Thoracic aortic aneurysm in an adolescent with intraoperative discovery of contained rupture: a case report.

Background: As surgical recommendations in adults based on size criteria of ascending aortic aneurysms become more refined, criteria for childhood/adolescence remains less clear. Multiple pathologic factors may predispose younger patients to thoracic aortic aortopathy and increase the risk of rupture. An evolving field of research is how to identify thoracic aortic dilation earlier in patients, risk stratify, and to obtain objective measures beyond size for proceeding with surgical intervention in order to prevent catastrophic thoracic aortic dissection. Case Description: We report an adolescent case of dilated ascending aortic aneurysm with a functionally unicuspid/bicuspid aortic valve. This patient was taken to surgery electively, given the gradual increasing size of the ascending aorta. Intraoperatively, there was an unexpected intraoperative finding of a contained aortic rupture. The patient underwent an aortic root replacement with mechanical valve composite graft and coronary artery reimplantation (modified Bentall) with ascending hemiarch replacement. The patient did well with no post-operative complications. Aortic pathology and genetic analysis were performed. The patient was discovered to have a heterozygous variant in PTPN11 which is typically associated with Noonan syndrome; however, this is not known to be associated with aortopathy. Conclusions: As criteria for surgical intervention in adult thoracic ascending aortic aneurysms continues to evolve, this case illustrates challenges when determining the optimal criteria for surgical intervention in adolescent patients.

Critical Illness-Related Corticosteroid Insufficiency (CIRCI) After Pediatric Cardiac Surgery.

Although current studies do not support the routine use of corticosteroids after cardiopulmonary bypass in pediatric patients, there is incomplete understanding of the potential hemodynamic contribution of postoperative critical illness-related corticosteroid insufficiency in the intensive care unit. By reviewing the available studies and underlying pathophysiology of these phenomena in critically ill neonates, we can identify a subset of patients that may benefit from optimal diagnosis and treatment of receiving postoperative steroids. A suggested algorithm used at our institution is provided as a guideline for treatment of this high-risk population.

Extremely Long-Term Follow-Up of Dr William Glenn's Original Patient Cohort With Superior Cavopulmonary Anastomosis (1958-1990).

BACKGROUND: Historically, Dr William Glenn performed the first classic superior cavopulmonary anastomosis in a seven-year-old child at Yale in 1958. By 1990, this operation was performed consecutively in over 90 patients. With over 60 years of follow-up, this is the longest survival record of early Glenn patients from the first 30 years. METHODS: We performed a single center, retrospective evaluation of patients undergoing a Glenn operation. A collected list of surviving patients, previously updated in 1988, included demographics, age at procedure, and underlying diagnosis. Follow-up data were obtained in May 2022 using electronic medical records to determine survival, age of survivors, and age of deceased. RESULTS: Ninety-five patients underwent the Glenn operation from 1958 to 1990: 58.9% (n = 56) were male and 41.1% (n = 39) female. Fifteen patients were lost to follow-up, but 12 were alive in 1988. Sixty patients were deceased (68.1%), with an average age of 33.5 ± 18.3(range, 2-78, excluding seven early deaths) years. The oldest patient who passed away was a 78-year-old male with tetralogy of Fallot. Twenty patients remain alive, with an average age of 47.5 (range, 32-66) years. Four patients who are still alive today (20% survivors) are older than 60 years. CONCLUSIONS: Since Dr Glenn's original operation, the technique, timing, and indications have been modified (ie, bidirectional Glenn) to adapt to the current era. By following this initial group of patients, we can approach completion of the survival rates for adult congenital patients who were some of the first pediatric patients to receive this ground-breaking palliative procedure.

Enhanced congenital cardiac surgery knowledge with multidisciplinary collaborative education series for paediatric cardiology fellows and nurse practitioners.

