Long-Term Impact of Arteriovenous Fistula Ligation on Cardiac Structure and Function in Kidney Transplant Recipients: A 5-Year Follow-Up Observational Cohort Study.

Background: The long-term effects of arteriovenous fistula (AVF) ligation on cardiovascular structure following kidney transplantation remain uncertain. A prospective randomized, controlled trial (RCT) examined the effect of AVF ligation at 6 months on cardiovascular magnetic resonance imaging (CMR)-derived parameters in 27 kidney transplant recipients compared with 27 controls. A mean decrease in left ventricular mass (LVM) of 22.1 g (95% CI, 15.0 to 29.1) was observed compared with an increase of 1.2 g (95% CI, -4.8 to 7.2) in the control group (P<0.001). We conducted a long-term follow-up observational cohort study in the treated cohort to determine the evolution of CMR-derived parameters compared with those documented at 6 months post-AVF ligation. Methods: We performed CMR at long-term follow-up in the AVF ligation observational cohort from our original RCT published in 2019. Results were compared with CMR at 6 months postintervention. The coprimary end point was the change in CMR-derived LVM and LVM index at long-term follow-up from imaging at 6 months postindex procedure. Results: At a median of 5.1 years (interquartile range, 4.7-5.5 years), 17 patients in the AVF ligation group were studied with repeat CMR with a median duration to follow-up imaging of 5.1 years (IQR, 4.7-5.5 years). Statistically significant further reductions in LVM (-17.6±23.0 g, P=0.006) and LVM index (-10.0±13.0 g/m2, P=0.006) were documented. Conclusions: The benefit of AVF ligation on LVM and LVM index regression appears to persist long term. This has the potential to lead to a significant reduction in cardiovascular mortality.

Development and implementation of an enhanced recovery after surgery protocol for renal transplantation.

BACKGROUND: Successful implementation of enhanced recovery after surgery (ERAS) in kidney transplantation requires multidisciplinary consultation, education and attention to protocol. This study discusses the process implementation pathway of the ERAS protocol and its outcome. METHODS: A standardized ERAS protocol was designed for the renal transplant recipient and implemented in July 2017. Data collected prospectively of recipients transplanted from July 2017 to December 2018 were compared to prospectively collected data of recipients who were transplanted prior to ERAS implementation from January 2016 to July 2017 from our renal database. The parameters of interest included length of stay, incidence of delayed graft function and readmission rate. RESULTS: There was no difference in the demographics and the incidence of delayed graft function across both groups, although subgroup analysis suggested a significantly lower incidence of delayed graft function with kidneys donated after circulatory death in the cohort that were managed by the ERAS protocol. The median length of stay for patients on the ERAS protocol was 5 days (range 3-16 days). This was 2 days shorter than the median length of stay for patients not on the ERAS protocol (7 days; range 5-14, P < 0.001). This statistically significant difference in length of stay was consistent across all donor subgroups (living donor, donor after cardiac death and donation after brainstem death). Seventy-nine percent of the patients on the ERAS protocol were discharged on post-operative day 4. CONCLUSION: An ERAS protocol for renal transplant patients is feasible. Our data show that successful implementation of ERAS in kidney transplantation is possible and results in significant cost savings due to shorter length of stay.

Effects of Arteriovenous Fistula Ligation on Cardiac Structure and Function in Kidney Transplant Recipients.

BACKGROUND: Cardiovascular morbidity and mortality remain high in recipients of a kidney transplant. The persistence of a patent arteriovenous fistula (AVF) after transplantation may contribute to ongoing maladaptive cardiovascular remodeling. The ability to reverse this maladaptive remodeling by ligation of this AVF is unknown. We conducted the first randomized controlled trial to evaluate the effect of AVF ligation on cardiac structure and function in stable kidney transplant recipients. METHODS: In this randomized controlled trial, kidney transplant recipients (>12 months after transplantation with stable graft function) were randomized to AVF ligation or no intervention. All participants underwent cardiac magnetic resonance imaging at baseline and at 6 months. The primary outcome was the change in left ventricular (LV) mass. Secondary outcomes included changes in LV volumes, left and right atrial areas, LV ejection fraction, NT-proBNP (N-terminal pro-B-type natriuretic peptide) levels, cardiac output/index, brachial flows (ipsilateral to AVF), and pulmonary artery velocity. RESULTS: A total of 93 patients were screened, of whom 64 met the inclusion criteria and were randomized to the AVF ligation (n=33) or control (n=31) group. Fifty-four participants completed the study: 27 in the AVF ligation group and 27 in the control group. On the second cardiac magnetic resonance scan, a mean decrease of 22.1 g (95% CI, 15.0-29.1) was observed in LV mass in the AVF ligation group compared with a small increase of 1.2 g (95% CI, -4.8 to 7.2) in the control group ( P<0.001). Significant decreases in LV end-diastolic volumes, LV end-systolic volumes, cardiac output, cardiac index, atrial volumes, and NT-proBNP were also seen in the AVF closure group ( P<0.01). No significant changes were observed in LV ejection fraction ( P=0.93) and pulmonary artery velocity ( P=0.07). No significant complications were noted after AVF ligation. No changes in estimated glomerular filtration rate or systolic and diastolic blood pressures were observed between cardiac magnetic resonance scans. CONCLUSIONS: Elective ligation of patent AVF in adults with stable kidney transplant function resulted in clinically significant reduction of LV myocardial mass. CLINICAL TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Registry URL: https://www.anzctr.org.au . Unique Identifier: ACTRN12613001302741.

Characterization of cardiac remodeling in a large animal "one-kidney, one-clip" hypertensive model.

