Kidney stones are diagnosed in about 4% of the general population worldwide, and the incidence seems to be slowly increasing in the past decades.¹The actual cause behind kidney stones remains unknown and prophylactic measures only display limited results. Furthermore, no new drugs have become available forthe prevention of kidney stones since the 1980s when potassium citrate was introduced.²Therefore, finding an effective treatment that would at the same time be minimally or non-invasive has remained a constant challenge for urologists during the modern age of medicine. The development of endoscopic techniques marked a great step forward in the treatment of many conditions, including urinary lithiasis.

Percutaneous NephroLithotomy (PCNL) is one modern alternative in renal stone management, a technique widely used in most urological centers, being a rapid way to achieve the stone free apotheosis. Despite its advantages related to stone removal, such as being fast and minimally invasive, this technique also associates a lot of intraoperative and postoperative complications, some of them posing a serious risk to the patient’s health. Although data from the literature supports PCNL as being a safe and effective technique, the urologist needs to be aware of all potential complications to be able to find fast and reliable measures to deal with any unforeseen unfavorable evolution of the patient.

One of the most serious postoperative complications of PCNL is uncontrolled bleeding from the kidney, which may occur into the collecting system, outside the kidney or both. This can lead to a fast deterioration of the general status of the patient, and requires immediate action with the aim of saving the patient’s life. One classic alternative in this scenario is a nephrectomy, which solves the case, but bears the very high cost of losing a kidney, with lifelong implications for the patient. At the same time, this alternative might have serious legal implications for the surgical team.

A more conservative approach uses interventional arteriography for the embolization of the bleeding vessel, a modern technique which is able to stop the bleeding while saving the kidney. However, this treatment requires highly trained medical personnel, sophisticated equipment and expensive materials, so this might not always be available. Even when all the conditions are met, a successful embolization might still be challenging for the medical team involved in this procedure.

Case report

We present the case of a 51-year old woman who presented in our department for recurrent pain in the left lumbar area, which had started about 2 months before. Under non-steroidal anti-inflammatory (NSAID) treatment, the pain diminished until disappearance onlyto reappear shortly after.

The relevant medical history included autoimmune thyroiditis and hepatic steatosis, which had been diagnosed 2 years prior to presentation and for which the patient was under treatment with levothyroxine 100 pg OD and milk thistle 150 mg OD.

After the clinical exam, the patient performed ultrasound and intravenous urography exploration revealed a 17 mm stone in the left renal pelvis (Figure 1-A,B,C).

 

 Figure 1A. Abdominal radiography revealing a radio-opaque stone in the left kidney area

 

 Figure 1B. Abdominal radiography at 5 minutes after intravenous contrast-substance was administrated

 

 

 Figure 1C. Abdominal radiography at 45 minutes after intravenous contrast-substance was administrated revealing a delay of the urine drainage on the left urinary system

 

 

 

We discussed the treatment alternatives with the patient and offered PCNL or 2 to 3 sessions of Extracorporeal Shock Wave Lithotripsy (ESWL). The patient chose to undergo PCNL because this was the fastest way to treat the stone, with better success rates than ESWL.

Prior to the procedure all blood tests were in the normal range. A left PCNL was performed and after the intervention, a stone-free status was obtained and an internal drainage by double J catheter was left in place. The postoperative evolution was good and the patient was discharged in the 4^th day following the intervention.

In about 7 days after being discharged, the patient was hospitalized with gross hematuria, describing the first episode about 10 hours before. The patient reported that a day before this episode she had removed the double J catheter herself, because the vesical tip of the catheter had spontaneously protruded out through her urethra, so she pulled it out.

A urethrovesical catheter was placed and blood tests were performed, all showing normal values. Approximately 2 hours after hospitalization the hematuria stopped.

In the 14^th day after the intervention, while still being hospitalized, the hematuria restarted, this time as severe bleeding so that after 30 minutes the systolic blood pressure had dropped to 75 mmHg and blood tests revealed a hemoglobin level of 7 g/dL. The blood loss was compensated with 500 mL of blood of the same group and the interventional radiology department was contacted to try an embolization of the affected blood vessel. Before the arteriography, the systolic blood pressure was around 105 mmHg.

The patient was transferred to the interventional radiology department and a left kidney arteriography via left brachial artery was promptly performed. After the injection of contrast medium in the left renal artery, there was no evidence of active bleeding (Figure 2). The radiologist decided to inject heparin intra-arterially, but on the left renal arteriography there was still no evidence of any ruptured blood vessel.

