Comparison of Perioperative and Postoperative Outcomes Among 3 Left Atrial Incisions: Conventional Direct, Transseptal, and Superior Septal Left Atriotomy.

BACKGROUND: Achieving optimal exposure of the mitral valve during surgical intervention poses a significant challenge. This study aimed to compare perioperative and postoperative outcomes associated with 3 left atriotomy techniques in mitral valve surgery-the conventional direct, transseptal, and superior septal approaches-and assess differences during the surgical procedure and the postoperative period. METHODS: Inclusion criteria were patients undergoing mitral valve surgery from January 2010 to December 2020, categorized into 3 cohorts: group 1 (conventional direct; n = 115), group 2 (transseptal; n = 33), and group 3 (superior septal; n = 59). To bolster sample size, the study included patients undergoing mitral valve surgery independently or in conjunction with other procedures (eg, coronary artery bypass grafting, aortictricuspid surgery, or maze procedure). RESULTS: No substantial variance was observed in the etiology of mitral valve disease across groups, except for a higher incidence of endocarditis in group 3 (P = .01). Group 1 exhibited a higher frequency of elective surgeries and isolated mitral valve procedures (P = .008), along with reduced aortic clamping and cardiopulmonary bypass durations (P = .002). Conversely, group 3 patients represented a greater proportion of emergency procedures (P = .01) and prolonged intensive care unit and hospital stays (P = .001). No significant disparities were detected in terms of permanent pacemaker implantation, postoperative complications, or mortality among the groups. CONCLUSION: Mitral valve operations that employed these 3 atriotomy techniques demonstrated a safe profile. The conventional direct approach notably reduced aortic clamping and cardiopulmonary bypass durations. The superior septal method was primarily employed for acute pathologies, with no significant escalation in postoperative arrhythmias or permanent pacemaker implantation, although these patients had prolonged intensive care unit and hospital stays. These outcomes may be linked to the underlying pathology and nature of the surgical intervention rather than the incision method itself.

Aortic Dilatation on the Edge of Dissection-Do We Operate Too Late? The Ratio between Ascending and Descending Aorta DiameteR (RADAR).

(1) Background: There is a need for a novel surrogate marker to ease decision making when facing ascending aortic dilatation. In this article, we study the ratio between ascending and descending aorta diameters as a potential one. (2) Methods: Retrospective observational cohort study, including all the patients who underwent surgery for acute type A aorta dissection (aTAAD) between January 2014 and September 2020 at our center. A total of 50 patients were included. Clinical and demographic data were collected. The anatomical measurements were made including orthogonal maximal diameters of the ascending and descending aorta, post-dissection whole circumference length (post-wCL), post-dissection true lumen circumference length (post-tCL), and surface and sphericity indices of the ascending and descending aorta. Pre-dissection ascending aorta diameter (pre-AAD) and pre-dissection descending aorta diameter (pre-DAD) were calculated as well as the ratio between them and compared with reference values. (3) Results: Of the pre-AAD patients, 96% had smaller than the recommended 55 mm. The ratio between the descending and ascending aorta pre-dissection diameters was significantly smaller compared to the reference value (0.657 ± 0.125 versus 0.745 ± 0.016 with a mean difference of -0.088 and a p < 0.001). (4) Conclusions: The 55 mm threshold for aorta maximal diameter is an insufficient criterion when assessing the risk of dissection. The ratio between DAD and AAD is a parameter worthy of analysis as a tool to stratify the risk of dissection.

Three-dimensional printed moulds to obtain silicone hearts with congenital defects for paediatric heart-surgeon training.

