Donor risk factors for renal graft thrombosis

Case report: Application of nonsurgical method in saving transplant renal vein thrombosis caused by acute diarrhea

Transplant renal vein thrombosis is a rare complication after kidney transplantation, which can seriously threaten graft survival. Though the measures like thrombolytic therapy or operative intervention could be taken to deal with this complication, allograft loss is the most common outcome. Thus, early finding as well as decisive intervention is crucial to saving the graft. Here we present a 46-year-old male patient who underwent kidney transplantation from a cadaveric donor who developed a transplant renal venous thrombosis induced by acute diarrhea more than 1 year after renal transplantation with an initial symptom of sudden anuria and pain in the graft area. Subsequently, serum creatinine levels increased to 810.0 μmol/L. Pelvic CT showed increased vascular density of the transplanted kidney, and contrast-enhanced ultrasound confirmed venous thrombosis. The patient was treated with heparin sodium alone and diuresis gradually resumed. After more than 1 year of follow-up, serum creatinine returned to the baseline level prior to thrombosis. Our case indicates that quick ancillary examination and treatment without hesitation would be indispensable in rescuing allografts with renal vein thrombus. Unfractionated heparin can be recommended as an effective treatment for mid-long-term renal transplantation patients with renal vein thrombosis.

Association of the Calcification Score of the Abdominal Aorta, Common Iliac, and Renal Arteries with Outcomes in Living Kidney Donors

BACKGROUND

Vascular calcification is an ever-more-common finding in protocoled pre-transplant imaging in living kidney donors. We intended to explore whether a connection could be found between the Agatston calcification score, prior to kidney donation, and post-donation renal function.

METHODS

This is a retrospective analysis of 156 living kidney donors who underwent living donor nephrectomy between January 2010 and December 2016. We quantified the total calcification score (TCaScore) by calculating the Agatston score for each vessel, abdominal aorta, common iliac, and renal arteries. Donors were placed into two different groups based on their TCaScore: <100 TCaScore group and ≥100 TCaScore group. The relationship between TCaScore, 1-year eGFR, proteinuria, and risk of 1 measurement of decreased renal function (eGFR < 60 mL/min/1.73 m²) over 5 years of follow-up was investigated.

RESULTS

The ≥100 TCaScore group consisted of 29 (19%) donors, with a median (interquartile range) calcification score of 164 (117-358). This group was significantly older, 56.7 ± 6.9 vs. 45.5 ± 10.6 (p < 0.001), had a higher average BMI (p < 0.019), and had a lower preoperative eGFR (p < 0.014). The 1-year eGFR was similarly diminished, 69.9 ± 15.7 vs. 76.3 ± 15.5 (p < 0.048), while also having an increased risk of decreased renal function during the follow-up, 22% vs. 48% (p < 0.007).

CONCLUSIONS

Our study, through univariate analyses, found a relationship between a TCaScore > 100, lower 1-year eGFR, and decreased renal function in 5 years. However, a higher-than-expected vascular calcification should not be an excluding factor in donors, although they may require closer monitoring during follow-up.

Utility of thrombophilia screening in pediatric renal transplant recipients

Thrombosis after kidney transplantation may result in catastrophic outcomes, including graft loss. Thrombophilia has been implicated in post-transplant thrombosis; data, however, are inconclusive on the impact of acquired and inherited thrombophilia and resultant thrombosis in renal graft recipients. We aimed to evaluate whether identifying children with thrombophilia during the pretransplant evaluation predicted post-transplant outcomes. We reviewed 100 kidney transplants performed in 100 children, aged 1-18 years, in a single-center retrospective study. Routine pretransplant comprehensive thrombophilia evaluation was completed. Thrombophilia was demonstrated in 36% patients (N = 36). TEs occurred in 11 patients before kidney transplant. Low PS and antithrombin were found in 9/86 (10.5%) and 2/89 (2.2%) children, respectively. Heterozygosity for FLV and PGM were found in 5/81 (6.2%) and 1/93(1.1%) children, respectively. A post-transplant thrombotic event occurred in 10 children (10%); six involved the renal transplant. The association between a history of a pretransplant thrombotic event and post-operative renal graft thrombosis approached, but did not reach significance (P = 0.071). There was no association between preoperative screening abnormalities and post-operative TEs. Graft loss due to a thrombotic event occurred in two patients; none had underlying thrombophilia. Our data suggest that the utility of universal, comprehensive preoperative thrombophilia testing is not beneficial in determining risk of post-operative graft thrombosis. Thrombophilia testing may be considered in a select population with a history of pretransplant thrombotic event.

Successful salvage of allograft dysfunction triggered by transplant renal vein thrombosis immediately after kidney transplantation: a case report

Background

Transplant renal vein thrombosis (TRVT) is a severe vascular complication and is caused by various factors, including recipient factors, donor factors, immunosuppression regimens, and surgical techniques. Despite adequate interventions, including thrombolytic therapy or surgical thrombectomy, successful salvage of the allograft is often difficult. We observed a case of TRVT induced by compression of the renal vein immediately after intraoperative abdominal closure.

