Physiology of deep closed circuit rebreather mixed gas diving: vascular gas emboli and biological changes during a week-long liveaboard safari.

Introduction: Diving decompression theory hypothesizes inflammatory processes as a source of micronuclei which could increase related risks. Therefore, we tested 10 healthy, male divers. They performed 6-8 dives with a maximum of two dives per day at depths ranging from 21 to 122 msw with CCR mixed gas diving. Methods: Post-dive VGE were counted by echocardiography. Saliva and urine samples were taken before and after each dive to evaluate inflammation: ROS production, lipid peroxidation (8-iso-PGF2), DNA damage (8-OH-dG), cytokines (TNF-α, IL-6, and neopterin). Results: VGE exhibits a progressive reduction followed by an increase (p < 0.0001) which parallels inflammation responses. Indeed, ROS, 8-iso-PGF2, IL-6 and neopterin increases from 0.19 ± 0.02 to 1.13 ± 0.09 µmol.min-1 (p < 0.001); 199.8 ± 55.9 to 632.7 ± 73.3 ng.mg-1 creatinine (p < 0.0001); 2.35 ± 0.54 to 19.5 ± 2.96 pg.mL-1 (p < 0.001); and 93.7 ± 11.2 to 299 ± 25.9 µmol·mol-1 creatinine (p = 0.005), respectively. The variation after each dive was held constant around 158.3% ± 6.9% (p = 0.021); 151.4% ± 5.7% (p < 0.0001); 176.3% ± 11.9% (p < 0.0001); and 160.1% ± 5.6% (p < 0.001), respectively. Discussion: When oxy-inflammation reaches a certain level, it exceeds hormetic coping mechanisms allowing second-generation micronuclei substantiated by an increase of VGE after an initial continuous decrease consistent with a depletion of "first generation" pre-existing micronuclei.

Are surgeons ready to get the COVID-19 vaccine?

BACKGROUND: Vaccination against COVID-19 has started in several countries already and is on its way in others. However, there is an important hesitance towards the vaccine. The aim of this study is to evaluate the vaccination hesitance and main concerns towards the vaccine among surgeons. METHODS: An anonymous survey of 16 questions was sent to 138 Belgian surgeons before the start of vaccination in Belgium. The questions were divided into sections, evaluating demographics, COVID-19 test status and symptoms, the surgeon's opinion on the COVID-19 vaccination and their main concerns. RESULTS: Ninety-three out of 138 surgeons (67.4%) completed the survey: two-third of them were residents. Sixty-nine surgeons (74.2%) do want to get vaccinated. Forty-two surgeons (45.2%) feel like they do not have enough information about the vaccine. Residents feel significantly more underinformed than consultants (52.3% and 29.0%, respectively). Surgeons who feel to be well-informed are more willing to get vaccinated (92.2%) compared to those who feel to have a lack of information (52.4%). The main concerns among surgeons include effectiveness (26.9%), safety and side effects (19.4%) and organisation and vaccination strategy (12.9%). Twenty-five surgeons (26.9%) have no concerns at all. CONCLUSION: Most surgeons (74.2%) are ready for their COVID-19 vaccine. However, some of the surgeons are still doubtful about the vaccine. A lack of information plays a major role in their scepticism. A strong communication strategy is necessary to educate, reassure and motivate surgeons to get vaccinated.

Contegra versus pulmonary homograft for right ventricular outflow tract reconstruction in newborns.

OBJECTIVES: Pulmonary homografts are standard alternatives to right ventricular outflow tract reconstruction in congenital heart surgery. Unfortunately, shortage and conduit failure by early calcifications and shrinking are observed for small-sized homografts in younger patients. In neonates, Contegra® 12 mm (Medtronic Inc., Minneapolis, Minnesota, United States of America) could be a valuable alternative, but conflicting evidence exists. There is no published study considering only newborns with heterogeneous pathologies. We retrospectively compared the outcomes of these two conduits in this challenging population. METHODS: Patients who underwent a right ventricular outflow tract reconstruction between January 1992 and December 2014 at the Hôpital Universitaire des Enfants Reine Fabiola were included. We retrospectively collected and analysed demographic, echocardiographic, surgical, and follow-up data. RESULTS: Of the 53 newborns who benefited from a right ventricular outflow tract reconstruction during the considered period, 30 received a Contegra 12 mm (mean age 15 ± 8 days), and 23 a small (9-14 mm) pulmonary homograft (mean age 10 ± 7 days). Overall mortality was 16.6% with Contegra versus 17.4% in the pulmonary homograft group (p = 0.98 log-rank). Operative morbidity and early re-operation for conduit failure were not significantly different between the two groups. Mean follow-up in this study is 121 ± 74 months. Survival free from re-operation was not different between the two groups (p = 0.15). Multivariable analysis showed that weight and significant early gradient were factors associated with anticipated conduit failure. CONCLUSIONS: Contegra 12 mm is a valid alternative to small pulmonary homografts in a newborn patient population. TRIAL REGISTRATION: NCT03348397.