OBJECTIVES: Many types of congenital heart disease are amenable to surgical repair or palliation. The procedures are often challenging and require specific surgical training, with limited real-life exposure and often costly simulation options. Our objective was to create realistic and affordable 3D simulation models of the heart and vessels to improve training. METHODS: We created moulded vessel models using several materials, to identify the material that best replicated human vascular tissue. This material was then used to make more vessels to train residents in cannulation procedures. Magnetic resonance imaging views of a 23-month-old patient with double-outlet right ventricle were segmented using free open-source software. Re-usable moulds produced by 3D printing served to create a silicone model of the heart, with the same material as the vessels, which was used by a heart surgeon to simulate a Rastelli procedure. RESULTS: The best material was a soft elastic silicone (Shore A hardness 8). Training on the vessel models decreased the residents' procedural time and improved their grades on a performance rating scale. The surgeon evaluated the moulded heart model as realistic and was able to perform the Rastelli procedure on it. Even if the valves were poorly represented, it was found to be useful for preintervention training. CONCLUSIONS: By using free segmentation software, a relatively low-cost silicone and a technique based on re-usable moulds, the cost of obtaining heart models suitable for training in congenital heart defect surgery can be substantially decreased.

Short-term outcomes of aortic valve neocuspidization for various aortic valve diseases.

Objectives: Bioprosthetic valve deterioration remains a major limitation following aortic valve replacement. Favorable results have been reported with an autologous pericardium aortic valve neocuspidization. Methods: Seventy patients (31 women and 39 men) (mean age, 62 ± 12 years) with aortic stenosis (n = 52 [74%]) or aortic regurgitation (n = 18 [26%]) underwent the aortic valve neocuspidization procedure. Thirty-four patients (49%) had a tricuspid valve, 35 (50%) had a bicuspid valve, and 1 (1%) had a monocuspid valve. European System for Cardiac Operative Risk Evaluation and Society of Thoracic Surgeons scores were, respectively, 2.2% ± 2% and 2.0% ± 1.8%. Four patients (6%) had active endocarditis and 2 (3%) had endocarditis sequelae. One patient (1%) had fibroelastoma. A combined procedure was performed in 33 patients (46%). Results: The follow-up period was 24 ± 12 months. One patient (1%) died in hospital and 1 patient (1%) underwent conventional valve replacement for significant aortic regurgitation. Postoperative peak and mean pressure gradients were respectively 14 ± 5 and 8 ± 3 mm Hg. Aortic valve area was 2.5 ± 0.6 cm2. During follow-up, no patients died. Reintervention occurred in 2 patients (3%). At last follow-up, peak pressure gradient was 13 ± 7 mm Hg, mean pressure gradient was 7 ± 4 mm Hg, and aortic valve area was 2.3 ± 0.7 cm2. There was 1 recurrence of moderate aortic stenosis (1%). All patients were in New York Heart Association functional class I (90%) or II (10%). Freedom from major valve-related events was 92.1%, (98.5% for death, 95.2% for reintervention, and 95.2% for endocarditis). Conclusions: In our experience, the midterm outcomes of the aortic valve neocuspidization procedure with autologous glutaraldehyde fixed pericardium were acceptable for survival, operative risk and valve-related complications, for our all-comer patient population with various aortic valve diseases.

Enhanced Vascular Biocompatibility and Remodeling of Decellularized and Secured Xenogeneic/Allogeneic Matrices in a Porcine Model.

BACKGROUND/PURPOSE: Calcifications and absence of growth potential are the major drawbacks of glutaraldehyde-treated prosthesis. Decellularized and secured xeno-/allogeneic matrices were assessed in a preclinical porcine model for biocompatibility and vascular remodeling in comparison to glutaraldehyde-fixed bovine pericardium (GBP; control). METHODS: Native human (fascia lata, pericardium) and porcine tissues (peritoneum) were used and treated. In vitro, biopsies were performed before and after treatment to assess decellularization (hematoxylin and eosin/DAPI). In vivo, each decellularized and control tissue sample was implanted subcutaneously in 4 mini-pigs. In addition, 9 mini-pigs received a patch or a tubularized prosthesis interposition on the carotid artery or abdominal aorta of decellularized (D) human fascia lata (DHFL; n = 4), human pericardium (DHP; n = 9), porcine peritoneum (DPPt; n = 7), and control tissue (GBP: n = 3). Arteries were harvested after 1 month and subcutaneous samples after 15-30 days. Tissues were processed for hematoxylin and eosin/von Kossa staining and immunohistochemistry for CD31, alpha-smooth muscle actin, CD3, and CD68. Histomorphometry was achieved by point counting. RESULTS: A 95% decellularization was confirmed for DHP and DPPt, and to a lower degree for DHFL. In the subcutaneous protocol, CD3 infiltration was significantly higher at day 30 in GBP and DHFL, and CD68 infiltration was significantly higher for GBP (p < 0.05). In intravascular study, no deaths, aneurysms, or pseudoaneurysms were observed. Inflammatory reaction was significantly higher for DHFL and GBP (p < 0.05), while it was lower and comparable for DHP/DPPt. DHP and DPPt showed deeper recellularization, and a new arterial wall was characterized. CONCLUSIONS: In a preclinical model, DPPt and DHP offered better results than conventional commercialized GBP for biocompatibility and vascular remodeling.

