Modification of bicaval anastomosis technique for orthotopic heart transplantation

Optimizing Anastomoses Technique in Orthotopic Heart Transplantation: Comparison of Biatrial, Bicaval and Modified Bicaval Technique

Implantation techniques for orthotopic heart transplantation (HTx) have evolved over the centuries. Recently new approaches of modified bicaval techniques to minimize warm ischemia are gaining popularity in the literature. Between 2010 and 2022 n = 238 patients underwent HTx in our department. The recipients were retrospectively reviewed and divided regarding their anastomoses’ technique. Anastomoses were sutured either in biatrial (n = 37), bicaval (n = 191) or in a modified bicaval (n = 10) manner with suturing of the superior cava vein and A. pulmonalis anastomosis after removing the aortic cross-clamp during the reperfusion. Warm ischemia was 62 ± 11 min for biatrial, 66 ± 15 min for bicaval, but only 48 ± 10 min for modified bicaval technique (p < 0.001). The incidence of severe primary graft dysfunction (PGD) was comparable between biatrial (27.0%) and bicaval (28.8%) anastomoses. In contrast, in patients with modified bicaval technique PGD occurred only in a single patient (10.0%). The incidence of postoperative pacemaker implantation was 18.2% for biatrial compared to 3.0% for bicaval and 0.0% for modified bicaval technique (p = 0.01). The modified bicaval technique enables to decrease the crucial warm ischemia during HTx compared to both biatrial and regular bicaval techniques. Therefore, we strongly recommend bicaval anastomoses, ideally in a modified manner.

Sarcopenia and risk of infection in adult heart transplant recipients in Japan

AIMS

Heart transplantation (HT) is an effective therapeutic option for end-stage heart failure. Infection is a major cause of morbidity and mortality after HT. Sarcopenia, defined as the loss of muscle mass and strength, is a common comorbidity in HT candidates with end-stage heart failure. However, the effects of sarcopenia on the occurrence of post-HT infections are not well understood. Therefore, we explored the association between the skeletal muscle mass and post-transplant infections in adult HT recipients.

METHODS AND RESULTS

We retrospectively examined the records of 135 patients who underwent HT between August 2007 and November 2019 at our institution. Pre-transplant computed tomography was used to calculate the skeletal muscle index (SMI) at the level of the third lumbar vertebra. Muscle wasting was defined as the SMI of the lowest sex-based tertiles. The primary endpoint was infections within 6 months of HT. The study included 109 patients (80 men, mean age: 41.6 ± 12.0 years): 37 patients in the muscle wasting group and 72 patients in the non-muscle wasting group. The mean SMI values in the muscle wasting and non-muscle wasting groups were 29.9 ± 4.8 cm² /m² and 40.7 ± 6.7 cm² /m² , respectively. Prior to HT, 108 (99.1%) patients were on left ventricular assist device support, and during that support, the rate of late right heart failure was significantly higher in the muscle wasting group than non-muscle wasting group (P = 0.012). Sixteen infections occurred within 6 months of HT. The most common infection sites included the respiratory tract (n = 5) and the upper gastrointestinal tract (n = 5), followed by the urinary tract (n = 4). Overall, 10 patients experienced infections in the muscle wasting group (27.0%) and 6 in the non-muscle wasting group (8.3%) (P = 0.009). Two patients in the muscle wasting group required intensive care unit admission, compared to none in the non-muscle wasting group. Low skeletal muscle mass was associated with infections in the univariate and multivariate logistic regression models (hazard ratio: 3.68, 95% confidence interval: 1.19-11.3; P = 0.023). However, the duration of all-cause mortality within 3 years did not differ between the groups (P = 0.56).

CONCLUSIONS

Low skeletal muscle mass is a predictor of post-HT infections within 6 months of HT.

