# Management of Transplant Renal Artery Pseudoaneurysm and Literature Review

Authors: Luke Anders; Rachel Stephens; Melissa Laub; Rushay Amarath-Madav; Ahmad Mirza; Muhammad Irfan Saeed
Journal: Case Reports in Transplantation
 (2022)

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## Abstract

Renal transplantation is the ultimate treatment for end-stage renal disease patients. However, vascular complications can impact renal allograft outcomes. Extrarenal pseudoaneurysms (EPSA) are a rare complication occurring in 1% of transplant recipients. We report a case series of extrarenal pseudoaneurysm after kidney transplant with different clinical presentations and management strategies. Given the rarity of EPSA, literature describing this complication is limited to single case reports or small retrospective case series. We also provide an up-to-date review of 76 articles on mycotic, bacterial, and idiopathic EPSAs. Allograft removal is considered standard treatment, but new endovascular alternatives may allow allograft salvage. EPSA should be managed with a multidisciplinary approach. Surveillance with renal ultrasound is recommended in patients considered high risk.


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## Body

## 1. Introduction

Vascular complications, which have an incidence rate of 6-30% after a kidney transplant, can impact allograft and patient outcomes [1]. Vascular complications include renal artery stenosis, arterial/venous thrombosis, arteriovenous fistulas, and renal artery pseudoaneurysms [1]. Intrarenal pseudoaneurysms are most commonly secondary to percutaneous kidney biopsy, infection, or technical error but usually resolve spontaneously with time, despite a 5% occurrence rate [2]. Extrarenal pseudoaneurysms (EPSAs) carry an incidence rate of 1% and cause irreversible arterial destruction of the vessel wall; causes can include infectious and noninfectious etiologies [1, 3, 4]. Despite their rarity, EPSAs are a serious complication, which profoundly impact both graft and patient survival. Though small EPSAs can be closely observed, large or infected EPSAs are a clinical emergency. Rupture of the EPSA creates life-threatening bleeding, so allograft nephrectomy, either prophylactically or emergently, is the recommended treatment of choice [5–7]. Evidence-based care of this complication is limited to single case reports or small retrospective series. Here, we report three cases of infectious EPSA after kidney transplantation, including their wide-ranging clinical presentations, treatments, and outcomes (Table 1). Additionally, we present an up-to-date review of the literature to provide the reader with a multitude of examples of how this anomaly may present in practice (Table 2).Table 1
Summary of our three cases, including clinical presentations, treatments, and outcomes.
AgeTime since transplantOrganisms cultured in urine posttransplantOrganisms cultured in blood posttransplantDiagnosis on imagingOutcomeRecipient 1682.5 weeksPseudomonas aeruginosa (on admission)Pseudomonas aeruginosa (on admission)CTA: hematoma with active bleed from IPA of donor renal arteryNephrectomyRecipient 26927 weeksEnterococcus faecalis (on admission)Bacteroides (week 4)Enterococcus faecalis (on admission)Noncontrast CT:8×8 cm mass highly suspicious for blood components, seen in the same area of the pseudoaneurysm seen in his initial ultrasoundEndovascular exclusion via covered stentRecipient 3646 weeksVancomycin-resistantEnterococcus faecium and Candida tropicalis (week 1)Pseudomonas aeruginosa(week 5)Vancomycin-resistant Enterococcus faecium (week 6)N/AAngiography: large and small pseudoaneurysms arising from the proximal and midtransplant renal artery, respectivelyLarge PA: coil embolization+6×16 mm covered stentSmall PA: 6×16 mm covered stentTable 2
Review of literature on extrarenal pseudoaneurysms in the PubMed/MEDLINE and Google Scholar databases (1978–September 1, 2021). Tx: transplantectomy; SR: surgical repair; EVS: endovascular stenting; EVC: endovascular coiling; OBS: observation.