INTRODUCTION: Paediatric cardiologists and nurse practitioners lack structured education tools focused on basic cardiac surgery principles. However, non-surgical specialties caring for surgical patients require this knowledge for comprehensive clinical care. We created a cardiac surgical educational curriculum focused on improving knowledge and attitudes towards communication for non-surgical trainees and advanced practice providers. METHODS: Over one academic year, six paediatric cardiology fellows and seven paediatric cardiac surgery nurse practitioners at Seattle Children's Hospital participated in this study. With surgical supervision, six lectures were prepared by each fellow and delivered monthly. Sessions were hybrid and recorded for later viewing. Pre- and post-intervention survey of attitudes regarding surgical topics and pre- and post- test-based knowledge assessments were administered. RESULTS: Participants positively rated the usefulness of the lecture series (4.2/5) and would recommend it to a colleague (4.5/5). Self-reported confidence discussing surgical concepts with patients increased from 2.3 to 3.4 among paediatric cardiology fellows (p < 0.001) and from 2.8 to 3.9 among nurse practitioners (p < 0.001), out of 5. In both groups, knowledge assessment scores improved from 54 to 79% post-intervention (p < 0.001). CONCLUSIONS: After a six-part educational series taught by paediatric cardiology fellows, both paediatric cardiology fellows and paediatric cardiac surgery nurse practitioners demonstrated improved knowledge and reported increased comfort counselling families on basic cardiac surgery topics. Structured, active-learning lessons taught by fellows for non-surgical audiences can improve attitudes and build clinically relevant knowledge. Creating an effective level-appropriate multidisciplinary curriculum accessible to various types of medical providers could enhance comprehensive care of complex congenital cardiac surgery patients.

Computed Tomographic 3-Dimensional Virtual Dissection Aiding in Diagnosis and Surgical Planning of a Rare Form of Obstructed Supracardiac Total Anomalous Pulmonary Venous Connection With an Unusual Scimitar-Like Arrangement.

We present a case of a newborn with a rare presentation of obstructed supracardiac total anomalous pulmonary venous connection who required emergent cannulation to extracorporeal membrane oxygenation (ECMO). Computed tomographic angiography of the heart was performed and using novel virtual dissection techniques aided in surgical planning and guidance. Computed tomographic angiography can be successfully performed in neonates with complex congenital heart disease on ECMO without adjustment of flows to aid in surgical management and novel virtual dissection techniques aid in complex anatomical delineation and spatial orientation with noncardiac structures. The preoperative imaging in this case allowed for appropriate and detailed presurgical planning and contributed to the excellent outcome of this patient.

Pioneers in congenital cardiac surgery: Dr. William Imon Norwood, Jr, MD, PhD.

"Innovation is not only the fountainhead but the life's blood of our specialty, of surgery, of medicine, of business, or of just about anything that is progressing, evolving, and improving. In the absence of innovation there is stagnation and ultimately there is decay. Cardiac surgery, particularly congenital cardiac surgery, must continue to evolve through innovation."

Complete atrioventricular septal defect with absent or diminutive primum component: Incidence, anatomic characteristics, and outcomes.

BACKGROUND: Repair of complete atrioventricular septal defect with absent or diminutive primum defect is challenging because of atrial septal malposition and abnormal anatomy of the left atrioventricular valve. We sought to define the incidence, anatomy, and surgical outcomes of this entity. METHODS: We identified all patients in our institutional database presenting for complete atrioventricular septal defect repair from 2006 to 2018. Operative reports and echocardiograms were reviewed to determine the presence and size of the primum defect, atrioventricular valve anatomy, degree of atrioventricular valve regurgitation, repair method, and complications, including reoperation for atrioventricular valve regurgitation. Functionally univentricular patients and those receiving repair at an outside institution were excluded. RESULTS: Of 183 patients with complete atrioventricular septal defect, absent/diminutive primum defect occurred in 16 patients (8.7%; 10 absent, 6 diminutive). Six patients (38%) had leftward malposition of the atrium septum on the common atrioventricular valve. The rate of reoperation for left atrioventricular valve regurgitation was 31% (3 early, 2 late), for which preoperative predictors included leftward malposition of the atrial septum onto the common atrioventricular valve (4/6 patients with malposition required reoperation, P = .036, Fisher exact test). One patient exhibiting this risk factor died. The overall rate of moderate or greater left atrioventricular valve regurgitation on the most recent postoperative echocardiogram was 13% (2/16 patients; median follow-up, 141 days; range, 3-2236 days). CONCLUSIONS: Complete atrioventricular septal defect with absent or diminutive primum defect is a unique variant of complete atrioventricular septal defect for which the risk of reoperation for left atrioventricular valve regurgitation after complete repair is high and risk factors include leftward malposition of the atrial septum on the common atrioventricular valve.