Effect of Therapeutic Modification on Outcomes in Heart Transplantation Over the Past Two Decades - A Single-Center Experience in Japan

BACKGROUND

During these 2 decades (1999-2019), many therapeutic strategies have been developed in the field of heart transplant (HTx) to improve post-HTx outcomes. In the present study, 116 consecutive HTx adults between 1999 and 2019 were retrospectively reviewed to evaluate the influences of a therapeutic modification on post HTx outcomes.Methods and Results:Patient survival, functional status and hemodynamics after HTx and modification of therapeutic strategies were reviewed. The overall cumulative survival rate at 10 and 20 years post-HTx was 96.4 and 76.7%, respectively. There were no significant differences in survival rate or exercise tolerance after HTx between extracorporeal and implantable continuous flow-LVAD. Post-HTx patient survival in patients, irrespective of the donor risk factors such as donor age, low LVEF, history of cardiac arrest, was equivalent across cohorts, while longer TIT and higher inotrope dosage prior to procurement surgery were significant risk factors for survival. In 21 patients given everolimus (EVL) due to renal dysfunction, serum creatinine significantly decreased 1 year after initiation. In 22 patients given EVL due to transplant coronary vasculopathy (TCAV), maximum intimal thickness significantly decreased 3 years after initiation.

CONCLUSIONS

The analysis of a 20-year single-center experience with HTx in Japan shows encouraging improved results when several therapeutic modifications were made; for example, proactive use of donor hearts declined by other centers and the use of EVL in patients with renal dysfunction and TCAV.

Benefits of the Modified Bicaval Anastomosis Technique for Orthotopic Heart Transplantation From a Size-Mismatched Marginal Donor

BACKGROUND

Size-mismatched heart transplantation (HTx) is associated with a risk of stenosis of the caval anastomosis site or low cardiac output syndrome. We developed a modified bicaval anastomosis technique (mBCAT) that achieved an adjustable caval anastomosis to compensate for size mismatch. This study was performed to validate the rationale of the mBCAT for size-mismatched HTx.Methods and Results:This institutional consecutive series involved 106 patients who underwent HTx with the mBCAT during an 18-year period. The cohort was divided into 3 groups according to the donor-to-recipient body weight ratio: <0.8, undersized group (n=17); 0.8-1.3, size-matched group (n=68); and >1.3, oversized group (n=21); outcomes were compared. The undersized, size-matched, and oversized groups showed no significant differences in the rate of mild or worse echocardiographic tricuspid regurgitation at 1 month [1 (5.8%), 7 (10.2%), and 1 (4.8%), respectively; P=0.87] or the survival rate at 10 years [100%, 93.9%, and 100%, respectively; P=0.25]. The right heart catheter study revealed no pressure gradient across the orifices of both cavae in any patient. Additionally, the cardiac index immediately post-HTx was significantly low in the undersized group (P=0.008), but was similar to the other groups at 6 months post-HTx (P=0.16).

CONCLUSIONS

The mBCAT prevented caval anastomosis-related complications in size-mismatched HTx and achieved excellent hemodynamics regardless of donor size.

Application of modified bicaval technique for pediatric heart transplant with oversized donor heart

Whereas bicaval technique is an effective surgical method, standard bicaval technique for younger age and donor/recipient caval mismatch was reported to have a risk of superior vena caval obstruction. Between 2016 and 2019, three patients with dilated cardiomyopathy aged 10 years or younger underwent orthotropic heart transplantation with modified bicaval technique at our institute. Donor/recipient body weight and height ratios were 2.36, 0.77, and 2.61 and 1.37, 0.94, and 1.51, respectively. All patients were preoperatively supported by a left ventricular assist device: Excor Pediatric in two patients and Jarvik 2000 in one. Duration of LVAD support was 180, 238, and 220 days. One patient required revision of pulmonary anastomosis during the operation; accordingly, the chest was closed 3 days later. There was no mortality. Caval obstructions were not observed. Three months after the operation, tricuspid regurgitation was mild in two patients and trivial in one.

Perioperative ischaemic reperfusion injury and allograft function in the early post-transplantation period

OBJECTIVES

Ischaemic reperfusion injury (IRI) is an inevitable complication of heart transplantation (HTX) and is observed as a pathological finding in biopsies from transplanted allografts. The aim of this study was to evaluate the severity of IRI and determine the clinical outcomes of HTX in patients with severe IRI.

METHODS

We enrolled 74 consecutive patients who had undergone HTX since 2007. Endomyocardial biopsy samples were obtained from the right ventricle of the transplanted heart. IRI was graded as 'trivial', 'mild', 'moderate' or 'severe' according to the extent of IRI-specific findings in the samples. The cohort was divided into a moderate-to-severe IRI group with 21 patients [IRI(+)] and a low-grade group with 53 patients [IRI(-)].