AuthorYearNInfectionInterval after transplantInterventionOutcomeBacterial pseudoaneurysms in literature reviewNelson198411/P. aeruginosa11 days1/Tx1/graft lossKumar200211/P. aeruginosa9 days1/Tx1/graft lossSaidi200422/P. aeruginosa—2/Tx2/graft lossEng200641/MRSA, C. difficile1/MRSA1/S. marcescens1/C. albicans—4/Tx4/graft loss2/deathFujikata200611/MRSA1.3 months1/OBS1/graft preservedNguan200611/S. aureus—1/Tx1/graft lossPoels and Riley200711/P. aeruginosa1.7 months1/EVS + thrombin1/graft preservedOrlando200922/P. aeruginosa11-21 days2/Tx2/deathBerglund201111/P. aeruginosa46 days1/SR1/graft preservedBuimer201211/E. coli14 months1/SR1/graft preservedKaabak201311/P. aeruginosa10 days1/SR1/graft preservedChandak201411/P. aeruginosa10 days1/SR1/graft preservedChe201411/E. coli4 months1/EVS1/graft preservedPatil201511/E. coli21 days1/EVS1/graft preservedBerger201722/P. aeruginosa3-15 days1/Tx1/EVS1/graft loss1/graft preservedChung201711/P. aeruginosa1 month1/Tx1/graft lossMycotic pseudoaneurysms in literature reviewPotti199811/C. albicans—1/Tx1/graft lossBattaglia200022/C. albicans17 days-3 months2/Tx2/graft lossCalvino200322/C. albicans—2/Tx2/graft lossGarrido200322/A. flavus1.5-4 months2/Tx1/death1/graft lossPeel200311/C. albicans1 month1/SR + EVC1/graft preservedLaouad200544/C. albicans9 days-3 months4/Tx3/graft loss1/deathZavos200532/C. albicans—2/Tx2/graft lossHenderson200711/C. albicans4 months1/Tx1/graft lossLiu200911/A. flavus12 months1/Tx1/graft lossOsman200911/C. albicans1.2 months1/EVS + Tx1/graft lossTaksin200911/C. albicans3 weeks1/Tx1/graft lossWang200934/A. flavus10 days-1.5 months4/Tx4/graft lossAkhtar201111/C. albicans—1/Tx1/graft lossLee201111/C. albicans2 months1/Tx1/graft lossMinz201122/A. flavus1-5 months2/Tx1/death1/graft lossPolat201111/C. albicans—1/Tx1/graft lossKountidou201211/C. albicans3 months1/SR1/graft preservedRam Reddy201222/A. flavus3-20 weeks2/Tx2/graft lossDebska-Slizien201522/C. albicans10-30 days2/Tx2/death after OPMadhav201511/C. albicans25 days1/SR1/graft preservedZhao201622/C. albicans14-21 days2/EVS + Tx2/graft lossLazarus201611/C. albicans47 days1/Tx1/graft lossLin201722/C. albicans14-32 days1/Tx1/SR1/graft loss1/graft preservedMinistro201722/C. albicans60-150 days2/SR2/graft preservedMixed pseudoaneurysms in literature reviewKyriakides197684/E. coli2/C. albicans2/P. aeruginosa1.5-6 months8/Tx1/SR2/death6/graft lossKoo199931/MRSA2/none2-3 months1/EVC1/Tx1/OBS1/graft loss2/graft preservedBracale2009121/E. coli2/C. albicans9/none13 days-49 months8/Tx3/EVS + Tx1/SR + replantation8/graft loss3/death after OP1/graft preservedBozkurt201021/C. albicans1/E. faecalis11-18 days2/Tx2/graft lossLeonardou201242/P. aeruginosa1/K pneumonia1/C. albicans3-15 months4/EVS + Tx4 graft lossSantangelo201362/C. albicans4/none1.5-10 months1/SR + replantation4/Tx1/EVS + Tx1/graft preserved5/graft lossPatrono201532/C. albicans1/P. aeruginosa12-25 days2/Tx1/SR2/graft loss1/graft preservedFananapazir201642/P. aeruginosa2/none2-12 weeks3/Tx1/EVC3/graft loss1/graft preservedLiu201852/A. baumannii2/C. albicans1/S. epidermidis9-21 days5/SR5/graft preservedIdiopathic pseudoaneurysms in literature reviewRenigers and Spigos197811/none28 days1/Tx1/graft lossBenoit198811/none6 months1/Tx1/graft lossKoo199933/none2-4 months1/Tx2/observation1/graft loss2/graft preservedReus200211/none2 months1/thrombin1/graft lossTaghavi200511/none72 months1/SR1/graft preservedZavos200522/none5 months2/EVS2/graft lossAsztalos200611/none6 months1/SR1/graft preservedFujita200611/none5 months1/EVS1/graft preservedSiu200611/none3 months1/EVS + thrombin1/graft preservedFornaro200711/none15 months1/thrombin1/graft preservedGravante200811/none6 months1/SR1/graft preservedOrlic200811/none2.5 months1/Tx1/graft lossSharron200911/none3 months1/SR + thrombin1/graft preservedAl-Wahaibi201011/none4 months1/SR1/graft preservedAkgul201111/none14 years1/EVC1/graft preservedFavelier201211/none36 months1/EVC and stent1/graft preservedSmeds201311/none72 months1/EVS1/graft preservedTshomba201511/none9 months1/EVS1/graft preservedArdita201511/none20 days1/SR1/graft preservedFarooqui201611/none2 months1/SR1/graft preservedTurunc201711/none1 month1/EVS1/graft preservedMarie201811/none5 months1/EVC1/graft preservedSharma201822/none14-24 months1/SR1/EVS2/graft preservedUgurlucan201811/none3 months1/EVC1/graft preservedHaijie202066/none—6/EVS3/graft loss3/graft preservedVijayvergiya202111/none—1/EVC and stent1/graft preservedXu202111/none6 months1/observation1/graft preserved