Diaphragmatic Hernia Perforation Leading to Fecopneumothorax.

Hiatal hernia is a common diagnosis. Unless symptomatic, most hiatal hernias are not repaired; in rare cases, however, severe complications can develop during conservative treatment. Although fecopneumothorax occurrence has been described in trauma and related to colonic pathology, it has not been described as occurring from spontaneous strangulation of a hiatal hernia. Regardless of the etiology, prompt recognition of the rare occurrence of fecopneumothorax is imperative. This report describes the presentation, diagnosis, and treatment of a patient presenting with a type IV hiatal hernia that resulted in colonic ischemia, perforation, and fecopneumothorax.

Injectable Shear-Thinning Hydrogels Prevent Ischemic Mitral Regurgitation and Normalize Ventricular Flow Dynamics.

Injectable hydrogels are known to attenuate left-ventricular (LV) remodeling following myocardial infarction (MI), dependent on material mechanical properties. The effect of hydrogel injection on ischemic mitral regurgitation (IMR) resultant from LV remodeling remains relatively unexplored. This study uses multiple imaging methods to evaluate the efficacy of injectable hydrogels with tunable modulus to prevent post-MI development of IMR. Posterolateral MI was induced in 20 sheep with subsequent epicardial injection of saline (control (MI); n = 7), soft hydrogel (guest-host crosslinking, modulus <1 kPa, n = 7), or stiff hydrogel (dual-crosslinking, modulus = 41.4 ± 4.3 kPa, n = 6) within the infarct region and 8-week follow-up. IMR and valve geometry were assessed by echocardiography. LV geometry (long-axis dimension, posterior chordae length) and ventricular flow dynamics were assessed by magnetic resonance imaging. IMR developed in MI controls at 8 weeks and was attenuated with hydrogel treatment (IMR grade for MI: 1.86 ± 0.69; guest-host crosslinking: 1.29 ± 1.11; dual-crosslinking: 0.50 ± 0.55, P = 0.02 vs MI). Tethering of the posterior leaflet increased in MI controls, but not with stiff hydrogel treatment. Across cohorts, IMR was correlated with changes in the long-axis dimension (Spearman R = 0.77) and posterior chordae length (Spearman R = 0.64). Intraventricular flow dynamics were highly disturbed in MI controls, but stiff hydrogel treatment normalized flow patterns and reduced the prevalence of large (≥2+ MR, >5 mL) regurgitant volumes. Injectable hydrogels attenuated subvalvular remodeling and leaflet tethering, preventing IMR development and normalizing LV flow dynamics. Hydrogels with a supraphysiological modulus yielded best outcomes.

Robotic Resection of Ectopic Parathyroid Glands in the Superior Posterior Mediastinum.

Background: Ectopic parathyroid glands can present in a challenging location in the superior posterior mediastinum. Methods: Two patients with primary hyperparathyroidism were operated on for ectopic paraesophageal parathyroid glands in the superior posterior mediastinum. Sestamibi scan, computed tomography (CT) scan, and photon emission CT were used to identify the exact location of these glands. We describe a minimally invasive resection using a three-arm robotic-assisted thoracoscopic technique. Results: Both lesions were completely resected with using the port-based robotic approach with expedited recovery. There was no perioperative morbidity. Patient had low postoperative pain scores and improved symptomatically. Conclusion: Robotic approach for resection of superior posterior mediastinal parathyroids is safe and effective in this challenging operative location.

Computational sensitivity investigation of hydrogel injection characteristics for myocardial support.

Biomaterial injection is a potential new therapy for augmenting ventricular mechanics after myocardial infarction (MI). Recent in vivo studies have demonstrated that hydrogel injections can mitigate the adverse remodeling due to MI. More importantly, the material properties of these injections influence the efficacy of the therapy. The goal of the current study is to explore the interrelated effects of injection stiffness and injection volume on diastolic ventricular wall stress and thickness. To achieve this, finite element models were constructed with different hydrogel injection volumes (150µL and 300 µL), where the modulus was assessed over a range of 0.1kPa to 100kPa (based on experimental measurements). The results indicate that a larger injection volume and higher stiffness reduce diastolic myofiber stress the most, by maintaining the wall thickness during loading. Interestingly, the efficacy begins to taper after the hydrogel injection stiffness reaches a value of 50kPa. This computational approach could be used in the future to evaluate the optimal properties of the hydrogel.