Porcine pulmonary valve decellularization with NaOH-based vs detergent process: preliminary in vitro and in vivo assessments.

BACKGROUND: Glutaraldehyde fixed xenogeneic heart valve prosthesis are hindered by calcification and lack of growth potential. The aim of tissue decellularization is to remove tissue antigenicity, avoiding the use of glutaraldehyde and improve valve integration with low inflammation and host cell recolonization. In this preliminary study, we investigated the efficacy of a NaOH-based process for decellularization and biocompatibility improvement of porcine pulmonary heart valves in comparison to a detergent-based process (SDS-SDC0, 5%). METHODS: Native cryopreserved porcine pulmonary heart valves were treated with detergent and NaOH-based processes. Decellularization was assessed by Hematoxylin and eosin/DAPI/alpha-gal/SLA-I staining and DNA quantification of native and processed leaflets, walls and muscles. Elongation stress test investigated mechanical integrity of leaflets and walls (n = 3 tests/valve component) of valves in the native and treated groups (n = 4/group). Biochemical integrity (collagen/elastin/glycosaminoglycans content) of leaflet-wall and muscle of the valves (n = 4/group) was assessed and compared between groups with trichrome staining (Sirius Red/Miller/Alcian blue). Secondly, a preliminary in vivo study assessed biocompatibility (CD3 and CD68 immunostaining) and remodeling (Hematoxylin and eosin/CD31 and ASMA immunofluorescent staining) of NaOH processed valves implanted in orthotopic position in young Landrace pigs, at 1 (n = 1) and 3 months (n = 2). RESULTS: Decellularization was better achieved with the NaOH-based process (92% vs 69% DNA reduction in the wall). Both treatments did not significantly alter mechanical properties. The detergent-based process induced a significant loss of glycosaminoglycans (p < 0,05). In vivo, explanted valves exhibited normal morphology without any sign of graft dilatation, degeneration or rejection. Low inflammation was noticed at one and three months follow-up (1,8 +/- 3,03 and 0,9836 +/- 1,3605 CD3 cells/0,12 mm2 in the leaflets). In one animal, at three months we documented minimal calcification in the area of sinus leaflet and in one, microthrombi formation on the leaflet surface at 1 month. The endoluminal side of the valves showed partial reendothelialization. CONCLUSIONS: NaOH-based process offers better porcine pulmonary valve decellularization than the detergent process. In vivo, the NaOH processed valves showed low inflammatory response at 3 months and partial recellularization. Regarding additional property of securing, this treatment should be considered for the new generation of heart valves prosthesis. Graphical abstract of the study.

Decellularized and Secured Porcine Arteries with NaOH-based Process: Proof of Concept.