## 2. Case Presentation

### 2.1. Case 1 (Figure1)

Figure 1
Case 1 imaging, whose blood and urine cultures on admission grewPseudomonas aeruginosa. (a) Ultrasound on admission demonstrating normal LLQ transplant kidney with patent renal artery and vein without pseudoaneurysm. (b) Noncontrast CT A/P demonstrating slight interval increase in size of hematoma compared to prior imaging. No evidence of active bleeding. (c) CT angiogram demonstrating irregular, actively bleeding pseudoaneurysm arising from the transplant renal artery ~1.2 cm from the anastomosis. (d) Arteriogram demonstrating pseudoaneurysm with active contrast extravasation. A 6mm×22mm covered stent was placed successfully within the proximal transplant renal artery; however, persistent hemorrhage warranted emergent surgical management.
(a)(b)(c)(d)The patient was a 68-year-old male with end stage renal disease (ESRD) secondary to Wegener’s granulomatosis who received his second deceased donor kidney transplant (DDKT) in November 2019. His postoperative course was significant for delayed graft function secondary to acute tubular necrosis (ATN). On postoperative day (POD) 19, he presented to clinic with complaints of fatigue, chills, and rigors. He was diagnosed with urosepsis. Both blood and urine cultures on admission grewPseudomonas aeruginosa. Patient was started on broad spectrum antibiotics which included clindamycin, piperacillin/tazobactam, then cefepime and tobramycin at various points.A noncontrast computer tomography (CT) scan of the abdomen pelvis on admission was negative for any peri-nephric fluid collection. Overnight, he acutely decompensated and coded. Advanced cardiac life support protocol was initiated with return of spontaneous circulation after 20 minutes. Repeat CT angiogram (CTA) of the abdomen/pelvis was notable for a large retroperitoneal hematoma with active bleed from EPSA of the donor renal artery. Interventional radiology (IR) was consulted for placement of a covered stent. This intervention was unsuccessful, and ultimately, the patient was taken to the operating room and underwent transplant nephrectomy and saphenous vein patch angioplasty of the external iliac artery. The donor renal artery was completely avulsed from the recipient artery at the anastomosis site.The patient remained in the intensive care unit (ICU) postoperatively secondary to septic shock and multiorgan failure. On POD 39, he died of septic shock secondary to ischemic bowel and bowel perforation. Interestingly, the liver recipient from the same cadaveric donor, who was transplanted at another institution, also died suddenly at home.