After another intraarterial administration of heparin with high pressure, the arteriography revealed an extravasation of the contrast substance through an inferior branch of the left renal artery (Figure 3). After the catheterization of this affected branch, 2 coils were placed (Figure 4) and the embolization ended with a complete stop of the bleeding, with no extravasation at the control arteriography (Figure 5).

Figure 3. Left kidney arteriography revealing an active bleeding after high pressure heparine administration

Figure 4. Left kidney radiography revealing the coils placed in the affected arterial branch

Figure 5. Left kidney arteriography revealing no bleeding after the selective embolization

The following day after the embolization, blood tests revealed a hemoglobin level of 7,5 g/dL, but the urine was still dark red, with small clots, which we interpreted as lysis of the clots from the upper urinary system.

In the 7^th day following the embolization the patient was discharged with 10g/dL of hemoglobin and almost clear urine.

PCNL is a technique widely used in treating kidney stone disease but although it has major benefits, allowing large stones to be treated in a minimally invasive fashion, the complications that may accompany this procedure must also be considered, including excessive hemorrhage,  adjacent organ injury, or infection. 3,4 Perioperative hemorrhage is a major complication that appears mostly due to arteriovenous fistulas and in about 8-10% of cases blood transfusions are needed. 5,6 The kidney is a highly vascularized organ and during PCNL the risk of injuring a blood vessel is high, occurring in about 3-23% of cases. 7 Venous bleeding is usually self-limited or well controlled with nephrostomy tubes, but arterial vessel injuries can lead to serious bleeding that may require selective angiographic embolization or nephrectomy. Angiographic embolization is a minimally invasive modern procedure for the management of post PCNL bleeding with excellent results when performed in specialized dedicated centers and in about 97 % of cases the bleeding is controlled.8 However, this technique requires very well trained personnel and can only be done in emergency medical centers, well-equipped and available 24 hours a day. Our case has the particularity of a late onset bleeding, several days after the patient was discharged. Before the bleeding started, no sign or symptom suggested anything abnormal, so there is probably nothing that could have been done to prevent the future escalation of the situation. The second particular aspect was the difficulty in identifying the ruptured vessel, which was not bleeding by the time the radiologist tried the embolization. Even after a first provocative maneuver the bleeding was still impossible to diagnose, so if the procedure had been stopped at that point, the cause of bleeding would have persisted. Such cases are not common in our daily practice but they always represent reference points for our experience, despite of the fact that there generally is nothing we can do to prevent them from happening.

PCNL remains the gold standard for treating kidney stones which are not suitable for ESWL, but this minimally invasive procedure poses a significant risk, which cannot be assessed at any time before or during the intervention. A comprehensive discussion with the patient before surgery is mandatory and all potential complications and outcomes, regardless their incidence in real life, must be explained. The selling points when proposing PCNL to a patient are its minimal invasivity, the fast healing and the relatively high stone-free rates of the technique. But the patient also needs to be aware of all potentially unfavorable outcomes or complications occurring after the procedure, so a fully informed consent to be obtained.

1.Romero V, Akpinar H, Assimos DG. Kidney stones: a global picture of prevalence, incidence, and associated risk factors. Rev Urol 2010;12:e86-96.

2.Morgan MSC, Pearle MS. Medical management of renal stones. BMJ 2016;352:i52. [Crossref]

3.Knoll T, Daels F, Desai J, et al. Percutaneous nephrolithotomy: technique. World J Urol 2017 [Crossref]

4.Sharma K, Sankhwar S, Goel A, Singh V, Sharma P, Garg Y. Factors predicting infectious complications following percutaneous nephrolithotomy. Urol Ann 2016;8:434. [Crossref]

5.Un S, Cakir V, Kara C, et al. Risk factors for hemorrhage requiring embolization after percutaneous nephrolithotomy. Can Urol Assoc J 2015;9:594-8. [Crossref]

6.Nasirov FR, Mirkhamidov DK, Giyasov SI, et al. Evaluation of the efficacy of standard percutaneous nephrolithotripsy in staghorn and multiple nephrolithiasis. Urologiia 2015;1:66–9.

7.Jinga V, Dorobat B, Youssef S, et al. Transarterial embolization of renal vascular lesions after percutaneous nephrolithotomy. Chirurgia (Bucur) 2013;108:521–9.

8.Ren YM, Wu XM, Wen Y, et al. Recurrent bleeding following the renal artery embolization treating post-percutaneous nephrolithotomy hemorrhage: causes and countermeasure. Zhonghua Yi Xue Za Zhi 2017;97:22–5. [Crossref]