAL RELEVANCE: The biomechanical properties of FL allograft make it an appealing option as a graft choice for superior capsule reconstruction.

Prediction Model with External Validation for Early Detection of Postoperative Pediatric Chylothorax.

Earlier diagnosis of chylothorax following pediatric cardiac surgery is associated with decreased duration of chylothorax. Pleural fluid testing is used to diagnosis chylothorax which may delay detection in patients who are not enterally fed at time of chylothorax onset. Our aim was to develop and externally validate a prediction model to detect chylothorax earlier than pleural fluid testing in pediatric patients following cardiac surgery. A multivariable logistic regression model was developed to detect chylothorax using a stepwise approach. The model was developed using data from patients < 18 years following cardiac surgery from Primary Children's Hospital, a tertiary-care academic center, between 2017 and 2020. External validation used a contemporary cohort (n = 171) from Lucille Packard Children's Hospital. A total of 763 encounters (735 patients) were analyzed, of which 72 had chylothorax. The final variables selected were chest tube output (CTO) the day after sternal closure (dichotomized at 15.6 mL/kg/day, and as a continuous variable) and delayed sternal closure. The highest odds of chylothorax were associated with CTO on post-sternal closure day 1 > 15.6 mL/kg/day (odds ratio 11.3, 95% CI 6,3, 21.3). The c-statistic for the internal and external validation datasets using the dichotomized CTO variable were 0.78 (95% CI 0.73, 0.82) and 0.84 (95% CI, 0.78, 0.9) and performance improved when using CTO as a continuous variable (OR 0.84, CI: 95% CI 0.80, 0.87). Using the models described, chylothorax after pediatric cardiac surgery may be detected earlier and without reliance on enteral feeds.

Current practices for refractory chylothorax following congenital heart surgery.

INTRODUCTION: Chylothorax following paediatric cardiac surgery is associated with significant morbidity, particularly those that are refractory to conservative therapy. It is our impression that there is important variability in the medical, surgical, and interventional therapies used to manage refractory chylothorax between congenital heart programmes. We therefore conducted a survey study of current practices for managing refractory chylothorax. METHODS: The Chylothorax Work Group, formed with the support of the Pediatric Cardiac Critical Care Consortium, designed this multi-centre survey study with a focus on the timing and indication for utilising known therapies for refractory chylothorax. The survey was sent to one chylothorax expert from each Work Group centre, and results were summarised and reported as the frequency of given responses. RESULTS: Of the 20 centres invited to participate, 17 (85%) submitted complete responses. Octreotide (13/17, 76%) and sildenafil (8/17, 47%) were the most utilised medications. Presently, 9 (53%) centres perform pleurodesis, 15 (88%) perform surgical thoracic duct ligation, 8 (47%) perform percutaneous lymphatic interventions, 6 (35%) utilise thoracic duct decompression procedures, and 3 (18%) perform pleuroperitoneal shunts. Diagnostic lymphatic imaging is performed prior to surgical thoracic duct ligation in only 7 of the 15 (47%) centres that perform the procedure. Respondents identified barriers to referring and transporting patients to centres with expertise in lymphatic interventions. CONCLUSIONS: There is variability in the treatment of refractory post-operative chylothorax across a large group of academic heart centres. Few surveyed heart centres have replaced surgical thoracic duct ligation or pleurodesis with image-guided selective lymphatic interventions.

2022 Bernard Morrey Award: the elbow ulnar collateral ligament complex demonstrates region specific stretching and recovery characteristics with valgus loading.