### 2.2. Case 2 (Figure2)

Figure 2
Case 2 imaging, whose blood and urine cultures on admission grewEnterococcus faecalis. (a) Ultrasound from initial transplant hospitalization demonstrating normal RLQ transplant kidney with patent renal artery and vein without pseudoaneurysm. (b) Ultrasound on admission demonstrating pseudoaneurysm at the anastomosis measuring 5cm×4cm×6cm. (c) Noncontrast CT demonstrating 8cm×8cm hematoma in the same area of the pseudoaneurysm seen on ultrasound approximately 4 hours earlier. (d) Arteriogram demonstrating 5cm×5cm juxta-anastomotic pseudoaneurysm; it was deemed unsafe to coil given its wide neck. (e) Arteriogram on the following day after placement of a 16mm×14.5mm×10cm Gore excluder endograft. (f) CT angiogram demonstrating endograft placement completely excluding the anastomotic pseudoaneurysm.
(a)(b)(c)(d)(e)(f)The patient is a 63-year-old male with ESRD secondary to diabetes and hypertension who received a DDKT in January 2020. The patient’s immediate postop course was complicated by wound infection and dehiscence requiring multiple wash outs and biological mesh repair. Almost six months posttransplant, he was presented to a routine clinic follow-up with 1 week history of right flank pain, elevated blood pressure, hematuria, and a leaking sinus at his Gibson incision. Labs were significant for anemia and acute kidney injury with serum creatinine of 7 mg/dL from a baseline of 2 mg/dL.Ultrasound showed a juxta-anastomotic pseudoaneurysm measuring5×5 cm confirmed on CT with concern for a contained anastomotic leak. The patient was admitted to ICU and started on broad spectrum antimicrobials empirically, which included metronidazole, vancomycin, and micafungin. Blood and urine cultures from admission grew Enterococcus faecalis. Vascular surgery performed an angiogram that showed an anastomotic pseudoaneurysm, but it was deemed unsafe to coil due to a wide neck.After detailed discussion with the patient, we decided to proceed with a Gore excluder cover stent placement in the external iliac artery with loss of the transplanted kidney because of the expanding pseudoaneurysm. Surgical repair option was discussed but considered too high risk for this patient and still carried a significant chance of graft loss. After stent deployment, CTA confirmed an excluded pseudoaneurysm with no evidence of leak. Transthoracic and transesophageal echocardiograms showed no vegetation or evidence of endocarditis. Repeat blood and urine cultures on hospital days 3 and 5 were negative, and his antibiotic regimen was changed to ampicillin monotherapy. The patient was restarted on hemodialysis and discharged to an inpatient rehab facility to finish a six-week antibiotic course. The patient is still alive and awaits a second kidney transplant.


### 2.3. Case 3 (Figure3)

Figure 3
Case 3 imaging, whose urine cultures on admission grew vancomycin-resistantEnterococcus faecium. She had 4 UTIs since her transplant with unclear etiology; previous UTIs included VRE, Pseudomonas aeruginosa, and Candida tropicalis. (a) Ultrasound 1 month prior to admission demonstrating normal RLQ transplant kidney with patent renal artery and vein without pseudoaneurysm. (b) Ultrasound on admission demonstrating 3cm×3cm pseudoaneurysm arising from the renal transplant artery. (c) Arteriogram on the following day demonstrating a large and small pseudoaneurysm arising from the proximal and midtransplant artery, respectively. Severe stenosis also seen at the distal transplant artery. (d) Arteriogram demonstrating exclusion of both pseudoaneurysms as well as angioplasty of the distal transplant artery.
(a)(b)(c)(d)The patient is a 69-year-old female who received a DDKT in May 2021 and presented to clinic in July 2021 complaining of dysuria and pain at her Gibson incision. Her urine culture showed >100,000 CFU/mL vancomycin-resistantEnterococcus faecium (VRE). Labs were significant for a drop in hemoglobin to 8.7 g/dL from 11.2 g/dL. She had experienced four prior urinary tract infections (UTIs) since transplant with unclear etiology; previously urine cultures demonstrated Candida tropicalis, VRE, and Pseudomonas aeruginosa organisms, which were appropriately treated with active antimicrobials. Notably, she never had positive blood cultures at any point in her course. At this clinic visit, she was readmitted for treatment of the current VRE infection with daptomycin per infectious disease recommendations, given history of recurrent UTIs.CT abdomen/pelvis on admission demonstrated a subcutaneous hematoma measuring4×4×15 cm along her Gibson incision. Ultrasound of the transplanted kidney showed elevated peak velocities concerning for renal artery stenosis but gave no mention of pseudoaneurysm. A repeat transplant kidney ultrasound the next day showed a new onset 3×3 cm EPSA arising from the proximal transplant renal artery.Angiogram demonstrated a large and small EPSA arising from the proximal and midtransplant renal artery, respectively. There was no anastomotic EPSA. The distal transplant renal artery was severely stenosed but patent. Due to nonavailability of customized cover stent, the procedure was performed in two stages. Initially, the IR team coil embolized the larger EPSA, and she returned to IR the following day for placement of two6mm×20mm covered stents with angioplasty of the distal transplant renal artery. Repeat inpatient blood cultures were negative. She was discharged home on a four-week course of linezolid and fluconazole to cover the VRE and previous Candida tropicalis. The patient is doing well, and her repeat urine and blood cultures have remained negative of antimicrobials.


