PCNL is the treatment of choice for patients suffering from large and complex kidney stones. This method which has several advantages over open stone surgery, was introduced in the 1980s and its development in the following years led to higher efficacy and lower morbidity (1). Although the nephrostomy tube (NT) is placed after the PCNL procedure by most institutes, the tubeless method has also been studied (2).
While PCNL is usually efficient in large kidney stone removal, one of this technique's significant limitations is the need for a second procedure due to residual fragments. Flexible nephroscopy may eliminate the possibility of residual stones. There are different options to remove these fragments, including shockwave lithotripsy (3), retrograde internal surgery (4), and second-look PCNL (5). Whether a patient needs a secondary procedure is based on the findings during the surgery or the information collected from the postoperative images. CT scan is the most sensitive diagnostic method for detecting stone residue (6).
According to the images, we performed the second-look nephroscopy to see if the residual stone was found in the kidney. In this procedure, we pass the collecting system percutaneously through the tract, established during the PCNL procedure, to remove the remaining stones. This process is performed before patient discharge or as an outpatient if the nephrostomy has not yet been removed. The procedure can be performed with local, general, or spinal anesthesia (7). Some researchers recommend second-look nephroscopy for all patients after PCNL, stating that about 17% of these patients have residual fragments after PCNL (8). Still, the general recommendation is to perform the procedure for those patients who have undergone post-surgical evaluation with positive results (9).
As hematuria impaired visibility, it is best to postpone the second-look procedure until complete recovery of hematuria. After a thorough evaluation before surgery, the patient will be in the prone position, and we begin the procedure by cutting the nephrostomy tube about 3-4 cm from the skin level. The nephrostomy tube is completely prepped. After this, a 0.035 dual Duranter guide wire (Sensor, Boston, Natick, MA) is inserted through the nephrostomy tract and coiled in the collection system. Following this step, the nephrostomy tube is removed. The dilator and amPlatz are passed through the guidewire simultaneously (10).
In our department, PCNL is usually performed as tubeless. Still, when there is a need for a second-look procedure (due to the high volume of stone, excessive surgical time, impaired vision due to systemic hematuria, and patient conditions), we insert an open-ended 16 Fr Foley catheter as nephrostomy. A second look procedure is inevitable if the post-surgical CT scan indicates a significant volume of stone residues. Thus, after hematuria recovery and improvement of the patient's general condition in the same time interval, we perform the second look nephroscopy.
The patient agreed to report his case by signing the informed consent, and the case report is based on CARE guidelines. In this case, the surgery was performed on a 45-year-old man with full staghorn calculi. After about 3 hours of surgery because of tachycardia and a fall in the patient's blood pressure. Because of the impaired vision due to severe hematuria, the possibility of remaining fragments was high. So, Foley 16 f was inserted, but we mistakenly forgot to open one end of it. A significant volume of stone residue was observed in the post-op CT scan two days after the surgery. Four days after surgery, the patient was transferred to the operating room after improving the clinical status and hematuria removal. The procedure was done in a prone position and under general anesthesia. After cutting the nephrostomy tube, the attempt to insert the wire was not successful. So, we removed the nephrostomy tube. After retrograde injection of the contrast agent and fluoroscopy, we observed the contrasting agent passage through the nephrostomy tract to the skin surface. With the help of ureteroscopy, direct vision (Figure 1), and fluoroscopy (Figure 2), we found the last tract, entered the pyelocaliseal system, and embedded the guidewire. Thus, we performed nephroscopy from the previously established tract without needing re-access.
Figure 1. FUreteroscopy of the tract
Figure 2. a, b, c: Fluoroscopy steps for tract examination with ureteroscopy
The patient was stone-free after the second procedure. The first procedure time was 3 hours, and the second procedure time was 50 minutes. The mean hemoglobin level at first admission was 14.5, which fell to 8.7 at the end of the procedure, and the patient revived transfusion. On the second loop surgery, the hemoglobin level was 10.3 and was stable at the end of the procedure.
While PCNL has a high success rate in large stone removal, usually residual stones are left at the site, which requires a secondary removal procedure. While some scholars state that routine second-look nephroscopy is not necessary, maybe due to routine flexible nephroscopy, it is the most attractive option in some centers, like our center, due to the limitation of flexible nephroscopy, to remove residual fragments (11). The primary reason for this statement is the ease of access to the collecting system due to the pre-established tract (5, 12-15). According to the data collected by Shahrour et al., while only 51% of the patients undergoing PCNL were stone-free, after the second-look procedure, this number increased to 76% (14). In another study conducted on children, performing a second-look procedure after the initial PCNL resulted in an 87% stone-free rate (12). Although there was a considerable effort to reduce the number of second-look nephroscopy, it is impossible to eliminate it because of the remaining possibility of residual fragments in cases of severe hematuria or retained contrast (7).
Accurate determination of significant residual stone fragments after PCNL has some challenges. Fluoroscopy and direct visualization are aids that help the surgeon detect the complete removal of stone during the surgery. In this case study, we showed that simultaneous fluoroscopy and endoscopy is an excellent ways to find the previously established tract in cases where second look nephroscopy is required or tubeless PCNL was performed. This phenomenon is valid as long as the second procedure is performed not long after the initial PCNL.
All authors had an equal contribution.
Special thanks to the Urology Research Center (URC), Tehran University of Medical Sciences (TUMS).
Conflict of interest
The authors declare that there are no conflicts of interest regarding the publication of this manuscript.
There is no funding.
The patient agreed to report his case by signing the informed consent, and the case report is based on CARE guidelines.
Data will be provided by the corresponding author on request.
CT Computerized tomography
PCNL Percutaneous nephrolithotomy