BACKGROUND: The objective of this study was to quantify the valgus laxity and strain of the elbow ulnar collateral ligament (UCL) complex after repeated valgus stretching and subsequent recovery. Understanding these changes may have important implications in improving strategies for injury prevention and treatment. The hypothesis was that the UCL complex will demonstrate a permanent increase in valgus laxity and region-specific increase in strain as well as region-specific recovery characteristics. METHODS: Ten cadaveric elbows (7M, 3F, 61.7 ± 2.7 years) were used. Valgus angle and strain of the anterior and posterior bands of the anterior bundle and the posterior bundle were measured at 1 Nm, 2.5 Nm, 5 Nm, 7.5 Nm, and 10 Nm of valgus torque at 70° of flexion for: (1) intact UCL, (2) stretched UCL, and (3) rested UCL. To stretch the UCL, elbows were cycled with increasing valgus torque at 70° of flexion (10 Nm-20 Nm in 1 Nm increments) until the valgus angle increased 8° from the intact valgus angle measured at 1Nm. This position was held for 30 minutes. Specimens were then unloaded and rested for 2 hours. Linear mixed effects model with Tukey's post hoc test was used for statistical analysis. RESULTS: Stretching significantly increased valgus angle compared to the intact condition 3.2° ± 0.2° (P < .001). Strains of both the anterior and posterior bands of the anterior bundle were significantly increased from intact by 2.8% ± 0.9% (P = .015) and 3.1% ± 0.9% (P = .018), respectively at 10 Nm. Strain in the distal segment of the anterior band was significantly higher than the proximal segment with loads of 5 Nm and higher (P < .030). After resting, the valgus angle significantly decreased from the stretched condition by 1.0° ± 0.1° (P < .001) but failed to recover to intact levels (P < .004). After resting, the posterior band had a significantly increased strain compared to the intact state of 2.6% ± 1.4% (P = .049) while the anterior band was not significantly different from intact. CONCLUSION: After repeated valgus loading and subsequent resting, the UCL complex demonstrated permanent stretching with some recovery but not to intact levels. The anterior band demonstrated increased strain in the distal segment compared to the proximal segment with valgus loading. The anterior band was able to recover to strain levels similar to intact after resting, while the posterior band did not.

Latissimus dorsi and teres major tendon transfer for irreparable anterosuperior rotator cuff tear improves kinematics and internal rotation compared to latissimus dorsi tendon transfer.

INTRODUCTION: Latissimus dorsi and teres major (LDTM) tendon transfer has demonstrated better clinical outcomes compared to Latissimus dorsi (LD) transfer for irreparable anterosuperior cuff (subscapularis/supraspinatus) tears; however, the biomechanical effects of these procedures are unknown. Therefore, the objective of this study was to compare kinematics and internal rotation of LDTM transfer to LD transfer for anterosuperior cuff tear. METHODS: Eight cadaveric shoulders were tested in four conditions; (1) intact, (2) anterosuperior rotator cuff tear, (3) LDTM transfer, and (4) LD transfer. Glenohumeral kinematics and internal rotation at 0°, 30°, and 60° of glenohumeral abduction in the scapular plane were measured. Muscle loading was applied based on physiological cross-sectional area ratios with three muscle loading conditions to simulate potentially increased tension due to the advanced insertion site of the transferred tendons. RESULTS: The anterosuperior rotator cuff tear leads to a significant superior shift of the humeral head compared to intact at 0° and 30° abduction (p < 0.039). Both the LDTM (p < 0.047) and LD transfers (p < 0.032) significantly shifted the humeral head inferiorly compared to the tear condition.; however, the LDTM transfer shifted the head in the anteroinferior direction compared to the LD transfer at 60° abduction and 30° ER (p < 0.045). Both LDTM and LD transfer significantly increased internal resting rotation (p < 0.008) and maximum internal rotation (p < 0.008) compared to anterosuperior rotator cuff tear and intact at 30° and 60° abduction. LDTM transfer resulted in a significant internal resting rotation compared with the LD transfer at 30° abduction with double muscle loading (p = 0.02). At 0° abduction, the LDTM transfer (p < 0.027) significantly increased maximum internal rotation compared to anterosuperior rotator cuff tear and intact. CONCLUSION: Although both LDTM and LD tendon transfer improved the abnormal humeral head apex position and internal rotation compared with the tear condition, the LDTM transfer was biomechanically superior to the LD transfer in a cadaveric model.

Comprehensive diagnostic catheterization in children with major aortopulmonary collateral arteries: A review of catheterization technique and anatomic nomenclature.

Achieving an optimal surgical result in patients with major aortopulmonary collateral arteries (MAPCAs) requires a thorough preoperative evaluation of the anatomy and physiology of the pulmonary circulation. This review provides a detailed description of diagnostic catheterization in patients with MAPCAs, including a summary of catheterization techniques, an overview of commonly used terms, and a review of MAPCA and pulmonary artery angiographic anatomy.