BACKGROUND: There is a need for small caliber vascular prosthesis. Synthetic grafts are hindered by thrombogenicity and rapid occlusion. Decellularized matrices could be an alternative. We assessed in vitro and in vivo the biocompatibility of porcine artery treated with a chemical/physical process for decellularization and graft securitization with non/conventional pathogens inactivation. METHODS: Porcine carotid arteries (PCA) were treated. First, biopsies (n = 4/tissue) were performed before/after treatment to assess decellularization (hematoxylin and eosin/-4',6-diamidino-2-phenylindole/DNA/Miller). Second, 5 rats received an abdominal aortic patch of decellularized PCA (DPCA). Four pigs received subcutaneous DPCA implants (n = 2/pig). Half were explanted at day 15 and half at day 30. Finally, 2 pigs received DPCA (n = 2) and polytetrafluoroethylene prosthesis (n = 1), respectively, as carotid interposition. Implants were removed at day 30. Inflammation (CD3 and CD68 immunostaining) calcifications (von Kossa staining), remodeling (hematoxylin and eosin), and vascular characterization (CD31 and alpha-smooth muscle actin immunofluorescent staining) were investigated. RESULTS: Ninety-five percentage of decellularization was obtained without structural deterioration. No death occurred. Low inflammatory reaction was found in the 2 models for DPCA. Acquisition of vascular identity was confirmed in the rodent and porcine models. Similarity between native PCA and DPCA was observed after 30 days. In contrast, polytetrafluoroethylene graft showed severe calcifications, higher CD3 reaction, and higher intimal hyperplasia (P < 0.05). CONCLUSIONS: The physical and chemical process ensures decellularization of carotid porcine arteries and their in vivo remodeling with the presence of an endothelium and smooth-muscle-like cells as well as a low level of inflammatory cells.

Enhanced vascular regeneration with chemically/physically treated bovine/human pericardium in rodents.

BACKGROUND: Glutaraldehyde-treated pericardia for cardiovascular applications have poor long-term clinical results. The efficacy of a combined physical/chemical treatment to improve pericardium biocompatibility and vascular regeneration was assessed and compared with detergent treatment and two commercial bovine pericardia: PeriGuard (DGBP) and Edwards pericardium (nDGBP). The physical and chemical process was applied to bovine and human pericardia (DBP-DHP), and the detergent process was applied to bovine (DDBP). MATERIAL AND METHODS: Native (NBP) and treated bovine tissues were assessed for decellularization (HE/DAPI/DNA/α-Gal and MHC-1 staining) and mechanical integrity ex vivo. Twenty Wistar rats received subcutaneous patches of each bovine tissue to assess immunogenic response up to 4 months (flow cytometry). Ten additional rats received four subcutaneous bovine-treated patches (one/condition) to evaluate the inflammatory reaction (CD3/CD68 immunostaining), calcification (von Kossa staining/calcium quantification), and integration assessment (Hematoxylin and eosin staining). Finally, 15 rodents received a patch on the aorta (DBP n = 5, DHP n = 5, and DGBP n = 5), and vascular biocompatibility and arterial wall regeneration were assessed after 4 months (CD3/CD68/CD31/ASMA and Miller staining). RESULTS: DBP reached the higher level of decellularization, no immunogenic response whereas maintaining mechanical properties. DBP induced the lowest level grade of inflammation after 2 months (P < 0.05) concomitantly for better remodeling. No complications occurred with DBP and DHP where vascular regeneration was confirmed. Moreover, they induced a low level of CD3/CD68 infiltrations. CONCLUSIONS: This process significantly reduces immunogenicity and improves biocompatibility of bovine and human pericardia for better vascular regeneration.

Improvement in perioperative care in pediatric cardiac surgery by shifting the primary focus of treatment from cardiac output to perfusion pressure: Are beta stimulants still needed?

