Pyelolithotomy Treatment & Management

Prior to surgery, if the nature of the infecting organism is known, use the appropriate intravenous antibiotic based on culture results. If culture results are not available, use a broad-spectrum antibiotic. Assume all candidates for open pyelolithotomy are or will be infected at the time of surgery because renal pelvic stones tend to harbor bacteria.

The goal of the preoperative evaluation includes improving the patient's general condition as much as possible, especially if sepsis is present. In a septic patient, drain the kidney using a stent or via nephrostomy. Let the kidney rest for 48-72 hours, if possible, so that the inflammation from the infection subsides. A less inflamed kidney is less friable and bleeds less.

A stent is not required but may aid in ureteral identification if in place. In addition, a stent prevents stone fragments or debris from blocking the ureter. Even though the renal pedicle is generally anterior to the renal pelvis, at times a posterior branching blood vessel may be present. Approaching the renal pelvis posteriorly is easier. Infected urine can be drained posteriorly using a retroperitoneal drain.

The left-sided testicular or ovarian vein may resemble the ureter. When in doubt, feel for the stent or aspirate with a 22-gauge needle and syringe.

Properly positioning the patient is key for easier surgery. Be prepared to perform an extended pyelotomy. Always dissect the upper and lower poles of the kidney and renal pedicle or, at least, be prepared to do so.

A pyelolithotomy can be performed as an open, laparoscopic, ^[4]  or robotic ^{[5, 6]}  procedure. The approach can be transperitoneal or retroperitoneal. 

Use endotracheal general anesthesia. Insert a Foley catheter. Consider placing a ureteral stent to aid in identification of the ureter.

During renal pelvis dissection, it is important to adequately expose the renal pelvis and identify all surrounding vascular branches and the ureteropelvic junction (UPJ).

A vertical incision should be made. Consider placing stay stitches at the apex of the pyelotomy to avoid extension into the infundibula. Extension into the calyces can occasionally be required. Graspers should be used to grasp the stone and extract it intact if possible. Stones should be counted as they are removed to ensure that all stones noted on preoperative imaging were removed. Irrigate the pyelotomy with normal saline to eliminate stone debris. Thorough inspection for residual stones can be performed by inserting a flexible cystoscope or ureteroscope and directly visualizing all calyces. An endoscopic basket can be used to grasp residual stone fragments. The pyelotomy can then be closed using an absorbable suture. Urinary drainage with a ureteral stent and/or nephrostomy tube is required. An extrarenal drain can be placed to detect a urine leak. Copiously irrigate the surrounding tissue to reduce the risk of abscess. 

Coagulum pyelolithotomy

Coagulum pyelolithotomy is used when multiple small stones are present and are scattered throughout the calyceal system. Coagulum, or a clot, envelops the small stones, and fragments are removed with it.

Into the renal pelvis through a 19-gauge needle, inject cryoprecipitate and 1 mL of methylene blue and inject 1 mL of thrombin and calcium chloride. Do not overdistend the renal pelvis.

Block the ureter with a noncrushing bulldog clamp. Thrombin and calcium chloride solution can be made by adding 5000 U of thrombin to 5 mL of saline and adding 10 mL of 10% calcium chloride. Another method to make coagulum is to inject the necessary volume of cryoprecipitate (ie, volume equal to that of the renal pelvis) and inject 1 mL of 10% calcium chloride. After 5-7 minutes, the clot is formed. The thromboplastin from the renal pelvis is used. Pyelolithotomy is then performed, and the clot, along with the stones, is removed.

The procedure is usually safe, but pulmonary embolism and hepatitis are possibilities. This procedure is rarely performed in the United States because of concerns about possible infectious agents in the materials used.

Summary

Note the following key points:

• The kidney is always higher than estimated.

• Position is the key for easier surgery.

• Incise skin and muscles toward the xiphisternum.

• Identify the ureter.

• Mobilize the whole kidney (all around).

• Be prepared to extend the incision in the renal pelvis to the calyx (Gil-Vernet procedure).

• Extend the incision across the UPJ if needed to remove a larger stone, but close it transversely to prevent narrowing.

A plain x-ray film of the abdomen (KUB) is essential because kidney stones are notorious for moving. Kidney position is always higher than visualized on the x-ray film; always incise above the site noted. Always assume more than one stone is present in the renal pelvis. Make a bigger incision to gain better exposure. Be prepared to take intraoperative x-ray films.

