Gangrene of the Kidney Following Percutaneous Renal Cryoablation of a Small Tumor

Abstract

Background: In selected cases cryoablation is a valid treatment option for small renal masses. The procedure is generally considered oncologically efficient with a low rate of severe complications. We report here a case of a 62-year-old man who after percutaneous cryoablation develops severe gangrene in the treated kidney.

Case Presentation: A 62-year-old man was incidentally diagnosed with a 45-mm renal cell carcinoma. The tumor was found on a CT scan performed on the suspicion of diverticulitis. An abscess in relation to the sigmoid was found and he was treated with aspiration and antibiotics. The tumor was treated with percutaneous cryoablation 20 days later. On the third postoperative day, he was readmitted with urosepsis. A CT scan revealed gangrene at the ablation site, and a nephrectomy was performed. Clinical progress was slow, and a new CT scan showed reformation of the abscess at the sigmoid and a suspicion of a colonic tumor was raised. This was confirmed by coloscopy and biopsy. The patient had a right hemicolectomy, and the pathology report described a T4 adenocarcinoma with positive margins. After 4 months follow-up, metastases to the lungs was found and the patient was referred to further oncologic treatment.

Conclusion: Renal cryoablation is generally a very safe procedure, but severe complications may occur. This case report highlights that attention should be given to recent abdominal infections and that delayed intervention might be in place in selected cases.

Introduction

Percutaneous renal cryoablation is generally considered an efficient treatment of small renal tumors and serious complications related to the treatment are uncommon.¹

At Aarhus University Hospital, renal cryoablation has been performed since 2005, initially as a laparoscopic procedure, but since 2014, a CT-guided percutaneous approach has been applied.

In this study we report a rare, but serious, case of gangrene of the kidney after percutaneous cryoablation.

Case Report

A 62-year-old man was admitted to a regional hospital with abdominal pain and diagnosed with perforated diverticulitis at the proximal sigmoideum. The patient had slightly impaired kidney function, but no other comorbidities. As part of the work-up, a CT scan revealed a 40-mm tumor at the upper pole of the left kidney. The patient was treated with aspiration of the abscess and intravenous antibiotics with metronidazole and piperacillin with tazobactam. From the aspirate of the abscess, a range of bacteria were cultured, including Escherichia coli and Klebsiella pneumoniae. The patient responded well to the antibiotics, and was treated a total of 10 days.

FIG. 1.

(A) CT image of the tumor at the upper pole of the left kidney pre ablation. (B) CT image of the gangrene at the ablation site on the day of readmission.

A biopsy of the tumor confirmed that it was a renal clear cell carcinoma. The renal tumor was found suitable for percutaneous cryoablation and the procedure was performed 20 days after the antibiotic treatment was completed. No antibiotics was given peroperatively and the patient was discharged the following day, with no immediate complications.

On the third postoperative day, the patient was readmitted at the primary hospital with sepsis and pain around his left hip. He was treated initially with piperacillin and tazobactam, intravenous fluids, and morphine. Blood works showed increased creatinin (158 μmol/L compared with 98 μmol/L preablation), C reactive protein 307 mg/L, and leukocytes 17,6 10⁹/L. The initial suspicion was urosepsis. K. pneumoniae (sensitive to the chosen antibiotic) was cultivated from both blood and urine.

On the fifth postoperative day, a CT scan showed air formation at the ablation site and signs of infection, but no abscess. Initial urologic assessment recommended a conservative approach with antibiotics, and the next day the patient was referred to the urologic department. At arrival, the patient was awake and relevant with stable vital parameters, but biochemically, there was no response to the treatment. The patient became increasingly somnolent, and had trouble maintaining blood pressure and oxygen saturation. On the seventh day, a laparoscopic nephrectomy was performed. During the procedure, there was a need for massive inotropic support, and the patient was afterward admitted and intubated to the intensive care unit. On the ninth day after ablation, the infection markers were decreasing and the inotropic support could be abandoned. Owing to slow clinical progress, a new CT scan was performed that revealed an abscess at the site of the initial intestinal perforation and a suspicion of a tumor in the colon was raised. A colonoscopy with biopsy confirmed the suspicion.

On the 35th day after the ablation, the intestinal tumor was resected with an open left colectomy. The histology report showed a T4N1 adenocarcinoma of the colon with positive margins. The clinical state of the patient improved after the operation, and he was discharged 16 days later. Follow-up after 4 months raised suspicion of metastases to the lungs, which was confirmed by biopsy, and the patient was referred to the oncologic department for further treatment.

The histology report of the removed kidney showed an abscess, hemorrhagic infarction, and no vital tumor cells.

Discussion

We report here a serious life-threatening complication after renal cryoablation. Cryoablation is generally considered safe and a recent analysis from the European Registry for Renal Ablation (EuRECA) found the overall complication rate to be 8.3%. However, severe complications (Clavien–Dindo 3–5) were only found in 3.4% of cases.¹

At our institution, cryoablation is generally recommended to patients with tumors <40 mm and no contraindications. We have performed cryoablation since 2005, and recently long-term survival data have been published.²

Crawford et al. reviewed the literature regarding infections and the use of prophylactic antibiotics for various renal ablation techniques. They described fever in only 1.06% of the treated patients, and the use of prophylactic antibiotics was only mentioned in 0.06% of the cases.³

In the present case, the patient had been treated for an abscess related to a perforated diverticulitis, but had been clinically well and without antibiotic treatment for 20 days before the cryoablation. Nevertheless, the same bacteria (K. pneumoniae) were found in the aspirate of the primary abscess and in the blood and urine at his emergency admission. K. pneumoniae is common gut bacteria and a well-described causative agent of nonclostridial gas gangrene.⁴

From the study of Nielsen et al., we know that the cryolesion site is highly hyperemic shortly after treatment.⁵ The coagulative necrosis found in a recent cryolesion could potentially have served as a medium for hematogenic seeding of bacteria from the perforation of the sigmoid.

In this case, we chose to perform a nephrectomy, as the patient developed septic shock despite proper antibiotic treatment. An early insertion of a percutaneous drain may have limited the development of the infection, but the CT scan did not show a drainable abscess.

Retrospectively, this patient should not have been treated for his renal tumor. The tumor was relatively small, and the patient turned out to have a T4N1 adenocarcinoma in the colon. Since this case, we have adjusted our clinical practice and recent abdominal infections result in delayed intervention, with ablation being delayed 3 months.

Conclusion

Renal cryoablation is generally a safe procedure, but severe complications can arise. This case of gangrene in the ablation site has not previously been described in the literature, and knowledge of this potential severe complication may shorten the diagnostic delay and time to proper surgical treatment. Furthermore, we advocate for delayed cryoablative intervention (e.g., 3 months) after a severe abdominal infection.

Abbreviation Used

CT

computed tomography

Disclosure Statement

No competing financial interests exist.

Funding Information

No funding was received.

Cite this article as: Vedel PF, Borgbjerg J, Nielsen TK (2020) Gangrene of the kidney following percutaneous renal cryoablation of a small tumor, Journal of Endourology Case Reports 6:4, 490–492, DOI: 10.1089/cren.2020.0139.