## 2.1. Case 1 (Figure1)

Figure 1
Case 1 imaging, whose blood and urine cultures on admission grewPseudomonas aeruginosa. (a) Ultrasound on admission demonstrating normal LLQ transplant kidney with patent renal artery and vein without pseudoaneurysm. (b) Noncontrast CT A/P demonstrating slight interval increase in size of hematoma compared to prior imaging. No evidence of active bleeding. (c) CT angiogram demonstrating irregular, actively bleeding pseudoaneurysm arising from the transplant renal artery ~1.2 cm from the anastomosis. (d) Arteriogram demonstrating pseudoaneurysm with active contrast extravasation. A 6mm×22mm covered stent was placed successfully within the proximal transplant renal artery; however, persistent hemorrhage warranted emergent surgical management.
(a)(b)(c)(d)The patient was a 68-year-old male with end stage renal disease (ESRD) secondary to Wegener’s granulomatosis who received his second deceased donor kidney transplant (DDKT) in November 2019. His postoperative course was significant for delayed graft function secondary to acute tubular necrosis (ATN). On postoperative day (POD) 19, he presented to clinic with complaints of fatigue, chills, and rigors. He was diagnosed with urosepsis. Both blood and urine cultures on admission grewPseudomonas aeruginosa. Patient was started on broad spectrum antibiotics which included clindamycin, piperacillin/tazobactam, then cefepime and tobramycin at various points.A noncontrast computer tomography (CT) scan of the abdomen pelvis on admission was negative for any peri-nephric fluid collection. Overnight, he acutely decompensated and coded. Advanced cardiac life support protocol was initiated with return of spontaneous circulation after 20 minutes. Repeat CT angiogram (CTA) of the abdomen/pelvis was notable for a large retroperitoneal hematoma with active bleed from EPSA of the donor renal artery. Interventional radiology (IR) was consulted for placement of a covered stent. This intervention was unsuccessful, and ultimately, the patient was taken to the operating room and underwent transplant nephrectomy and saphenous vein patch angioplasty of the external iliac artery. The donor renal artery was completely avulsed from the recipient artery at the anastomosis site.The patient remained in the intensive care unit (ICU) postoperatively secondary to septic shock and multiorgan failure. On POD 39, he died of septic shock secondary to ischemic bowel and bowel perforation. Interestingly, the liver recipient from the same cadaveric donor, who was transplanted at another institution, also died suddenly at home.


## 2.2. Case 2 (Figure2)

Figure 2
Case 2 imaging, whose blood and urine cultures on admission grewEnterococcus faecalis. (a) Ultrasound from initial transplant hospitalization demonstrating normal RLQ transplant kidney with patent renal artery and vein without pseudoaneurysm. (b) Ultrasound on admission demonstrating pseudoaneurysm at the anastomosis measuring 5cm×4cm×6cm. (c) Noncontrast CT demonstrating 8cm×8cm hematoma in the same area of the pseudoaneurysm seen on ultrasound approximately 4 hours earlier. (d) Arteriogram demonstrating 5cm×5cm juxta-anastomotic pseudoaneurysm; it was deemed unsafe to coil given its wide neck. (e) Arteriogram on the following day after placement of a 16mm×14.5mm×10cm Gore excluder endograft. (f) CT angiogram demonstrating endograft placement completely excluding the anastomotic pseudoaneurysm.
(a)(b)(c)(d)(e)(f)The patient is a 63-year-old male with ESRD secondary to diabetes and hypertension who received a DDKT in January 2020. The patient’s immediate postop course was complicated by wound infection and dehiscence requiring multiple wash outs and biological mesh repair. Almost six months posttransplant, he was presented to a routine clinic follow-up with 1 week history of right flank pain, elevated blood pressure, hematuria, and a leaking sinus at his Gibson incision. Labs were significant for anemia and acute kidney injury with serum creatinine of 7 mg/dL from a baseline of 2 mg/dL.Ultrasound showed a juxta-anastomotic pseudoaneurysm measuring5×5 cm confirmed on CT with concern for a contained anastomotic leak. The patient was admitted to ICU and started on broad spectrum antimicrobials empirically, which included metronidazole, vancomycin, and micafungin. Blood and urine cultures from admission grew Enterococcus faecalis. Vascular surgery performed an angiogram that showed an anastomotic pseudoaneurysm, but it was deemed unsafe to coil due to a wide neck.After detailed discussion with the patient, we decided to proceed with a Gore excluder cover stent placement in the external iliac artery with loss of the transplanted kidney because of the expanding pseudoaneurysm. Surgical repair option was discussed but considered too high risk for this patient and still carried a significant chance of graft loss. After stent deployment, CTA confirmed an excluded pseudoaneurysm with no evidence of leak. Transthoracic and transesophageal echocardiograms showed no vegetation or evidence of endocarditis. Repeat blood and urine cultures on hospital days 3 and 5 were negative, and his antibiotic regimen was changed to ampicillin monotherapy. The patient was restarted on hemodialysis and discharged to an inpatient rehab facility to finish a six-week antibiotic course. The patient is still alive and awaits a second kidney transplant.