Biomechanical Assessment of a V-Shaped Semitendinosus Allograft Anterior Cable Reconstruction for Irreparable Rotator Cuff Tears.

PURPOSE: The purpose of this study was to biomechanically assess superior stability, subacromial contact pressures, and glenohumeral kinematics of a V-shaped anterior cable reconstruction with semitendinosus allograft (VST) in a massive rotator cuff tear (MCT) model. METHODS: Eight cadaveric shoulders (mean age, 66 years; range, 48 to 72 years) were tested with a custom testing system used to evaluate superior translation, subacromial contact pressure, and glenohumeral kinematics at 0°, 20°, and 40° glenohumeral abduction and 0°, 30°, 60°, and 90° of external rotation (ER). Conditions tested included (1) native state, (2) MCT (complete supraspinatus and ½ infraspinatus), a (3) VST. The VST was secured medially on the glenoid with 1 anchor and on the greater tuberosity with a double-row configuration using 4 anchors. RESULTS: The VST significantly decreased superior translation compared to the MCT at 0° and 20° glenohumeral abduction for 0°, 30°, and 60° humeral rotation and at 40° abduction and 0° degrees humeral rotation (P < .05). Superior translation following the VST remained significantly greater than the intact state at 0° abduction and 60° and 90° ER (P = .039 and 0.007, respectively) and 20° abduction and 30°, 60°, and 90° ER (P = .048, .003, and .004, respectively). The VST restored peak subacromial contact pressure to intact levels for all positions except 40° abduction and 60° ER. The VST did not statistically affect humeral head kinematics compared to the intact condition. CONCLUSIONS: In a biomechanical model, a VST anterior cable reconstruction partially restores superior stability and reduces peak subacromial contact pressure associated with an MCT, without affecting glenohumeral kinematics. The technique may be a consideration in the treatment of an irreparable MCT with isolated anterior cable disruption. CLINICAL RELEVANCE: The VST may provide an option for treatment of irreparable MCTs with anterior rotator cable disruption.

Human Dermal Allograft Superior Capsule Reconstruction With Graft Length Determined at Glenohumeral Abduction Angles of 20° and 40° Decreases Joint Translation and Subacromial Pressure Without Compromising Range of Motion: A Cadaveric Biomechanical Study.

PURPOSE: To compare the biomechanical effects of superior capsule reconstruction (SCR) graft fixation length determined at 20° and 40° of glenohumeral (GH) abduction. METHODS: Humeral translation, rotational range of motion (ROM), and subacromial contact pressure were quantified at 0°, 30°, and 60° of GH abduction in the scapular plane in 6 cadaveric shoulders for the following states: intact, massive rotator cuff tear, SCR with dermal allograft fixed at 20° of GH abduction (SCR 20), and SCR with dermal allograft fixed at 40° of GH abduction (SCR 40). Statistical analysis was conducted using a repeated-measures analysis of variance and a paired t test (P < .05). RESULTS: A massive cuff tear significantly increased total ROM compared with the intact state at 0° and 60° of abduction. SCR 20 or SCR 40 did not affect ROM. Compared with the intact state, the massive cuff tear model significantly increased superior translation by an average of 4.6 ± 0.5 mm in 9 of 12 positions (P ≤ .002). Both SCR 20 and SCR 40 reduced superior translation compared with the massive cuff tear model (P < .05); however, SCR 40 significantly decreased superior translation compared with SCR 20 at 0° of abduction (P ≤ .046). Peak subacromial pressure for the massive cuff tear model increased by an average of 486.8 ± 233.9 kPa relative to the intact state in 5 of 12 positions (P ≤ .037). SCR 20 reduced peak subacromial pressure in 2 of 12 positions (P ≤ .012), whereas SCR 40 achieved this in 6 of 12 positions (P ≤ .024). CONCLUSIONS: SCR with dermal allograft fixed at 20° or 40° of GH abduction decreases GH translation and subacromial pressure without decreasing ROM. CLINICAL RELEVANCE: With an increasing abduction angle for graft fixation, the medial-to-lateral graft length is decreased and the graft tension is effectively increased. Surgeons may increase shoulder stability without restricting ROM by fixing the graft at higher abduction angles. However, surgeons should remain cognizant of potential graft failure due to increased tension.