Injectable Shear-Thinning Hydrogels for Minimally Invasive Delivery to Infarcted Myocardium to Limit Left Ventricular Remodeling.

BACKGROUND: Injectable, acellular biomaterials hold promise to limit left ventricular remodeling and heart failure precipitated by infarction through bulking or stiffening the infarct region. A material with tunable properties (eg, mechanics, degradation) that can be delivered percutaneously has not yet been demonstrated. Catheter-deliverable soft hydrogels with in vivo stiffening to enhance therapeutic efficacy achieve these requirements. METHODS AND RESULTS: We developed a hyaluronic acid hydrogel that uses a tandem crosslinking approach, where the first crosslinking (guest-host) enabled injection and localized retention of a soft (<1 kPa) hydrogel. A second crosslinking reaction (dual-crosslinking) stiffened the hydrogel (41.4±4.3 kPa) after injection. Posterolateral infarcts were investigated in an ovine model (n≥6 per group), with injection of saline (myocardial infarction control), guest-host hydrogels, or dual-crosslinking hydrogels. Computational (day 1), histological (1 day, 8 weeks), morphological, and functional (0, 2, and 8 weeks) outcomes were evaluated. Finite-element modeling projected myofiber stress reduction (>50%; P<0.001) with dual-crosslinking but not guest-host injection. Remodeling, assessed by infarct thickness and left ventricular volume, was mitigated by hydrogel treatment. Ejection fraction was improved, relative to myocardial infarction at 8 weeks, with dual-crosslinking (37% improvement; P=0.014) and guest-host (15% improvement; P=0.058) treatments. Percutaneous delivery via endocardial injection was investigated with fluoroscopic and echocardiographic guidance, with delivery visualized by magnetic resonance imaging. CONCLUSIONS: A percutaneous delivered hydrogel system was developed, and hydrogels with increased stiffness were found to be most effective in ameliorating left ventricular remodeling and preserving function. Ultimately, engineered systems such as these have the potential to provide effective clinical options to limit remodeling in patients after infarction.

Slice-by-Slice Pressure-Volume Loop Analysis Demonstrates Native Differences in Regional Cardiac Contractility and Response to Inotropic Agents.

BACKGROUND: Regional changes in diastolic and systolic properties after myocardial infarction contribute to adverse left ventricular (LV) remodeling. Regional function is currently assessed using load-dependent measures such as slice ejection fraction (sEF), wall motion abnormalities, or strain imaging. However, load-independent measures of cardiac function may be useful in the study of the infarction-induced remodeling. METHODS: In this study, we used a recently validated 2-dimensional (2D) real-time magnetic resonance imaging (MRI) technique to evaluate regional variations in load-independent slice-by-slice measures of systolic and diastolic function and compared the values to a load-dependent measure in 11 sheep at rest and during inotropic agent infusion. RESULTS: Slice-derived ejection fraction (sEF) was greater in the apex relative to the midventricular and basal regions, and inotropic infusion increased sEF in the base more than in the apex and midventricle. Slice-derived ESPVR (sESPVR) in the apex was significantly lower than in the midventricle and the base, and inotropic infusion increased sESPVR in the apical slices more than in the midventricle. Similarly, slice-derived volume-axis intercept V0 (sV0) was higher in the base relative to the midventricle and apex. sEDPVR did not demonstrate significant regional variations, but inotropic infusion resulted in a small increase in the apex. CONCLUSIONS: In conclusion, acquisition of slice-derived load-independent measures demonstrated variations that contradict those observed with load-dependent sEF. The approach may provide advanced slice-based measures of function during the LV remodeling process and aid in the development of therapies.

The Influence of Mitral Annuloplasty on Left Ventricular Flow Dynamics.