OBJECTIVE: An important aspect of perioperative care in pediatric cardiac surgery is maintenance of optimal hemodynamic status using vasoactive/inotropic agents. Conventionally, this has focused on maintenance of cardiac output rather than perfusion pressure. However, this approach has been abandoned in our center in favor of one focusing primarily on perfusion pressure, which is presented here and compared to the conventional approach. DESIGN: A retrospective study. SETTING: Regional center for congenital heart disease. University Hospital of Lausanne, Switzerland. PATIENTS: All patients with Aristotle risk score ≥8 that underwent surgery from 1996 to 2012 were included. Patients operated between 1996 and 2005 (Group 1: 206 patients) were treated according to the conventional approach. Patients operated between 2006 and 2012 (Group 2: 217 patients) were treated according to our new approach. INTERVENTIONS: All patients had undergone surgery for correction or palliation of congenital cardiac defects. OUTCOME MEASUREMENTS: Mortality, duration of ventilation and inotropic treatment, use of ECMO, and complications of poor peripheral perfusion (need for hemofiltration, laparotomy for enterocolitis, amputation). RESULTS: The two groups were similar in age and complexity. Mortality was lower in group 2 (7.3% in group 1 vs 1.4% in group 2, P < .005). Ventilation times (hours) and number of days on inotropic/vasoactive treatment (all agents), expressed as median and interquartile range [Q1-Q3] were shorter in group 2: 69 [24-163] hours in group 1 vs 35 [22-120] hours in group 2 (P < .01) for ventilation, and 9 [3-5] days in group 1 vs 7 [2-5] days in group 2 (P < .05) for inotropic/vasoactive agents. There were no differences in ECMO usage or complications of peripheral perfusion. CONCLUSIONS: Results in pediatric cardiac surgery may be improved by shifting the primary focus of perioperative care from cardiac output to perfusion pressure.

Single coronary artery and neonatal arterial switch operation: early and long-term outcomes.

OBJECTIVES: The presence of single coronary artery (CA) in the arterial switch operation (ASO) for neonatal treatment with transposition of the great arteries (TGA) has been reported to be an independent risk factor for early death after surgical repair and late reintervention. The study objective was to evaluate the mortality and the CA stenosis risk at early and long term in neonatal ASO for TGA and single CA. METHODS: Between January 1987 and January 2010, 979 neonates underwent an ASO, of which 73 had a single CA (7.5% of all cohort): right ostium with posterior left CA loop was the most frequent pattern (63%), followed by left ostium with an anterior right CA loop (26%). Mean age at operation was 9.3 ± 5.7 days. Mean follow-up was 9.8 years (range: 1-20 years). RESULTS: Eight patients (11%) died, 6 of coronary-related death. Overall, survival was 90.1 ± 1.9% at 1 year and 88.6% ± 3.8% at 2, 5, 10 and 15 years, respectively. Independent risk factor for mortality was associated surgery before 2001. Freedom from coronary events was 91.6 ± 3.3% at 1 year and 88.7 ± 3.8% at 5, 10 and 15 years respectively. No patients required late reintervention for CA surgery or angioplasty. CONCLUSIONS: All coronary-related death occurred within the first 6 months after ASO, and all patients but 1 were operated before 2001. In our experience, it appears that a single CA is not any more a risk factor for early and late mortality after ASO for TGA. Mortality has drastically reduced since 2001 and is now close to that found in TGA with standard coronary patterns. The acquired experience shared between the surgeons and the institution offsets the undeniable surgical difficulty.

Novel method of surgical preparation for transcatheter completion of Fontan circulation: creation of an extracardiac pathway.

BACKGROUND: The alliance between surgeons and interventionists has inspired creative techniques to surgically precondition the heart for subsequent transcatheter repair. The interest stems from the need to avoid repeated surgeries. Transcatheter Fontan completion of intracardiac pathway has been reported. AIM: To report a new surgical preparation for transcatheter completion of extracardiac Fontan circulation. METHODS: The inferior vena cava (IVC) was cut and anastomosed end-to-end with the inferior end of a Gore-Tex conduit in 20 lambs. A ring was placed around the IVC near the anastomosis. The superior vena cava was cut and connected with the right atrium (RA) auricle. In group 1 (n=9), the Gore-Tex conduit was occluded at both ends by a polytetrafluoroethylene membrane. In group 2 (n=11), the upper segment of the Gore-Tex tube was opened and connected to the RA to allow free flow of IVC blood. Fontan completion was attempted 1-3 months following surgery. Animals were sacrificed just after or 3 months after completion. RESULTS: All lambs were successfully preconditioned. We failed to complete the pathway in all animals from group 1 - autopsy showed occlusion of the pathway. In group 2, there was one postoperative death, one elective sacrifice after 2 months to assess pathway integrity, and nine successful completions. Autopsies showed widely patent pathway and well-deployed covered stents completely occluding the fenestrations. CONCLUSIONS: Circulating extracardiac conduit offers the best option to prepare for extracardiac Fontan completion. This surgical preparation opens new frontiers for transcatheter and hybrid techniques for extracardiac Fontan completion.