Anterior Cable Reconstruction of the Superior Capsule Using Semitendinosus Allograft for Large Rotator Cuff Defects Limits Superior Migration and Subacromial Contact Without Inhibiting Range of Motion: A Biomechanical Analysis.

PURPOSE: To biomechanically assess translation, contact pressures, and range of motion for anterior cable reconstruction (ACR) using hamstring allograft for large to massive rotator cuff tears. METHODS: Eight cadaveric shoulders (mean age, 68 years) were tested with a custom testing system. Range of motion (ROM), superior translation of the humeral head, and subacromial contact pressure were measured at 0°, 30°, 60°, and 90° of external rotation (ER) with 0°, 20°, and 40° of glenohumeral abduction. Three conditions were tested: intact, stage III tear (supraspinatus + anterior half of infraspinatus), and stage III tear + allograft ACR (involving 2 supraglenoid anchors for semitendinosus tendon allograft fixation. Allograft ACR included loop-around fixation using 3 side-to-side sutures and an anchor at the articular margin to restore capsular anatomy along the anterior edge of the cuff defect. RESULTS: ACR with allograft for stage III tears showed significantly higher total ROM compared with intact at all angles (P ≤ .028). Augmentation significantly decreased superior translation for stage III tears at 0°, 30°, and 60° ER for both 0° and 20° abduction, and at 0° and 30° ER for 40° abduction (P ≤ .043). Augmentation for stage III tears significantly reduced overall subacromial contact pressure at 30° ER with 0° and 40° abduction, and at 60° ER with 0° and 20° abduction (P ≤ .016). CONCLUSION: Anterior cable reconstruction using cord-like allograft semitendinosus tendon can biomechanically improve superior migration and subacromial contact pressure (primarily in the lower combined abduction and rotation positions), without limiting range of motion for large rotator cuff tendon defects or tears. CLINICAL RELEVANCE: In patients with superior glenohumeral instability, using hamstring allograft for ACR may improve rotator cuff tendon defect longevity by providing basic static ligamentous support to the dynamic tendon while helping to limit superior migration, without restricting glenohumeral kinematics.

Biomechanics of tensor fascia lata allograft for superior capsular reconstruction.

BACKGROUND: We hypothesized that in a cadaveric massive rotator cuff tear (MCT) model, a fascia lata (FL) allograft superior capsular reconstruction (SCR) would restore subacromial contact pressure and humeral head superior translation without limiting range of motion (ROM). Therefore, the objective of this study was to compare these parameters between an intact rotator cuff, MCT, and allograft FL SCR. METHODS: Eight fresh cadavers were studied using a custom shoulder testing system. ROM, superior translation, and subacromial contact pressure were measured in each of 3 states: (1) intact rotator cuff, (2) MCT, and (3) MCT with SCR. RESULTS: Total ROM was increased in the MCT state at 60° of abduction (P = .037). FL SCR did not restrict internal or external rotational ROM. Increased superior translation was observed in the MCT state at 0° and 30° of humeral abduction, with no significant difference between the intact cuff and FL SCR states. The MCT state significantly increased mean subacromial contact pressure at 0° of abduction with 30° and 60° of external rotation, and FL SCR restored this to intact levels. Peak subacromial contact pressure was increased for the MCT state at 0° of abduction with 30° and 60° of external rotation, as well as 30° of abduction with 30° of external rotation. CONCLUSION: This study demonstrates a tensor FL allograft preparation technique for use in SCR. After MCT, FL SCR restores ROM, superior translation, and subacromial contact pressure to the intact state.

Pulmonary hemorrhage in children with Alagille syndrome undergoing cardiac catheterization.