Recognize the left testicular vein or ovarian vein on the left side and on the right side of the vena cava. Gonadal veins may be sacrificed if the need arises. Always mobilize the entire kidney, both upper and lower poles. Be prepared to extend the pyelotomy incision. The UPJ is not inviable; make sure it is not narrowed when closing.

If necessary, perform an extended pyelolithotomy to remove a larger stone. Always use stone forceps to remove the stones, not regular forceps. When in doubt, perform a nephroscopy or obtain an intraoperative x-ray film. When a caliceal stone is present, incise the calyx and the infundibulum and then remove the stone with the stone forceps. If several small stones are present, consider the use of a coagulum pyelolithotomy.

Pain is less severe if bupivacaine (Marcaine) is injected, but be absolutely sure that the bupivacaine is not accidentally injected into a vessel because it can cause cardiac arrhythmias.

Drains may be removed in 24 hours if the drainage is less than 25 mL. Ureteral stents can be removed after 2 weeks. If a ureteral catheter is used as a stent, it can be removed after 5 days.

Perform an imaging study to confirm the removal of all stone particles.

As with all renal stone procedures, a urinary tract infection or pyelonephritis may occur. Perinephric abscesses may require percutaneous drainage. Retained stone fragments, ureteral/renal pelvic scarring, and obstruction are possibilities that may require additional open or endoscopic urologic surgery.

As with any surgery, atelectasis is the most common complication of stone surgery. Aggressive incentive spirometry and patient ambulation assist in treating this complication. Some advocate a brief period of hyperventilation with vigorous lung expansion immediately postoperatively while the patient is supine and just prior to extubation.

Other complications include urine leak or urinoma, urinary fistula (to skin or bowel), bleeding, arteriovenous malformations, pseudoaneurysms, and injury to pleura/lung with pneumothorax. The vast majority of cases with urinary leakage and fistula between the collecting system and skin can be treated with a ureteral stent; percutaneous placement of a perinephric drain may be needed if an intraoperative drain was not placed or has already been removed at the time the leak is recognized. An indwelling urethral catheter may also be needed to divert the flow from the fistula tract and allow it to seal.

A small pneumothorax without respiratory distress due to an iatrogenic pleural injury can usually be treated conservatively and monitored. Larger air pockets can be treated with aspiration or a chest tube. If a lung injury is also present, a chest tube should be the initial therapy.

Fistula with the bowel can sometimes be managed with a stent, urethral indwelling catheter, bowel rest, and parenteral nutrition. If the fistula does not respond to this conservative management, surgical repair and possible nephrectomy and/or bowel resection may be necessary.

Bleeding, arteriovenous malformations, and pseudoaneurysms can be severe problems that may require embolization, emergent surgical intervention, transfusion, possible loss of the kidney, and even loss of life in extreme cases.

While the stone-free rates after pyelolithotomy are excellent for solitary renal pelvic stones, the morbidity is so much greater than even multiple percutaneous, ureteroscopic, and/or extracorporeal shockwave approaches that this procedure is rarely used. Urologists practicing before the advent of these technologies or in areas with little access to the complex instrumentation for noninvasive stone management have the most experience and best surgical results.

Note that patients should be informed about kidney stone prevention metabolic analysis, including a 24-hour urine collection for calcium, citrate, oxalate, magnesium, phosphate, sodium, uric acid, and total volume analysis. Optimally, a screening blood test for hypercalcemia, hyperparathyroidism, and hyperuricemia should also be performed. Testing protocols are available commercially from Dianon Systems (Stratford, Conn), UroCor Labs (Oklahoma City, Okla), LabCorp (Burlington, NC), and other laboratories.

Because of the advent of extracorporeal shockwave lithotripsy (ESWL) and percutaneous nephropyelolithotomy (PCN), pyelolithotomy is becoming an uncommon surgery in most developed countries. Pyelolithotomy is invasive, but it continues to have role in certain cases due to the size or shape of the stone, inaccessibility to ESWL and PCN, or the need for concomitant open surgical intervention for related problems.

Laparoscopic/robotic pyelolithotomy has growing support, especially when laparoscopic reconstruction of a UPJ obstruction is planned. ^{[7, 8, 9, 6]}