## 2.3. Case 3 (Figure3)

Figure 3
Case 3 imaging, whose urine cultures on admission grew vancomycin-resistantEnterococcus faecium. She had 4 UTIs since her transplant with unclear etiology; previous UTIs included VRE, Pseudomonas aeruginosa, and Candida tropicalis. (a) Ultrasound 1 month prior to admission demonstrating normal RLQ transplant kidney with patent renal artery and vein without pseudoaneurysm. (b) Ultrasound on admission demonstrating 3cm×3cm pseudoaneurysm arising from the renal transplant artery. (c) Arteriogram on the following day demonstrating a large and small pseudoaneurysm arising from the proximal and midtransplant artery, respectively. Severe stenosis also seen at the distal transplant artery. (d) Arteriogram demonstrating exclusion of both pseudoaneurysms as well as angioplasty of the distal transplant artery.
(a)(b)(c)(d)The patient is a 69-year-old female who received a DDKT in May 2021 and presented to clinic in July 2021 complaining of dysuria and pain at her Gibson incision. Her urine culture showed >100,000 CFU/mL vancomycin-resistantEnterococcus faecium (VRE). Labs were significant for a drop in hemoglobin to 8.7 g/dL from 11.2 g/dL. She had experienced four prior urinary tract infections (UTIs) since transplant with unclear etiology; previously urine cultures demonstrated Candida tropicalis, VRE, and Pseudomonas aeruginosa organisms, which were appropriately treated with active antimicrobials. Notably, she never had positive blood cultures at any point in her course. At this clinic visit, she was readmitted for treatment of the current VRE infection with daptomycin per infectious disease recommendations, given history of recurrent UTIs.CT abdomen/pelvis on admission demonstrated a subcutaneous hematoma measuring4×4×15 cm along her Gibson incision. Ultrasound of the transplanted kidney showed elevated peak velocities concerning for renal artery stenosis but gave no mention of pseudoaneurysm. A repeat transplant kidney ultrasound the next day showed a new onset 3×3 cm EPSA arising from the proximal transplant renal artery.Angiogram demonstrated a large and small EPSA arising from the proximal and midtransplant renal artery, respectively. There was no anastomotic EPSA. The distal transplant renal artery was severely stenosed but patent. Due to nonavailability of customized cover stent, the procedure was performed in two stages. Initially, the IR team coil embolized the larger EPSA, and she returned to IR the following day for placement of two6mm×20mm covered stents with angioplasty of the distal transplant renal artery. Repeat inpatient blood cultures were negative. She was discharged home on a four-week course of linezolid and fluconazole to cover the VRE and previous Candida tropicalis. The patient is doing well, and her repeat urine and blood cultures have remained negative of antimicrobials.