OBJECTIVES: To evaluate the incidence, severity, and outcomes of pulmonary hemorrhage in children with Alagille syndrome (AGS) undergoing cardiac catheterization, and to find variables associated with hemorrhage in this population. BACKGROUND: Children with AGS have a high incidence of bleeding complications during invasive procedures. It has been our impression that catheterization-associated pulmonary hemorrhage is more common in children with AGS, but there are no published data on this topic. METHODS: This was a retrospective single institution study of children with AGS undergoing catheterization from 2010 to 2018. Pulmonary hemorrhage was defined as angiographic or fluoroscopic evidence of extravasated blood in the lung parenchyma, or blood suctioned from the endotracheal tube with documentation of pulmonary hemorrhage by the anesthesiologist or intensivist. Univariate comparisons were made between catheterizations that did and did not have pulmonary hemorrhage. RESULTS: Thirty children with AGS underwent 87 catheterizations, 32 (37%) with interventions on the branch pulmonary arteries (PA). There were 26 (30%) procedures with hemorrhage, the majority (65%) of which were self-limited or required less than 24 hr of mechanical ventilation. Moderate and severe hemorrhage occurred only in children with tetralogy of Fallot (TOF; 5 of 14, 36%). A higher right ventricle to aorta systolic pressure ratio (1.0 [0.85-1.1] vs. 0.88 [0.59-1.0], p = .029) and interventions on the branch PAs (14 of 26, 54% vs. 18 of 61, 30%, p = .032) were associated with hemorrhage. CONCLUSIONS: Pulmonary hemorrhage was common in children with AGS undergoing both intervention and diagnostic cardiac catheterization, and was associated with TOF, higher RV to aorta pressure ratio, and interventions on the branch PAs.

Benzoyl-CoA conjugate accumulation as an initiating event for male reprotoxic effects in the rat? Structure-activity analysis, species specificity, and in vivo relevance.

A number of para-substituted benzoic acids (p-BA) and chemicals metabolized to p-BA have been found to confer adverse effects in male rats on sperm viability, motility, and morphology. These effects are putatively associated with the metabolism of p-BA to toxic intermediates. We had shown that p-BA lead to accumulation of high levels of p-alkyl-benzoyl-CoA conjugates in plated primary rat hepatocytes. Here we further investigated the relevance of this metabolic pathway for the reprotoxic effects in rats and rabbits. We extended the structure-activity relationship to a set of 19 chemicals (nine reprotoxic and ten non-reprotoxic) and confirmed a very strong correlation between p-alkyl-benzoyl-CoA accumulation in rat hepatocytes and the toxic outcome. Species specificity was probed by comparing rat, rabbit and human hepatocytes, and p-benzoyl-CoA accumulation was found to be specific to the rat hepatocytes, not occurring in human hepatocytes. There was also very limited accumulation in hepatocytes from rabbits that are a non-responder species in in vivo studies. Tissues of rats treated with 3-(4-isopropylphenyl)-2-methylpropanal were analysed and p-isopropyl-benzoyl-CoA conjugates were detected in the liver and in the testes in animals at toxic doses indicating that the metabolism observed in vitro is relevant to the in vivo situation and the critical metabolite does also occur in the reproductive tissue. These multiple lines of evidence further support benzoyl-CoA accumulation as a key initiating event for a specific group of male reproductive toxicants, and indicate a species-specific effect in the rat.

Transcatheter redirection of hepatic venous blood to treat unilateral pulmonary arteriovenous malformations in a Fontan circulation by short-term total exclusion of the unaffected lung.

Clinically significant unilateral pulmonary arteriovenous malformations (PAVM) can develop in patients with a Fontan circulation when there is unbalanced distribution of hepatic venous (HV) blood flow to the lungs. There are reported surgical and transcatheter techniques to treat PAVMs by rerouting HV return, with promising short-term results. We report a case of a novel, technically simple transcatheter approach to redirect HV blood flow in an adult Fontan patient with polysplenia syndrome and severe unilateral PAVMs. Our patient had a two-stage procedure, the first to redirect all HV blood flow to the affected lung with a single covered stent, and a second to confirm resolution of PAVMs and to reintroduce HV effluent to the unaffected lung. At 10-month follow-up, her oxygen saturations had increased from 75% to 93% with a marked improvement in her functional status.

Subcutaneous and Intravenous Treprostinil Pharmacokinetics in Children With Pulmonary Vascular Disease.