Neonatal right ventricle to pulmonary connection as a palliative procedure for pulmonary atresia with ventricular septal defect or severe tetralogy of Fallot.

OBJECTIVES: Right ventricle to pulmonary artery connection (RVPA connection) without prosthetic material has been our ideal strategy to palliate pulmonary atresia with ventricular septal defect (VSD) or severe tetralogy of Fallot for the last decade. We speculate that RVPA connection ensures adequate postoperative haemodynamics for symptomatic neonates and promotes pulmonary artery rehabilitation. The present study was undertaken to assess the outcome of this strategy. METHODS: Between 2000 and 2010, among 107 patients who benefited from an RVPA connection, 57 were neonates. Forty-eight of these underwent autologous tissue reconstruction, 5 using left atrial appendage. Median weight was 2.9 kg (range 1.8-4.4). Median Nakata index was 100 mm2/m2 (range 17-185 mm2/m2); 12% had major aortopulmonary collaterals. All patients were reviewed retrospectively. End-points were death or complete repair; reintervention for restrictive pulmonary blood flow was considered as failure. At follow-up, we evaluated reintervention after complete repair, and quality of life. RESULTS: There were 2 early deaths (RV hypoplasia and RV failure) and 3 late sudden deaths (range 3-6 months). Pulmonary blood flow required to be increased in 8 patients: 4 underwent shunt after a median delay of 1 month; RVPA connection enlargement was needed in 3; 1 patient had percutaneous angioplasty. Finally, 47 patients (81%) had a complete repair, of which 70% were performed without prosthetic material at a median age of 7 months (range 2-53), with a median Nakata index of 221 mm2/m2 (range 102-891). One patient died early and 1 was a failure with opening of the VSD after intracardiac repair. At last follow-up, 4 patients were still awaiting repair, with 1 late death and 5 who had required reintervention after intracardiac repair; there were 3 conduit replacements and 2 balloon dilatation patch enlargements. CONCLUSIONS: The neonatal RVPA connection approach (i) provides an acceptable survival rate with a satisfactory haemodynamic adaptation, (ii) facilitates rehabilitation of PAs and (iii) avoids the use of prosthetic graft at correction.

Levosimendan in a neonate with severe coarctation of aorta and low cardiac output syndrome.

We report successful use of levosimendan after failed balloon angioplasty in a critically ill neonate with coarctation of aorta (CoA) and severe low cardiac output syndrome (LCOS). Treatment with levosimendan improved left heart function, and decreased lactate and brain natriuretic peptide levels. To our knowledge, this is the first report on the safe and successful use of levosimendan in the management of LCOS due to severe CoA in a neonate awaiting surgical repair.

Feasibility of transapical aortic valve replacement through a left ventricular apical diverticulum.

Transapical aortic valve replacement is an established technique performed in high-risk patients with symptomatic aortic valve stenosis and vascular disease contraindicating trans-vascular and trans-aortic procedures. The presence of a left ventricular apical diverticulum is a rare event and the treatment depends on dimensions and estimated risk of embolisation, rupture, or onset of ventricular arrhythmias. The diagnosis is based on standard cardiac imaging and symptoms are very rare. In this case report we illustrate our experience with a 81 years old female patient suffering from symptomatic aortic valve stenosis, respiratory disease, chronic renal failure and severe peripheral vascular disease (logistic euroscore: 42%), who successfully underwent a transapical 23 mm balloon-expandable stent-valve implantation through an apical diverticulum of the left ventricle. Intra-luminal thrombi were absent and during the same procedure were able to treat the valve disease and to successfully exclude the apical diverticulum without complications and through a mini thoracotomy. To the best of our knowledge, this is the first time that a transapical procedure is successfully performed through an apical diverticulum.

