Risk Factors for Graft Loss Due to Acute Vascular Complications in Adult Renal Transplantation Using Grafts Without Vascular Anomalies

Anastomotic Pseudoaneurysm in Kidney Transplant: A Challenging Management for a Rare Entity

PURPOSE

Anastomotic pseudoaneurysms of transplanted kidneys are a very rare complication encountered in less than 1% of cases. They may be devastating, leading to functional impairment, kidney transplantectomy, or death. Treatment has not been standardized, with open surgical repair considered the safest procedure even if it is often complicated by bleeding and graft loss. The purpose of this case report is to describe an endovascular treatment of this condition, consisting of the combination of coil embolization and arterial stenting.

CASE REPORT

A 61-year-old woman developed an anastomotic pseudoaneurysm 2 months after kidney transplantation, causing acute kidney injury related to ab-extrinsic stenosis of the transplant renal artery (TRA) and external iliac artery. The pseudoaneurysm was successfully treated by coil embolization, and the arterial patency was restored by the stenting of TRA and external iliac artery. The patient completely recovered kidney function, and after a 6-month-follow-up, creatinine values were stable with normal renal perfusion.

CONCLUSION

Endovascular repair through coil embolization and TRA stenting can be a safe and effective option to treat anastomotic pseudoaneurysm in kidney transplant.

Successful Kidney Transplantation From A Donor With Inherited Thrombophilia: A Case Report

Inherited thrombophilia is a blood clotting disorder caused by genetic mutations of specific coagulation plasma factors. It is a well-established predisposing factor for venous as well as arterial thromboembolism. Thromboembolic events with renal involvement in patients with inherited thrombophilia are possible but relatively rare. On the other hand, vascular complications, including renal artery and vein thrombosis, are the main causes of early graft loss after kidney transplantation. Furthermore, there is evidence that inherited thrombophilia has a role in chronic kidney disease development. Although there are data on kidney transplantation of recipients with inherited thrombophilia, to the best of our knowledge there are no reports on kidney donation from patients with thrombophilia in the English literature. We present 2 cases of successful kidney transplantation from the same donor with inherited thrombophilia.

Description and Outcomes of Three Different End-to-Side Microsurgical Techniques for the Anastomosis of Accessory Renal Artery With the Dominant Renal Artery in Kidney Transplantation

BACKGROUND

In this study, we compared the outcomes of three different surgical microscope-assisted end-to-side anastomosis techniques between the dominant and accessory renal arteries during living donor kidney transplant.

METHODS

The demographics, serum creatinine levels, warm and cold ischemia times, rate of complications, and incidence of delayed graft function of 135 kidney recipients were analyzed according to the type of arterial anastomosis. Group A (n = 98) had one dominant renal artery (DRA) with one end-to-side anastomosis to the external iliac artery (EIA) using a surgical microscope. Group B (n = 17) had one DRA plus one accessory renal artery (ARA) with two separate end-to-side anastomoses to the EIA using a surgical microscope. Group C (n = 20) had one DRA with end-to-side anastomosis to the EIA and one ARA with an ex vivo on-bench end-to-side anastomosis to the DRA using a surgical microscope.

RESULTS

Compared with groups A and B, the cold ischemia time and the rate of delayed graft function were significantly higher in group C (P ≤ .001). At 6 months after transplant, group B demonstrated a higher creatinine value (2.40 ± 3.41 mg/dL) than group A and group B (P = .032). Also, the decrease in creatinine at postoperative month 6 was limited in group B as compared with groups A and C.

CONCLUSIONS

An end-to-side anastomosis between ARA (group B) and DRA (group A) of the kidney graft using a surgical microscope on the bench ex vivo results in superior outcomes. Single arterial anastomosis techniques are associated with a better function in a 6-month follow-up than two separate arterial anastomoses.

Multiparametric ultrasound findings in acute kidney failure due to rare renal cortical necrosis

Renal cortical necrosis (RCN) is a rare cause of acute kidney failure and is usually diagnosed on the basis of characteristic enhancement patterns on cross-sectional imaging. Contrast-enhanced ultrasound (CEUS) offers benefits in patients with kidney failure in the clinical setting including the use of a nonnephrotoxic intravascular contrast agent and the fact that it can be performed at the bedside in critical cases. Therefore, the aim of this study is to investigate whether CEUS can reliably identify typical imaging features of RCN. We retrospectively analyzed 12 patients with RCN examined in our department and confirmation of the diagnosis by either histopathology, other contrast-enhanced cross-sectional imaging tests, and/or CEUS follow-up. Assessed parameters in conventional US were reduced echogenicity, loss of corticomedullary differentiation, length and width of kidney, hypoechoic rim, resistance index and in CEUS delayed wash-in of contrast agent (> 20 s), reverse rim sign, maximum nonenhancing rim and additional renal infarction. Furthermore, imaging features in RCN were compared with the findings in renal vein thrombosis (RVT), among them echogenicity, corticomedullar differentiation, hypoechoic rim, RI value, delayed cortical enhancement, total loss of cortical perfusion and enhancement of renal medulla. All 12 patients showed the reverse rim sign, while a hypoechogenic subcapsular rim was only visible in four patients on B-mode ultrasound. A resistance index (RI) was available in 10 cases and was always less than 1. RI was a strong differentiator in separating RVT from RCN (RI > 1 or not measurable due to hypoperfusion as differentiator, p = 0.001). CEUS showed total loss of medullary enhancement in all cases of RVT. With its higher temporal resolution, CEUS allows dynamic assessment of renal macro- and microcirculation and identification of the typical imaging findings of RCN with use of a nonnephrotoxic contrast agent.