Case presentation

A 41-year-old male underwent ABO-compatible living kidney transplantation. The donor was his 45-year-old sister, and her right kidney was donated. The allograft had a single artery and vein. One of the preoperative recipient problems was obesity (body mass index, 33.4 kg/m²). Intraoperative Doppler ultrasonography (US) revealed sufficient blood flow throughout the allograft, and urine output was also observed. After surgery, hematuria was observed; the urine output decreased and serum creatinine levels increased to 7.0 mg/dL. Doppler US showed a decrease in diastolic flow and an elevated resistive index, which were similar findings to those noted in acute rejection. Although steroid pulse therapy was initiated, allograft dysfunction was worsening. On postoperative day 4, surgical exploration revealed TRVT; consequently, thrombectomy was performed. The urine output increased, and serum creatinine levels decreased to 1.8 mg/dL. The cause of TRVT development may be that the transplant renal vein was relatively short, due to the right kidney being compressed by surrounding tissues after abdominal closure, and that TRVT was gradually developing due to stagnant blood flow.

Conclusion

Although TRVT is induced by multiple factors, an accurate diagnosis is often difficult. Understanding these factors, including obesity, and considering TRVT as a cause of allograft dysfunction are important during the pre-, peri-, and postoperative periods. Knowledge of TRVT can lead to early and accurate diagnosis and intervention, resulting in better outcomes for the patients with allograft dysfunction.

Abdominal Aortic Calcification in Living Kidney Donors

OBJECTIVE

This study assesses the association between abdominal aortic calcification (AAC) and renal function of living kidney donors and evaluate AAC as a surrogate marker for nephrosclerosis.

METHODS

Between January 2010 and March 2013, 287 donors who underwent living donor nephrectomy were enrolled. We analyzed computed tomography angiographies and quantified AAC scores by calculating the Agatston score for the abdominal aorta. The donors were stratified into the non-AAC group (AAC score = 0; n = 238) and the AAC group (AAC score >0; n = 49). The relationship between AAC and perioperative estimated glomerular filtration rate was analyzed. For the 180 donors consenting to implantation biopsy, the nephrosclerosis score was defined as the sum of abnormalities, including glomerulosclerosis, tubular atrophy, interstitial fibrosis, and arteriosclerosis.

RESULTS

The mean AAC score was 185.5 ± 263.3 in the AAC group. The AAC group was older than the non-AAC group (51.1 ± 6.1 vs 37.9 ± 11 years; P < .001). Perioperative renal function was not different between the 2 groups. However, among the AAC group, donors with an AAC score of >100 were associated with delayed renal function recovery (P = .035). Donors with AAC were more likely to have glomerulosclerosis (50.0% vs 29.1%; P = .022), tubular atrophy (62.5% vs 33.1%; P = .002), and a higher nephrosclerosis score (P = .002).

CONCLUSIONS

Living donors with an AAC score of >100 require close observation because they have a higher probability of delayed renal function recovery after donation. AAC is associated with nephrosclerosis in healthy adults.

Identification of risk factors for vascular thrombosis may reduce early renal graft loss: a review of recent literature

Renal graft survival has improved over the past years, mainly owing to better immunosuppression. Vascular thrombosis, though rare, therefore accounts for up to one third of early graft loss. We assess current literature on transplantation, identify thrombosis risk factors, and discuss means of avoiding thrombotic events and saving thrombosed grafts. The incidence of arterial thrombosis was reported to 0.2–7.5% and venous thrombosis 0.1–8.2%, with the highest incidence among children and infants, and the lowest in living donor reports. The most significant risk factors for developing thrombosis were donor-age below 6 or above 60 years, or recipient-age below 5-6 years, per- or postoperative hemodynamic instability, peritoneal dialysis, diabetic nephropathy, a history of thrombosis, deceased donor, or >24 hours cold ischemia. Multiple arteries were not a risk factor, and a right kidney graft was most often reported not to be. Given the thrombosed kidney graft is diagnosed in time, salvage is possible by urgent reoperation and thrombectomy. Despite meticulous attentions to reduce thrombotic risk factors, thrombosis cannot be entirely prevented and means to an early detection of this complication is desirable in order to save the kidneys through prompt reoperation. Microdialysis may be a new tool for this.

Risk factors for early renal graft thrombosis: a case-controlled study in grafts from the same donor

Renal graft thrombosis is an important cause of early graft loss. In a case-controlled analysis including only thrombosed kidneys and their counterparts from the same donors, we found that the right kidney as opposed to the left kidney was the only risk factor for early graft vascular thrombosis. No other recipient, donor, or perioperative factor was significantly associated with the complication. Our findings suggested that implantation of a right kidney might be followed by prophylactic anticoagulant or antiaggregant therapy.