BACKGROUND: Mitral valve (MV) repair using annuloplasty rings is the preferred method of treatment for MV regurgitation, but the impact of annuloplasty ring placement on left ventricular intraventricular flow has not been studied. METHODS: Annuloplasty rings of varying sizes were placed in 5 healthy sheep (intercommissural ring sizes were 24, 26, 28, 30, and 32 mm), and three-dimensional phase contrast magnetic resonance imaging (4D flow MRI) was performed before and 1 week after ring placement. RESULTS: Normal diastolic flow consisted of diastolic intraventricular vortices that naturally unwound during systole. Postsurgical intraventricular flow was highly disturbed in all sheep, and the disturbance was greatest for undersized rings. Ring size was highly correlated with the diastolic inflow angle (Pearson's r = -0.62, p < 0.1, 95% confidence interval: -0.92 to 0.14). There was a mean angle increase of mean diastolic inflow angle increase of 12.3 degrees (< 30 mm, p < 0.01, 95% confidence interval: 4.8 to 19.6) for rings less than 30 mm. There was an inverse relationship between peak velocity and annuloplasty ring area (Pearson's r = -0.80, p < 0.05, 95% confidence interval: -0.96 to -0.2). Transmitral pressure gradients increased significantly from baseline 0.73 ± 0.18 mm Hg to after annuloplasty 2.31 ± 1.04 mm Hg (p < 0.05). CONCLUSIONS: Mitral valve annuloplasty ring placement disturbs normal left ventricular intraventricular flow patterns, and the degree of disturbance is closely associated with annuloplasty ring size.

Suture forces in undersized mitral annuloplasty: novel device and measurements.

PURPOSE: To demonstrate the first use of a novel technology for quantifying suture forces on annuloplasty rings to better understand the mechanisms of ring dehiscence. DESCRIPTION: Force transducers were developed, attached to a size 24 Physio ring, and implanted in the mitral annulus of an ovine animal. Ring suture forces were measured after implantation and for cardiac cycles reaching peak left ventricular pressures (LVP) of 100, 125, and 150 mm Hg. EVALUATION: After implantation of the undersized ring to the flaccid annulus, the mean suture force was 2.0±0.6 N. During cyclic contraction, the anterior ring suture forces were greater than the posterior ring suture forces at peak LVPs of 100 mm Hg (4.9±2.0 N vs 2.1±1.1 N), 125 mm Hg (5.4±2.3 N vs 2.3±1.2 N), and 150 mm Hg (5.7±2.4 N vs 2.4±1.1 N). The largest force was 7.4 N at 150 mm Hg. CONCLUSIONS: The preliminary results demonstrate trends in annuloplasty suture forces and their variation with location and LVP. Future studies will significantly contribute to clinical knowledge by elucidating the mechanisms of ring dehiscence while improving annuloplasty ring design and surgical repair techniques.

Real-time magnetic resonance imaging technique for determining left ventricle pressure-volume loops.

BACKGROUND: Rapid determination of the left ventricular (LV) pressure-volume (PV) relationship as loading conditions are varied is the gold standard for assessment of LV function. Cine magnetic resonance imaging (MRI) does not have sufficient spatiotemporal resolution to assess beat-to-beat changes of the LV PV relationship required to measure the LV end-systolic elastance (EES) or preload-recruitable stroke work (PRSW). Our aim was to investigate real-time MRI and semiautomated LV measurement of LV volume to measure PV relations in large animals under normal and inotropically stressed physiologic conditions. METHODS: We determined that PV relationships could be accurately measured using an image exposure time Tex less than 100 ms and frame rate Tfr less than 50 ms at elevated heart rates (∼140 beats per minute) using a golden angle radial MRI k-space trajectory and active contour segmentation. RESULTS: With an optimized exposure time (Tex=95 ms and frame rate Tfr=2.8 ms), we found that there was no significant difference between cine and real-time MRI at rest in end-diastolic volume, end-systolic volume, ejection fraction, stroke volume, or cardiac output (n=5, p<0.05) at either normal or elevated heart rates. We found EES increased from 1.9±0.7 to 3.1±0.3 mm Hg/mL and PRSW increased from 6.2±1.2 to 9.1±0.9 mm Hg during continuous intravenous dobutamine infusion (n=5, p<0.05). CONCLUSIONS: Real-time MRI can assess LV volumes, EES, and PRSW at baseline and elevated inotropic states.