Obstructive teratoma in the right ventricle of a newborn: a case report.

BACKGROUND: A newborn was diagnosed by echocardiogram with an asymptomatic cardiac mass in the right ventricle after a systolic cardiac murmur was detected at birth. CASE PRESENTATION: Nine days after birth, the newborn presented with three syncopal episodes and oxygen desaturation which required resuscitation. The mass induced a complete right ventricular outflow tract obstruction. The presence of a patent foramen oval and a patent ductus arteriosus explained the absence of symptoms at birth. Surgery was rapidly considered since the situation was life threatening. The tumor was successfully resected. The mass was a mature teratoma confirmed by microscopic examination, illustrated by pictures and video. CONCLUSIONS: This case was unique because of the absence of symptoms in the first 9 days of the newborn's life even though symptoms should have mounted due to the obstruction postpartum. The delay was correlated to the closure of the patent ductus arteriosus. It is recommended that newborns with any cardiac mass be followed up regularly due to hemodynamic changes at birth.

Long-term survival and quality of life in Jehovah's witnesses after cardiac surgery: a case control study.

BACKGROUND: We previously analyzed morbidity and mortality in Jehovah's Witnesses patients after cardiac surgery compared to control population patients. Patients who were Jehovah's Witnesses were operated in accordance with their philosophical convictions and in respect of their refusal of transfusions. We propose to assess long-term survival and quality of life in the patients of this preliminary study. METHODS: We contacted 31 adult Jehovah's Witnesses patients who underwent heart surgery at the Brugmann hospital between 1991 and 2012 and compared them to a control population of 62 patients that had no transfusion restriction, and matched them for sex, age at the time of intervention and the type of surgery performed. We compared long-term quality of life in both populations through the MacNew software, a validated instrument to assess quality of life of patients with cardiovascular disease. The long-term survival of patients was analyzed by Kaplan Meier curves. RESULTS: Long-term quality of life and survival do not appear different between the two groups. Patient evaluation by MacNew software shows comparable physical (p = 0.54), emotional (p = 0.12), social (p = 0.21) and global (p = 0.25) scores between the two populations. The analysis of the actuarial survival curves shows no differences in terms of long-term survival of these patients (p = 0.37). CONCLUSIONS: Cardiac surgery in Jehovah's Witnesses can be performed with identical long-term quality of life and survival compared to surgery without blood transfusion restriction, if one follows rigorous blood conserving strategies. TRIAL REGISTRATION: NCT03348072 . Retrospectively registered 16 November 2017.

Pulmonary valve replacement after right ventricular outflow tract reconstruction with homograft vs Contegra®: a case control comparison of mortality and morbidity.

BACKGROUND: Repair of congenital heart defects involving the right ventricular outflow tract may require the implantation of a right ventricle to pulmonary artery conduit. This conduit is likely to be replaced during childhood. This study compares the operative outcomes of the replacement procedure of Contegra® and homografts in pulmonary position. METHODS: From 1999 to 2016, 82 children underwent 87 right ventricle to pulmonary artery conduit replacements (60 Contegra® and 27 homografts). Demographics, operative and clinical data were obtained through a retrospective review of the medical records. The two groups were matched for comparison using propensity score matching. All the procedures were performed by the same team of surgeons. RESULTS: No statistically significant difference was observed between the two groups when considering the operative data for anesthesia, surgery, cardiopulmonary bypass and aortic clamping durations. A peroperative complication rate of 13.47% and 15.36% in Contegra® and homograft replacement groups respectively (p value = 0.758) was observed. There was no difference regarding the blood loss and fluid input. No statistically significant difference was observed between the two groups for the post-operative morbidity. We considered the Pediatric Risk of Mortality (PRISM) score, the day of extubation, the day of withdrawal of inotropic drugs, the length of the intensive care unit stay and the length of hospital stay. The overall mortality is 2.3% but there is no statistically significant difference between the two groups. CONCLUSION: Right ventricle to pulmonary artery conduit replacement procedure can be achieved with a low surgical morbidity or mortality, not influenced by the type of conduit that is replaced. Therefore, the choice between homograft or Contegra® for right ventricle to pulmonary artery reconstruction should not be influenced by the future surgical risk during the replacement procedure. TRIAL REGISTRATION: NCT03048071 . Registered 9 February 2017 (retrospectively registered).