Feasibility of creating a novel animal heart model to test transcatheter techniques for a cavocaval connection that mimics a Fontan completion.

OBJECTIVE: The objective of this study was to create a novel animal model to foster the future development of interventional techniques for a cavocaval connection that mimics a Fontan completion. METHODS: Ten sheep were studied. All had the superior vena cava-right atrium junction closed using a polytetrafluoroethylene membrane. A valveless Gore-Tex conduit connecting the terminal portion of the superior vena cava to the right atrium was used to bypass the polytetrafluoroethylene occlusion and to allow normal venous drainage through the right atrium. Radio-opaque nitinol rings were placed around the inferior vena cava near its entry in the right atrium to allow better fluoroscopic visualization and to enhance stent stability during transcatheter cavocaval connection. RESULTS: The first 3 animals died during the learning curve as a result of technical issues. The subsequent 7 surviving sheep showed good flow dynamics on cardiac catheterization. Transcatheter cavocaval connection was performed successfully performed in 6 sheep at 0 to 9 months after the initial surgery. Sacrifice was done electively in all animals at 1 to 9 months per protocol. One animal was euthanized early because of an untreatable infection. One sheep was observed as a control without a transcatheter cavocaval connection and was sacrificed at 12 months. CONCLUSIONS: A novel, chronic ovine model to foster development of transcatheter techniques for cavocaval connection to mimic a Fontan completion was created. The successful model is easily reproducible after a short learning curve and shows good survival.

Feasibility of transcatheter techniques for intracardiac and extracardiac cavocaval connection in principle for Fontan completion in chronic animal models.

OBJECTIVES: We report the safety and feasibility of various transcatheter techniques of cavocaval connection in principle for the completion of Fontan circulation in viable, chronic and ovine heart models. Surgically simulated preparations of both intracardiac and extracardiac cavocaval connections were studied. METHODS: Sixteen sheep were divided into two groups per the type of surgical preparation. All animals underwent standard right thoracotomy with interposition of a 20-mm Gore-tex(®) conduit between the superior vena cava (SVC) and the right atrium (RA). Nitinol rings were placed around the SVC and the inferior vena cava (IVC). In Group I (intracardiac, n = 10), the SVC-RA junction was closed using a polytetrafluoroethylene (PTFE) membrane 1 cm below the SVC-Gore-tex(®) anastomosis. In Group II (extracardiac, n = 6), a 20-mm Gore-tex conduit de-aired and filled with heparinized saline was anastomosed to connect the SVC and the IVC. The IVC end was anastomosed in a termino-lateral fashion and the SVC end in a termino-terminal fashion; both the ends were occluded with a PTFE membrane. Animals were scheduled for transcatheter cavocaval connection after a variable healing period. RESULTS: Four animals in Group I died; three early and one late after surgical preparation. After a median interim period of 1 month (0-9 months), five sheep from Group I and six from Group II underwent successful transcatheter cavocaval connection. Perforation of the PTFE membrane was successful in all animals. Covered stents were deployed precisely and with good stability ensured by the nitinol rings. All animals survived transcatheter completion and were sacrificed after a median follow-up of 4 months (0-8 months) per protocol. No stent migration, thromboembolic events, residual shunts or paraprosthetic leak was noticed on angiographic evaluation or at autopsy in any animal. CONCLUSIONS: Transcatheter techniques for completion of cavocaval connection in surgically simulated, chronic animal models is safe and feasible. Both techniques were equally successful with no failures or short-term complications. Such techniques should work in principle for completion of intracardiac and extracardiac Fontan circulation.

Bidirectional cavopulmonary shunt with additional pulmonary blood flow: a failed or successful strategy?