This study evaluated the pharmacokinetics of intravenous (IV) and subcutaneous (SC) treprostinil in pediatric patients with pulmonary vascular disease, and compared them with existing adult data from a similar cohort. Blood samples were collected from pediatric patients receiving steady-state IV or SC treprostinil and were assessed for plasma treprostinil concentration using liquid chromatography and tandem mass spectrometry. Forty participants, 15 receiving IV and 25 receiving SC treprostinil, were included in the analysis. Age ranged from 0.1 to 15.6 years. The median dose of treprostinil was 45.5 ng·kg·min with a range of 8-146 ng·kg·min. There was a linear relationship between treprostinil dose and plasma concentration with an R of 0.57. On average, there were higher blood concentrations per given dose of IV treprostinil compared with those per given dose of SC, but the difference was not significant. Compared with adult data, the slope of the pediatric data was similar, but the y-intercept was significantly lower. Additionally, the concentration per dose ratio was significantly higher in adults compared with children. Pediatric patients have significantly lower average blood concentrations of treprostinil per given dose compared with adults, and higher, but not significantly so, blood concentrations when treprostinil is administered IV as compared with SC administration.

Anterior Capsule Reconstruction Versus Pectoralis Major Transfer for Irreparable Subscapularis Tears Involving the Anterior Capsule: A Comparative Biomechanical Cadaveric Study.

PURPOSE: To compare the biomechanical effectiveness of human dermal allograft (HDA) anterior capsular reconstruction (ACR) and pectoralis major tendon transfer (PMTT) for treating irreparable subscapularis tears with capsular insufficiency in human cadaver shoulders. METHODS: Glenohumeral rotational range of motion and translation were measured in 6 cadaveric shoulders under the following 5 conditions: intact, deficient subscapularis/anterior capsule, ACR using HDA, HDA ACR with concomitant PMTT, and PMTT alone. RESULTS: The deficient subscapularis/anterior capsule condition significantly increased external and total rotational range of motion at 0° (P < .001, P < .001) and 30° (P = .005, P = .002) abduction as well as anterior-inferior translation (P ≤ .001 to .03). HDA ACR, both with and without PMTT, restored anterior-inferior stability to that of the intact condition; however, PMTT alone did not restore anterior-inferior translation or rotational range of motion. CONCLUSIONS: HDA ACR for treating irreparable subscapularis tears with capsular insufficiency restored anterior-inferior glenohumeral translation and rotational range of motion at time 0 in human cadaver shoulders. CLINICAL RELEVANCE: Anterior capsule reconstruction may be a viable option for treating massive irreparable subscapularis tears with capsular insufficiency.

A biomechanical cadaveric study of patellar tendon allograft as an alternative graft material for superior capsule reconstruction.

HYPOTHESIS: In a cadaveric irreparable rotator cuff tear model, patellar tendon allograft-superior capsule reconstruction (PT-SCR) will restore glenohumeral stability and reduce subacromial contact pressures without significant graft deformation during testing. METHODS: Eight cadaveric shoulders were tested in a custom shoulder testing system. Rotational range of motion (ROM), superior translation, and subacromial contact pressure were measured in the following experimental conditions: intact rotator cuff, irreparable supraspinatus tear (massive cuff tear [MCT]), and PT-SCR. RESULTS: MCT and PT-SCR resulted in significantly increased total ROM at all degrees of abduction compared with the intact state (P < .001). In both 0° and 30° of glenohumeral abduction, MCT showed a significant increase in superior translation compared with the intact state (P < .001). Application of the PT-SCR resulted in a decrease of superior translation compared with MCT (P < .001). At 0° abduction/60° external rotation and 0° abduction/90° external rotation, MCT showed significantly greater peak subacromial contact pressure compared with the intact state (P < .006). At both of these positions, PT-SCR was able to reduce peak pressure to lower than or no significant difference from the intact state. There was no statistically significant change in graft thickness, length, or width after testing. CONCLUSION: PT-SCR was able to reduce superior translation of the humeral head and peak subacromial contact pressure without restricting ROM. Furthermore, there was no significant graft deformation during testing. PT-SCR in this validated cadaveric model demonstrates favorable biomechanical properties and is a viable source of graft material for SCR.

Coarctation Index Predicts Recurrent Aortic Arch Obstruction Following Surgical Repair of Coarctation of the Aorta in Infants.