Contegra 12 mm: How Long Can It Last?

Since the year 2000, we have used Contegra conduits for right ventricular outflow tract reconstruction in infants and newborns. Published reports of early and late results from multiple centers have included variable and inconsistent findings. Concerns about the durability of small conduits placed in younger infants have been expressed. We report an interesting experience with a 12-mm Contegra conduit that we explanted 16 years after implantation in the course of repair of truncus arteriosus (common arterial trunk) in an infant.

Outcomes from cardiac surgery in Jehovah's witness patients: experience over twenty-one years.

BACKGROUND: Cardiac surgery in Jehovah's Witnesses may be challenging during the operation and postoperative period given their refusal of blood products. The aim of this study was to document our center's experience with Jehovah's Witnesses undergoing major cardiac surgery and to compare surgical outcomes with a matched control group. METHODS: We retrospectively reviewed the demographic, perioperative, and in-hospital postoperative data for 31 Jehovah's Witness patients undergoing surgery from 1991 to 2012 and compared findings with a control group of 62 patients of the same sex and age, who underwent the same type of operations in the same period. Early mortality, major in-hospital morbidity, laboratory findings, and hospital stays were compared between groups. RESULTS: Demographic data were similar between groups, except that more patients in the Jehovah's Witness group had extracardiac arteriopathy compared with controls (p = 0.04). There was no difference in predicted mortality, calculated by the Euroscore II, between groups (2.8 ± 3.3 in study group versus 2.4 ± 2.2 in control group, p = 0.469). For postoperative outcomes, there were no differences between Jehovah's Witnesses versus controls in hospital mortality (3 % versus 2 %, p = 0.548), total drain loss (847 ± 583 mL versus 812 ± 365 mL, p = 0.721), mechanical ventilation time (1.26 ± 2.24 versus 0.89 ± 0.55 days, p = 0.218), intensive care unit stay (4.3 ± 3.9 versus 3 ± 1.4 days, p = 0.080), and hospital stay (12.9 ± 7.6 versus 10.9 ± 6.6 days, p = 0.223). CONCLUSIONS: Outcomes after cardiac surgery are similar between Jehovah's Witnesses and general population, in centers applying rigorous blood patient management protocols.

Managing Ventricular Septal Defect with Associated Aortic Regurgitation: Two Decades of Experience.

BACKGROUND AND AIM OF THE STUDY: Ventricular septal defect (VSD) with aortic regurgitation (AR) is a well-known association. However, there is still no agreement about its management, particularly regarding the technical details of its operative treatment. The study aim was to describe all components of the syndrome and to evaluate the various techniques used with regards to its anatomical and functional features. METHODS: A total of 31 patients (mean age 7.4 years; range: 1.0-14.3 years) who underwent repair of VSD and AR between 1990 and 2013 was reviewed. The VSD was perimembranous in 22 patients, and subarterial in nine. Trusler's valvuloplasty technique was used in 15 patients, Yacoub's technique in seven, and Carpentier's technique (triangular resection) in four. Two patients underwent aortic valve replacement (AVR), and three patients with no significant aortic valve lesions underwent a simple patch repair of the VSD. RESULTS: The aortic valvuloplasty results were generally good, with an initial aortic valvuloplasty avoiding AVR. During the immediate postoperative period, valvuloplasty failure occurred in three patients, regardless of the technique used, and all three patients were reoperated on. The mean duration of follow up was 8.5 years (range: 3.2-20.6 years). The initial result was maintained in all patients, except for four who underwent late AVR. CONCLUSION: The study findings contributed to an analysis of VSD and AR, and helped to clarify the best surgical strategy. The results obtained suggest that adequacy of the initial repair is the most important determinant of subsequent evolution.

Cryoablation for a right atrial myxoma arising from the Koch's triangle: a case report.