RESULTS

The frequency of mechanical circulatory support and duration of catecholamine dependence in the early postoperative period were significantly higher in the IRI(+) group compared to the IRI(-) group. However, overall survival after HTX and mid-term cardiac allograft function were not significantly different between the groups. Among perioperative factors, cardiac ischaemic time was significantly different between the groups [IRI(-) vs IRI(+), 199 ± 38 min vs 239 ± 39 min; P < 0.001]. Incremental increases in cardiac ischaemic time were correlated with increases in IRI severity. Serum troponin T levels 3 h after donor heart reperfusion was significantly correlated with cardiac ischaemic time (r = 0.418, P = 0.0007).

CONCLUSIONS

IRI is associated with a complicated clinical course in the early post-HTX period due to temporary deterioration of allograft function. This may be attributable to myocardial stunning caused by long donor heart ischaemic time during HTX.

Modified Bicaval Technique in Orthotopic Heart Transplantation - Comparison With Conventional Bicaval Technique

BACKGROUND

Orthotopic heart transplantation (HT) is the treatment of choice for patients with end-stage heart failure (HF). The bicaval technique was introduced as a safe alternative minimizing modification of atrial geometry. The modification of bicaval anastomosis is suggested to compensate for caliber mismatch and small donor. The present study was performed to compare these 2 techniques in terms of postoperative CT scan and clinical outcomes. Methods and Results: Retrospectively, 158 consecutive patients with end-stage HF underwent orthotopic HT between January 2009 and June 2013 were analyzed. Of these, we excluded 3 patients with total HT. The study group was divided into modified technique (n=37) or conventional technique (n=118). A total of 113 patients (modified: n=29, conventional: n=84) were examined with cardiac CT. Discrepancy in the size of the vena cava compared with that of the anastomosis site was assessed. There was no significant difference in the complication and survival rates. There was 1 incident of moderate-to-severe tricuspid valve regurgitation in the modified group (n=1, 2.7%). Both the SVC ratio (1.07±0.13 vs. 1.28±0.32, P=0.001) and IVC ratio (1.06±0.07 vs. 1.13±0.19, P=0.009) were higher in the conventional group, which meant more stenotic imaging findings were observed in the conventional group.

CONCLUSIONS

Orthotopic HT with modified bicaval anastomosis is an attractive alternative with easy orientation and equivocal outcomes.

Impact of Coronary Artery Calcification in the Donor Heart on Transmitted Coronary Artery Disease in Heart Transplant Recipients

BACKGROUND

Coronary artery disease (CAD) after heart transplantation (HTx) develops as a combination of donor-transmitted coronary atherosclerosis (DTCA) and cardiac allograft vasculopathy. Assessing donor CAD before procurement is important. Because coronary artery calcification (CAC) is a predictor for CAD, donor-heart CAC is usually evaluated to estimate the risk of donor CAD. The usefulness of CAC for predicting DTCA, however, is not known. Methods and Results: Sixty-four HTx recipients whose donor underwent chest computed tomography before procurement or ≤2 weeks after HTx and who underwent coronary angiography and intravascular ultrasound (IVUS) ≤3 months after HTx were enrolled. Eight patients had CAC (CAC group) and 56 patients did not have CAC (no-CAC group). Patients in the CAC group were significantly older and had a higher prevalence of maximum intimal thickness (MIT) of the coronary artery ≥0.5 mm at initial IVUS than patients in the no-CAC group (100% vs. 55%, P=0.02). Adverse cardiac events and death were not significantly different. Everolimus tended to be used more often in the CAC group.

CONCLUSIONS

Donor-heart CAC is a significant predictor for MIT of the coronary artery ≥0.5 mm after HTx. The presence of CAC, however, is not associated with future cardiac events. The higher prevalence of everolimus use in the CAC group may have affected the results.

Early Result of Heart Transplantation in Japan: Osaka University Experience

Since the new organ transplantation law was established in 1997, 17 heart transplantations have been performed in Japan, 7 of which were carried out at Osaka University Hospital. Recipient diagnosis was dilated cardiomyopathy in 2, dilated phase of hypertrophic cardiomyopathy in 4, and post-myocarditis cardiomyopathy in 1. Ages ranged from 8 to 49 years with a mean of 35.3 years. Five patients were bridged with a left ventricular assist device. The waiting period was 182–977 days (mean, 643 days). There was no early or late death during follow-up of 1–4.8 years. Under a standard triple-drug regimen using mycophenolate, there were 3 rejection episodes greater than grade 3 in 2 patients, and humoral rejection requiring plasmapheresis in one. A young boy whose donor was a hemodynamically compromised adult developed neurological sequelae after resuscitation following ventricular tachycardia. All patients were discharged and went back to work or their regular daily life. Although the donor shortage is still severe in Japan, the resumption of heart transplantation has been satisfactory, and left ventricular assist devices have played a crucial role.