OBJECTIVES: In patients with single ventricle physiology, Fontan circulation is considered as the optimal surgical approach, although it entails a growing incidence of late complications. It has been speculated that the association of bidirectional cavopulmonary shunt (BCPS) and additional pulmonary blood flow (APBF) might provide long-lasting palliation. The present study was undertaken to assess the long-term outcome of this strategy. METHODS: A group of 70 patients with single ventricle physiology, who underwent BCPS with APBF between 1990 and 2000, were reviewed retrospectively. Median age at operation was 2 years (range: 0.1-27 years). Unilateral BCPS was performed in 60 patients (86%), bilateral BCPS in 9 and the Kawashima procedure in 1. APBF was provided through antegrade pulmonary outflow tract in 43 patients (61%) and by aortopulmonary shunt in 27 (39%). Two patients died early and three were lost to follow-up. Mean follow-up of the 65 remaining patients was 13.5 ± 4 years. End-points were death, need for heart transplantation (HTx) or Fontan completion and functional outcome. RESULTS: Five patients died (two after HTx, three from ventricular failure); overall actuarial survival was 89 ± 4% at 15 years. Six patients underwent HTx (one after Fontan completion) with two early deaths and no late mortality. Fifty-one patients underwent Fontan completion (11 with additional palliative procedures before completion); there was no early or late mortality following Fontan completion; one patient underwent HTx. Among the remaining six patients with BCPS and APBF, two were not suitable for Fontan completion and four remained suitable. Overall, clinical failure (mortality, HTx, unsuitability for Fontan completion) occurred in 13 patients (19%). Risk factors for clinical failure were older age at BCPS (P = 0.01) and postoperative complications after BCPS (P = 0.001). Considering late mortality, HTx and Fontan completion as strategic failures, the actuarial freedom from these events was 20 ± 5% at 10 years. CONCLUSIONS: BCPS with APBF approach: (i) fails as a strategy for definitive palliation, (ii) provides a high survival rate, (iii) does not preclude a successful Fontan completion and (iv) may delay the long-term deleterious consequences of Fontan circulation. Palliation by BCPS with APBF should be achieved early in life.

Cardiac and neurological assessment of normothermia/warm blood cardioplegia vs hypothermia/cold crystalloid cardioplegia in pediatric cardiac surgery: insight from a prospective randomized trial.

OBJECTIVE: Although normothermia and warm blood cardioplegia are widely used in adults, cold crystalloids and hypothermia remain routinely used in pediatric cardiac surgery. The superiority of either technique in both brain and myocardial protection remains controversial. We designed a prospective randomized study to compare both approaches in terms of early myocardial protection and late neurodevelopmental status. METHODS: From 2004 to 2005, 47 patients were randomly assigned to either mild hypothermia associated to cold crystalloid cardioplegia (CCC, 22 patients) or normothermia with intermittent warm blood cardioplegia (IWBC, 25 patients). Intramyocyte adenosine triphosphate (ATP) was measured before, during and after cardioplegic arrest and results between groups were compared. In addition to their cardiac status, early and late neurologic assessment was performed by psychometric evaluation tests. RESULTS: Intracellular ATP levels were not significantly different between the two groups. However, intragroup comparison revealed different profiles according to myocardial protection: in the normothermia/warm blood cardioplegia group, ATP concentration increased during cardioplegic arrest and returned to initial values afterward (11 nmol mg(-1) vs 21 nmol mg(-1) vs 10 nmol mg(-1), p < 0.001), such changes did not occur in the cold protocol (17 nmol mg(-1) vs 19 nmol mg(-1) vs 14 nmol mg(-1), p = NS). Early neurological outcome was similar in both groups. At late follow-up (mean = 4 years), no significant difference was observed between the two groups. CONCLUSIONS: This study demonstrates that normothermia/IWBC protocols are not deleterious when compared with more conventional approaches. A more physiologic ATP steady state, reflecting the absence of cellular ischemic insult was observed in the IWBC group. Importantly, no significant difference was found between IWBC and CCC groups in terms of early and late neurodevelopmental status.