A 78-year-old caucasian patient with compromised cardiac function presenting recurrent episodes of pulmonary embolism was referred to our center for resection of a voluminous right atrial myxoma arising from the Koch's triangle. To preserve the conduction system, we performed an excision of the myxoma associated with cryoablation of its stalk. This case is of special interest for discussing possibilities of preservation of the atrioventricular conduction system in such situations, provided that the contemporary literature does not propose concrete guidelines.

Endocarditis of bovine jugular vein conduit due to Q fever.

Contegra (Medtronic, Minneapolis, MN) conduits are routinely used in cases of right ventricular outflow tract reconstruction during congenital heart surgery. We report two cases of Q fever endocarditis involving Contegra conduits. Surgical treatment and distinct aspects of both unusual cases are described.

Ten-year experience with surgical treatment of adults with congenital cardiac disease.

The number of adults with congenital cardiac disease continues to increase, and adult patients are now more numerous than paediatric patients. We sought to identify risk factors for perioperative death and report our results with surgical management of adult patients with congenital cardiac disease. We retrospectively analysed in-hospital data for 244 consecutive adult patients who underwent surgical treatment of congenital cardiac disease in our centre between January, 1998 and December, 2007. The mean patient age was 27.2 plus or minus 11.9 years, 29% were in functional class III or IV, and 25% were cyanosed. Of the patients, half were operated on for the first time. A total of 61% of patients underwent curative operations, 36% a reoperation after curative treatment, and 3% a palliative operation. Overall mortality was 4.9%. Predictive factors for hospital death were functional class, cyanosis, non-sinus rhythm, a history of only palliative previous operation(s), and an indication for palliative treatment. Functional class, cyanosis, type of initial congenital cardiac disease (single ventricle and double-outlet right ventricle), and only palliative previous operation were risk factors for prolonged intensive care stay (more than 48 hours). The surgical management of adult patients with congenital cardiac disease has improved during recent decades. These generally young patients, with a complex pathology, today present a low post-operative morbidity and mortality. Patients having undergone palliative surgery and reaching adulthood without curative treatment present with an increased risk of morbidity and mortality. Univentricular hearts and double-outlet right ventricles were associated with the highest morbidity.

Ventricular septal defect closure in Taussig-Bing heart: the "pulmonic rule".

Accurate ventricular septal defect patch sizing and tailoring remain challenging in many surgical procedures. Surgical exposure frequently limits complete visualization of the ventricular septal defect. Moreover, examination of the heart cavity under cardioplegic arrest may lead to skewed appreciation of the ventricular septal defect caliber and shape. Here we describe a simple and safe surgical tip to predict the size and shape of the ventricular septal defect patch in Taussig-Bing malformation before starting extracorporeal circulation. The patch should be circular with a diameter equal to the under pressure, proximal, pulmonary artery diameter.

Cardiac ochronosis: not so benign.

A 78-year-old patient with ochronosis has developed symptomatic aortic stenosis. He has undergone an aortic valve replacement that was highly complicated by a severe aortic calcification. The right coronary artery was sacrificed and bypassed in order to control a massive aortic root haemorrhage. The patient has presented a sternal dehiscence that required surgical revision. The sternal frailty was related to chronic corticotherapy in a patient with chronic spondylarthrosis. Cardiac ochronosis in the elderly may be associated to surgical complications related to severe aortic root calcifications and chronic corticotherapy for arthropathies.

Ventricular septal defect closure in tetralogy of Fallot: the aortic rule.

Ventricular septal defect (VSD) closure is an important part of the surgical repair of tetralogy of Fallot and related anomalies. Visual appreciation of the VSD size (either transinfundibular or transatrial) can be misleading. My colleagues and I describe a simple and precise way to predict the size and shape of the VSD patch before extracorporeal circulation: the patch should be circular with a diameter identical to that of the mid ascending aorta.

Inhaled nitric oxide versus prostacyclin in chronic shunt-induced pulmonary hypertension.