Recurrent aortic arch obstruction (RAAO) remains a major cause of morbidity following surgical neonatal repair of coarctation of the aorta (CoA). Elucidating predictors of RAAO can identify high-risk patients and guide postoperative management. The Coarctation index (CoA-I), defined as the ratio of the diameter of the narrowest aortic arch segment to the diameter of the descending aorta, has been used to help diagnose RAAO in neonates following the Norwood Procedure. We sought to assess the predictive value of the CoA-I on RAAO after CoA repair in infants with biventricular circulation. Clinical, surgical, and echocardiographic data of infants with biventricular circulation following neonatal CoA repair between 2010 and 2014 were evaluated. RAAO was defined using a composite quantitative outcome variable: a blood pressure gradient >20, a peak aortic arch velocity >3.5 m/s by echocardiogram, or a catheter-measured peak-to-peak gradient >20 within 2 years of surgery. Univariate and multivariate logistic regression analyses were used. Of the 68 subjects included in the analysis, 15 (22%) met criteria for RAAO. In the multivariate model, only CoA-I (OR 35.89, 95% CI 6.08-211.7, p < 0.0001) and use of patch material (OR 9.26, 95% CI 1.57-54.66, p = 0.014) were associated with increased risk of RAAO. The odds of developing RAAO was higher in patients with a CoA-I less than 0.7 (OR 33.8, 95% CI 5.7-199.5, p < 0.001). Postoperative CoA-I may be used to predict RAAO in patients with biventricular circulation after repair of CoA. Patients with a CoA-I less than 0.7 or patch aortoplasty warrant close follow-up.

Supine and Standing AP Pelvis Radiographs in the Evaluation of Pincer Femoroacetabular Impingement.

BACKGROUND: Pelvic tilt can affect the presence of the ischial spine sign and crossover sign. Numerous studies of pelvic tilt on radiographic measurements of pincer impingement have shown that increasing anterior tilt is associated with more radiographic signs of pincer impingement. However, to our knowledge, no study has directly compared supine and standing plain radiographs in patients with respect to lateral center-edge (LCE) angle, acetabular inclination, crossover sign, and ischial spine sign. QUESTIONS/PURPOSES: The purpose of this study was to evaluate the differences in supine and standing AP pelvis radiographs as they relate to the radiographic parameters of pincer impingement in an adult population evaluated for femoroacetabular impingement, specifically intrapelvic distances (sacrococcygeal to symphysis [SC-S] and coccyx tip to symphysis [T-S]), crossover sign (presence and percentage), LCE angle, inclination, and ischial spine sign. METHODS: Between August 2013 and June 2014, we obtained supine and standing radiographs for all new patients younger than 60 years who were evaluated for hip pain, when the diagnosis of fracture was not being considered; these formed the basis of this retrospective study. Patients were excluded if they had arthritis (Tönnis grade ≥ 2), lumbar fusion, previous hip surgery, or malrotated films. Forty-six hips, symptomatic side, met the inclusion criteria (age of patients, 33 ± 14 years; 13 males, 33 females). Radiographic data that were collected included SC-S distance, T-S distance, LCE angle, acetabular inclination, presence and percentage of crossover sign, and presence of ischial spine sign. A paired t-test was used to compare continuous variables and chi-square test was used for categorical variables. Two independent readers performed measurements. RESULTS: From supine to standing films, the T-S distance decreased from 19 ± 18 mm to 6 ± 19 mm (p < 0.001), and SC-S distance decreased from 47 ± 19 mm to 32 ± 20 mm (p < 0.001), indicating less pelvic tilt in the standing position. The number of hips that had crossover signs decreased from supine (n = 18, 39%) to standing (n = 9, 20%) (p = 0.039). The amount of crossover decreased from 23% ± 10% to 11% ±13% (p < 0.001). LCE angle did not change (27° ± 7° to 27° ± 8°) (p = 0.64) and inclination angle increased by a small amount (4.2° ± 5° to 5.3° ± 5°) (p = 0.002). The ischial spine sign decreased from supine (n = 20, 43%) to standing (n = 7, 15%) position (p = 0.003). CONCLUSIONS: There is a decrease in the amount of pelvic tilt on standing AP pelvis radiographs resulting in a decrease in the incidence and amount of crossover sign and ischial spine sign, and a small increase in inclination. Standing radiographs should be the standard in evaluation of nonarthritic hip pain, specifically pincer femoroacetabular impingement. Surgeons should use caution in interpreting supine AP radiographs in the evaluation of pincer impingement, specifically the crossover sign. LEVEL OF EVIDENCE: Level III, diagnostic study.