## 3. Discussion

EPSA is a rare (1% incidence rate) but devastating complication of kidney transplantation. EPSA can occur at or adjacent to the surgical anastomosis, usually secondary to a mycotic or bacterial infection. Previous literature reviews place the incidence of allograft loss at 56%, concurrence with an infective pathogen at 62%, and mortality at 14% [8]. In multiple retrospective series, C. albicans was the leading pathogen in cases with infection [8–10]. The mechanism by which mycotic and bacterial pseudoaneurysms develop is well-described in the literature, involving an inflammatory process that invades and compromises the wall of the artery [11].Patients with kidney transplants often have multiple risk factors for opportunistic infections, including immunosuppression, end-stage renal failure, diabetes mellitus, hypertension, and dyslipidemia [12–14]. Additionally, prolonged ICU stays (>7 days) and extended operative times are associated with increased incidence [15]. Intuitively, age should be a risk factor for all operative complications, but this association is not reflected in the data [16]. Procurement of organs, transportation, back-table preparation, and transplantation involve countless opportunities for inadvertent contamination; the likelihood of transplant contamination is estimated at 40% [12]. This prevalence highlights the importance of obtaining donor cultures from multiple sites, careful handling of the allograft, and strict sterile technique at all times. Organ procurement organizations (OPO) work extensively with the donor centers to ensure minimal infection risk, frequently involving infectious disease colleagues to confirm thorough treatment and prophylaxis. While we extensively scan donors, preservation fluid, and recipient blood cultures, some smoldering infections can be masked or subdued by extended courses of antibiotics, making detection of some pathogens difficult [14].The clinical presentation of EPSAs varies considerably, evident both within our own cases and the literature. Patients can be totally asymptomatic (Case 3) or acutely decompensating from aneurysmal rupture (Case 1). Time to diagnosis varied both within our own case series as well as cases in literature, ranging from a few days to many years after the initial transplant. Other symptoms include pulsatile masses, abdominal tenderness, lower limb ischemia, allograft dysfunction, anemia, or signs of infection [4, 15, 17]. Doppler ultrasonography is the first imaging tool used, ideally showing the pathognomonic “Yin Yang” sign indicating turbulent mixing of blood as exhibited in Figures 2(b) and 3(b). CT or magnetic resonance (MR) angiography can confirm the pathology as well as evaluate its impact on surrounding structures such as the ureter or iliac vessels [18]. Conventional angiography elucidates the exact location and occasionally allows for simultaneous percutaneous treatment.All three of our cases presented with an associated infection. In Case 1,Pseudomonas aeruginosa grew in urine and blood cultures; per literature review, this is the most frequent bacteria associated with EPSA occurrence [8, 11]. Rapidly developing an EPSA in less than 3 weeks, Case 1 is a good reminder that all infections, especially pathogens historically linked to the formation of EPSAs such as Pseudomonas, should trigger aggressive, immediate treatment, and surveillance after antibiotic completion. Case 2 is notable as Enterococcus faecalis has only been associated with EPSA in one other case in the literature. Notably, Case 3 had multiple UTIs prior to discovering the EPSA, but no positive blood cultures. In this instance, it is possible that long-term treatment for her multiple UTIs masked a developing vascular insult, at which point the EPSA was incidentally noted.Indications for repair of an EPSA are controversial, but pseudoaneurysms with a diameter of >2.5 cm are almost uniformly at a high risk of rupture [1, 7, 15, 16, 19]. Additional intervention indications include symptom severity, rate of size enlargement, presence of infection, and renal artery hypertension [1, 15]. EPSAs smaller than 2 cm can usually be managed conservatively with serial imaging and resolve spontaneously in some cases [20]. Therapeutic options for large or high-risk EPSAs include allograft nephrectomy, conventional open repair (allograft removal, creation of new vascular anastomoses, and repair of previous site with patch angioplasty), endovascular stenting or coiling, and/or ultrasound-guided percutaneous thrombin injection [14, 21]. In both our own practice and literature review, transplant nephrectomy represented the gold standard for definitive treatment but is a tough decision. Endovascular intervention represents a promising future for repair that retains allograft function, but, as in Case 2, sometimes necessitates excluding the allograft to prevent rupture. In such scenarios, a transplant nephrectomy may be performed later based on the patient’s clinical condition (development of allograft abscess, etc.). The authors, including Lin et al. and Cano-Velasco et al., have compiled past articles on this subject, and Cano-Velasco et al. proposed a treatment algorithm based on these reports [8, 16].Management of EPSA requires a multidisciplinary approach. Patient and allograft salvage are the prime goal. Newer endovascular techniques open new options for salvaging the graft. Each case is different and needs thorough assessment and unique plan development based on the patient’s needs.


## 4. Conclusion

EPSA of the transplant renal artery is a rare issue. Prevention, high degree of suspicion, and aggressive multidisciplinary management are needed to save the patient and renal allograft. Surveillance of patients with previous urinary or bloodstream infections is also recommended.



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