OBJECTIVE: Cardiac surgery for congenital heart defects is commonly complicated by shunt-induced chronic pulmonary hypertension and associated acute hypertensive crises. To investigate the effects of vasodilators in chronic and acute pulmonary hypertension, we used the innominate artery to create a growing aortopulmonary shunt in young piglets. METHODS: Pulmonary hemodynamics and right ventricular function and their responses to hypoxia, intravenous prostacyclin, and inhaled nitric oxide were investigated after closure of the shunt by using pulmonary flow-pressure relationships, pulmonary vascular resistance partitioning, pulmonary vascular impedance, and ventriculoarterial coupling expressed as the ratio of right ventricular end-systolic elastance to effective pulmonary arterial elastance. RESULTS: Shunt-induced pulmonary hypertension was associated with medial hypertrophy of pulmonary arteries, increased resistance, increased elastance, increased wave reflection, and preserved ventriculoarterial coupling. Hypoxic pulmonary vasoconstriction was blunted in the shunt group. Compared with prostacyclin, inhaled nitric oxide was a more effective vasodilator in the shunt group and in hypoxia. Effective pulmonary arterial elastance and right ventricular end-systolic elastance increased in chronic (shunt) and acute (hypoxic) hypertension and decreased with vasodilators, preserving a normal coupling. CONCLUSIONS: A growing aortopulmonary shunt in the young pig is a reliable model of chronic pulmonary hypertension, with medial hypertrophy, increased resistance, and increased elastance. In this model inhaled nitric oxide is a better pulmonary vasodilator than intravenous prostacyclin, with neither drug having a specific inotropic effect, and normal coupling is preserved in chronic and acute pulmonary hypertension.

Bosentan for the prevention of overcirculation-induced experimental pulmonary arterial hypertension.

BACKGROUND: The dual endothelin-receptor antagonist bosentan has been reported to improve pulmonary arterial hypertension, but the role of endothelins in the pathogenesis of the condition remains uncertain. We investigated the roles of endothelin-1 (ET-1), nitric oxide (NO), vascular endothelial growth factor (VEGF), and tenascin in overcirculation-induced pulmonary hypertension in piglets, as a model of early pulmonary arterial hypertension, with or without bosentan therapy. METHODS AND RESULTS: Thirty 3-week-old piglets were randomized to placebo or to bosentan 15 mg/kg BID after the anastomosis of the left subclavian artery to the pulmonary arterial trunk or after a sham operation. Three months later, the animals underwent a hemodynamic evaluation followed by cardiac and pulmonary tissue sampling for morphometry, immunohistochemistry, and real-time quantitative PCR. Chronic systemic-to-pulmonary shunting increased circulating plasma ET-1, pulmonary mRNA for ET-1, ET(B) receptor, inducible NO synthase, VEGF, and pulmonary ET-1 and VEGF proteins. There were increases in myocardial mRNA for ET(A) receptor and VEGF and in myocardial VEGF protein. Pulmonary and myocardial tissue mRNA for tenascin did not change. Normalized-flow pulmonary artery pressure increased from 20 (2) to 33 (1) mm Hg [mean (SEM)], arteriolar medial thickness increased on average by 83%, and these changes were completely prevented by bosentan therapy. Right ventricular end-systolic elastance increased in proportion to pulmonary arterial elastance with or without bosentan. CONCLUSIONS: Experimental overcirculation-induced pulmonary arterial hypertension appears to be causally related to an activation of the pulmonary ET-1 system and as such is completely prevented by the dual endothelin receptor antagonist bosentan.

Early results of valved bovine jugular vein conduit versus bicuspid homograft for right ventricular outflow tract reconstruction.

BACKGROUND: Homograft conduits are preferable for right ventricular outflow tract reconstruction in children, but their limited availability remains a major concern. Recently, a valve-containing segment of bovine jugular vein (Contegra, Medtronic Inc, Minneapolis, MN) has been introduced as a potential alternative conduit. METHODS: Early clinical and echocardiographic results of right ventricular outflow tract reconstruction were retrospectively compared between 41 children (mean age, 1.9 years), receiving a Contegra conduit and 36 patients (mean age, 2.7 years) with a size-reduced pulmonary homograft. RESULTS: Clinical outcome was comparable with two early deaths in the homograft group and one in the Contegra group. There were no conduit-related complications in either population. Early echocardiographic assessment showed only trivial to mild regurgitation in 9 homografts versus 17 Contegra conduits. The peak gradient across the right ventricular outflow tract conduit was comparable for both groups, although a larger number of patients, treated with a downsized homograft, had a small gradient at the distal junction with the pulmonary arteries (12 versus 6 patients). None of the patients had a gradient at the valvar level. CONCLUSIONS: The valved bovine jugular vein conduit offers a promising substitute for right ventricular outflow tract reconstruction in infants and children, with an early hemodynamic performance that compares favorably with downsized, bicuspid homografts. Clinical advantages are greater shelf availability and the natural continuity between valve and conduit, which allows proximal infundibular shaping without additional material. However, durability must be determined, even though most of these children will require right ventricular outflow tract reoperation after outgrowing the conduit.