Hypothermic machine perfusion can safely prolong cold ischemia time in deceased donor kidney transplantation. A retrospective analysis on postoperative morbidity and graft function

In deceased donor kidney transplantation (KT), a prolonged cold ischemia time (CIT) is a negative prognostic factor for KT outcome, and the efficacy of hypothermic machine perfusion (HMP) in prolonging CIT without any additional hazard is highly debated. We conducted a retrospective study on a cohort of 154 single graft deceased donor KTs, in which a delayed HMP, after a preliminary period of static cold storage (SCS), was used to prolong CIT for logistic reasons. Primary outcomes were postoperative complications as well as 1 year graft survival and function. 73 cases (47.4%) were managed with HMP and planned KT, while 81 (52.6%) with SCS and urgent KT. The median CIT in HMP group and SCS group was 29 hour:57 minutes [27-31 hour:45 minutes] and 11 hour:25 minutes [9-14 hour:30 minutes], respectively (P < .001). The period of SCS in the HMP group was significantly shorter than in the SCS group (10 vs. 11 hour:25 minutes, P = .02) as well as the prevalence of expanded criteria donors was significantly higher (43.8% vs. 18.5%, P < .01). After propensity score matching for these two baseline characteristics, the HMP and SCS groups showed comparable outcomes in terms of delayed graft function, vascular, and urologic complications, infections, and episodes of graft rejection. At 1 year follow-up, serum creatinine levels were comparable between the groups. Therefore, the use of HMP to prolong the CIT and convert KT into a planned procedure seemed to have an adequate safety profile, with outcomes comparable to KT managed as an urgent procedure and a CIT nearly three time shorter.

Predictive Value of Intraoperative Doppler Flowmetry for Delayed Graft Function in Kidney Transplantation: A Pilot Study

BACKGROUND

The delayed graft function (DGF) in kidney transplantation (KT) is a risk factor for long-term poor graft survival. The pathogenesis is multifactorial but mainly related to an ischemia-reperfusion injury. However, the graft hemodynamics have been recently identified as a key aspect for early DGF risk assessment and potential therapeutic intervention.

METHODS

A pilot study on 20 single kidney grafts from donor after brain death with intraoperative measurement of graft arterial flowmetry, 30 minutes after reperfusion. Exclusion criteria were grafts with multiple arteries or severe atherosclerosis of the recipient's external iliac artery.

RESULTS

KT recipients with DGF (n = 4, 20%) were homogenous with controls (n = 16) in terms of cold ischemia time, donor age, recipients' hemodynamic parameters, renal artery, and recipients' external iliac artery diameters. Nonetheless, at transplant, the kidney grafts that developed DGF were characterized by a significantly higher renal artery resistive index (DGF vs no-DGF 0.96 ± 0.04 vs 0.77 ± 0.13, P = .02), as well as lower flow extraction rate (24.8% ± 11.8 vs 59.2% ± 21.1, P < .01).

CONCLUSIONS

Intraoperative arterial graft flowmetry seems to be an effective tool to identify grafts at high risk of DGF.

Effects of Delayed Hypothermic Machine Perfusion on Kidney Grafts with a Preliminary Period of Static Cold Storage and a Total Cold Ischemia Time of Over 24 Hours

Background

Hypothermic machine perfusion (HMP) appears to exert a reconditioning effect on the ischemic damage of kidney grafts. However, some concerns still remain about its real effectiveness when it is delayed after a preliminary period of static cold storage (SCS) or with prolonged overall cold ischemia time (CIT).

Material/Methods

The effect of HMP on hemodynamic, metabolic, histological and ultrastructural features of grafts was investigated in 21 single-kidney grafts treated with a delayed HMP after SCS and with a total CIT of over 24 h.

Results

The mean CIT, SCS, and HMP times were 29 h, 12 h, and 18 h, respectively. Longer SCS was associated with higher vascular resistance and lower arterial flow. In the pre- vs. post-HMP comparison, a significant decrease in arterial resistances and increase of flow were recorded. The hemodynamic improvement was independent of HMP duration. The perfused grafts retained some metabolic activity, with a statistically significant decrease of pH, pO2, and glucose levels, and increase of lactates in the perfusion liquid, by the end of HMP. Longer SCS was associated with higher pH and greater pO2 decrease during HMP. Light microscopy and transmission electronic microscopy revealed no significant variations in nuclear, cytoplasmic, or ultrastructural damage. SCS, HMP, and CIT were not identified as risk factor for delayed graft function or rejection.

Conclusions

A delayed and extended HMP can recover the graft hemodynamic function, maintain some metabolic activity, and stabilize the accumulated ischemic damage due to a preliminary SCS.