OBJECTIVE: The aim of this study is to characterize cardiac remodeling in a large animal model of hypertension. METHODS: 23 sheep were subjected to unilateral nephrectomy followed by clamping of the remaining renal artery to 60% ("one kidney-one clip", 1K1C) 3 weeks later. Blood pressure (BP) was monitored invasively over 73+/-28 days. Cardiac function was assessed with magnetic resonance imaging and compared with 12 size-matched controls. Detailed atrial histopathological analysis was performed. RESULTS: In the 1K1C animals, BP rose from baseline to reach a plateau by 4 weeks (systolic BP: 107+/-12 to 169+/-27, diastolic BP: 71+/-10 to 118+/-29 mmHg, both p< 0.0001); cardiac hypertrophy was significant when compared with controls with increased left ventricular weight [left ventricular (LV)/body wt: 2.7+/-0.5 vs 2.1+/-0.2 g/kg, p=0.01] as well as bi-atrial enlargement (right atrial, RA: 22.9+/-4.9 vs 15.7+/-2.8g, p=0.003; left atrial, LA: 35.5+/-6.7 vs 20.9+/-4.1g, p=0.0003); cardiac magnetic imaging demonstrated significantly increased LA volumes (end-diastolic volume: 42.9+/-6.8 vs 28.7+/-6.3 ml, p< 0.0001) and reduced LA ejection fraction (24.1+/-3.6 vs 31.6+/-3.0%, p=0.001) while LV function was relatively preserved (42.3+/-4.7 vs 46.4+/-4.1%, p=0.1); degeneration and necrosis of atrial myocytes were evident with increased atrial lymphocytic infiltration and interstitial fibrosis. CONCLUSIONS: The ovine 1K1C model produces reliable and reproducible hypertension with demonstrable cardiac end-organ damage.

Transection of the renal pelvis by endocatch bag during laparoscopic donor nephrectomy.

A case of inadvertent transection of the renal pelvis by the Endocatch bag during laparoscopic donor nephrectomy is reported. This is the second reported injury resulting from the Endocatch bag. We have successfully managed the injury with continuing good renal function after 3 years. The aim of this report is to increase the awareness of this potential complication and how it can be prevented.

Laparoscopic live donor nephrectomy.

BACKGROUND: The demand for renal transplants is greater than the available kidneys. Live donation is one way of increasing the supply. Laparoscopic removal of the donor kidney appears to reduce morbidity for the donors. Some who are hesitant because of the morbidity associated with open nephrectomy are willing to consider the laparoscopic donor nephrectomy. METHODS: Laparoscopic donor nephrectomy was offered to all but three donors since the commencement of the programme in 1997. Data were collected both prospectively and retrospectively for the first 120 donors. Venous and arterial anatomy was assessed preoperatively by computed tomographic angiography. RESULTS: All but four donor procedures were completed laparoscopically. Three of these were for bleeding that could not be safely controlled laparoscopically and the fourth was a planned conversion to deal with the renal vessels, in the first right nephrectomy. Two kidneys were lost due to arterial thrombosis and two underwent segmental infarction after the loss of one of two or three separately anastomosed vessels. Three recipients had delayed function and two of them required dialysis postoperatively. Other minor complications occurred but were uncommon. CONCLUSIONS: Laparoscopic live donor nephrectomy is safe for the donor and the transplant kidney. It offers the advantage of decreased morbidity for the donor, with a shorter hospital stay, earlier return to normal activity and, for some, early return to work.

Segmental infarction with graft dysfunction: an emerging syndrome in renal transplantation?

BACKGROUND: Segmental allograft infarction is a poorly characterized complication following renal transplantation. The present study was undertaken with the goal of defining the incidence, clinical characteristics, pathogenesis, and prognosis of this entity. METHODS: A retrospective study was performed, reviewing the renal scans performed on all renal transplant recipients at our institution, from January 1997 to January 2000. Segmental infarction was diagnosed on the basis of a significant elevation in lactate dehydrogenase (>500 U/l) together with a photopenic perfusion defect. In these patients, graft characteristics, operative details, clinical course, and long-term outcomes were evaluated. RESULTS: Segmental infarction was identified in 13 of 277 consecutive renal transplant recipients (4.7%). In nine recipients the onset of infarction occurred within 24 h after transplantation. All received marginal grafts, and in five recipients the transplant operation was complicated by major blood loss. Eight of these recipients exhibited primary non-function, or developed dialysis-dependent renal failure after the onset of infarction. In four patients, the onset of infarction occurred after 24 h (35 h to 10 days). One recipient demonstrated primary non-function, and renal function deteriorated after the onset of infarction in the remaining three. Overall, long-term graft function was impaired. Two allografts never functioned, and six recipients had nadir creatinine clearances below 60 ml/min. CONCLUSIONS: The pathogenesis of segmental infarction appears to be multi-factorial, reflecting the combination of an initiating anatomic lesion and potentiating thrombogenic milieu. Segmental infarction typically occurs in the early postoperative period, and prompt diagnosis is difficult to obtain. In view of this, prophylactic heparin may be warranted for those at highest risk. There was no correlation between the infarct area and the graft function, and the long-term graft function is compromised out of proportion to the extent of parenchymal loss. This finding highlights the role of predisposing factors, particularly marginal graft quality, in determining the functional outcome. Segmental infarction may be more frequently encountered as cadaveric organ shortages encourage greater use of marginal donor kidneys.

Uncommon Complications of Renal Transplantation.

As a result of advances in surgical technique and immunosuppressive therapy, the incidence and the consequences of post-transplant surgical complications has decreased. However, surgical complications still cause considerable morbidity and test the skills of the surgical team. Several reviews have been published analyzing the incidence of these complications and the management strategies employed to correct them. We report some uncommon or rare complications encountered in our unit after the introduction of low-dose steroids or steroid-free immunosuppressive protocols.