Heart transplantation in Japan: a critical appraisal for the results and future prospects

As of September 30, 2011, a total of 113 patients with end-stage heart failure underwent heart transplantation in Japan, and the early and late (10 years) survival rates appear better than those reported in 2011 by the Registry of the International Society of Heart and Lung Transplantation (ISHLT). Among the risk factors determining survival, use of both left ventricular assist devices (LVADs) during the pretransplant care and marginal donor hearts increased the risk while factors favoring survival included younger adult recipients and fewer patients with ischemic cardiomyopathy; factors noted in Japanese patients in comparison with those registered in the ISHLT report. Although only a few patients have reached 10 years follow-up, so far none has died or required retransplantation due to cardiac allograft vasculopathy (CAV). CAV may develop later in Japanese heart transplant patients than in those of mixed inter-ethnic transplants. Recently, survival rates with newer LVADs have dramatically improved and therefore, selection criteria for the permanent or destination use of an LVAD or for heart transplantation require further evaluation, depending upon the various factors in candidates with profound heart failure.

Anatomy of the cardiac nervous system with clinical and comparative morphological implications

Unlike autonomic nervous preservation in other surgeries for improving patient quality of life, autonomic cardiac nervous system (ACNS) preservation has been neglected in cardiovascular surgery because of technical difficulties and other unsolved issues. Because such ACNS preservation in cardiovascular surgery is anticipated in the future, detailed anatomical investigation of the human ACNS is required. Therefore, we have conducted morphological studies of the ACNS from macroscopic, clinical, and evolutionary anatomical viewpoints. In this study, I review detailed anatomical studies of the human ACNS together with their clinical implications. In addition, the evolutionary comparative anatomical significance of primate ACNS is also summarized to help understand and translate the findings of functional experiments to humans. These integrated findings will be the subject of a future study unifying molecular embryological and anatomical findings to clarify cardiac functions based on functional animal experiments, clinical applications such as improving surgery techniques and individual order-made surgery in cardiac surgery, and for future evaluation in regenerative medicine.

Hemodynamic and echocardiographic evaluation of orthotopic heart transplantation with the modified bicaval anastomosis technique

BACKGROUND

The purpose of this study was to evaluate the hemodynamic and echocardiographic function of hearts transplanted with the modified bicaval anastomosis technique (mBCAT).

METHODS AND RESULTS

Twenty consecutive patients (14 males, 6 females, age range 14-61 [41.3 +/-11.5 years]) were evaluated 3.4 +/-2.2 years after heart transplantation using the mBCAT. All patients were in status I on the waiting list, and 18 (90%) had had a left ventricular assist device. The donor age was 39 +/-12 years. Triple immunosuppressive regimen and cardiac biopsy were routinely performed. There was no hospital mortality. One death occurred 4.2 years after the operation because of bone marrow dysplasia and infection. The 8-year survival was 89% (95% confidence interval: 0.43-0.98). All the hemodynamic variables returned to the normal range. Low right atrial pressure (3.2 +/-1.5 mmHg) and low pulmonary wedge pressure (6.7 +/-2.1 mmHg) were associated with an excellent cardiac index (3.9 +/-0.7 L . min(-1) . m(-2)). Echocardiography revealed an excellent late peak velocity (52 +/-19 cm/s) and an E/A ratio (1.4 +/-0.6) of tricuspid flow. The grade (0-4) of tricuspid regurgitation averaged 1.5 +/-0.8.

CONCLUSIONS

Hemodynamic and echocardiographic results for mBCAT were excellent. The 8-year survival was 89% with all surviving patients in New York Heart Association class I. The mBCAT is easy to perform and further facilitates cardiac transplantation.

Surgical advances in heart and lung transplantation

The successes of thoracic transplantation have led to the expansion of indications and a subsequent growth in demand for a short supply of organs. In response to this disparity, the criteria for organ donation have been liberalized. Despite these difficult challenges, with advances in surgical techniques and perioperative care of both the donor and recipient, outcomes have continued to improve over time. This article focuses on the more recent surgical advances in donor selection and management, procurement and implantation, and the impact of these advances on patient outcome.