Abstract: To investigate the value of percutaneous renal fine needle aspiration melanoma test in the diagnosis of ureteric fistula. Methods: The clinical data of 54 cases of ureteric fistula were retrospectively analyzed. In all cases, percutaneous renal fine needle aspiration merocyanine test was performed at the end. The results: 42 cases had IVP or enhanced CT suggesting lateral ureteral fistula, among which one case was confirmed as right ureteral fistula by percutaneous fine needle aspiration melanoma test although both IVP and enhanced CT suggested left ureteral fistula. 12 patients had IVP or enhanced CT unable to determine lateral ureteral fistula, among which 4 cases had no kidney visualization, 5 cases had faint kidney visualization and delayed visualization still did not show, 3 cases had upper urinary tract visualization The diagnostic accuracy of IVP was 75.9% (41/54) and 100% (54/54) by percutaneous renal fine needle aspiration merocyanine test. All cases were cured by patency negative pressure drainage, PCN urinary flow diversion or second stage surgery. CONCLUSION: IVP or enhanced CT is an effective method to diagnose ureteral fistula, but there are some limitations. The percutaneous renal fine needle aspiration melanoma test is a simple, accurate and non-radiological method for the diagnosis of ureteric fistula, and can be used as a routine method for the diagnosis of ureteric fistula, and can provide important guidance information for effective percutaneous nephrostomy drainage. Ureteral fistula is one of the common complications of urology, obstetrics and gynecology and general surgery. Urine leaks out of the fistula and forms urinary cysts, which cause secondary infection, perifistulitis, pyelonephritis, peritonitis, etc. Fibrosis and scarring of the tissue around the fistula leads to ureteral stenosis, complicating hydronephrosis and, in severe cases, renal failure, causing great harm to the patient. Intravenous urography has some value in diagnosing ureteral fistula and determining the fistula of the affected ureteral orifice, but there is radiological damage. We applied percutaneous renal fine needle puncture melanoma test to diagnose ureteric fistula and on this basis, we treated some cases with percutaneous nephrostomy for drainage and achieved satisfactory results. The results are reported as follows: 1. Data and methods: 1.1. Clinical data From 2000-7-1 to 2008-12-31, 54 cases of ureteral fistula were admitted to our hospital. 25 cases were uretero-ileal anastomotic fistula after total cystectomy with Bicker ileocecal cystectomy, 10 cases were uretero-ileal neobladder anastomotic fistula after in situ Studer ileo-neobladder, 5 cases were after general surgery urinary fistula, and 14 cases were post-obstetric and gynecological surgeries, of which 5 cases were post-operative intravaginal leaks. There were 30 male and 24 female cases in this group, with a mean age of 62 years (40-70). Intravenous phelography (IVP) was routinely performed in all cases, and in some cases, enhanced CT was also performed to determine the affected ureteral fistula. In all cases, percutaneous renal fine needle aspiration Meridian test was performed. 1.2 Methods Based on the ureteral fistula on the side of the lesion shown by IVP and enhanced CT, percutaneous renal puncture was performed on that side. If it is difficult to determine the side of the lesion, percutaneous renal puncture will be performed from the side of the kidney that is not visualized, delayed visualization or severe hydronephrosis according to IVP or CT performance, and then from the opposite side if necessary. Specific method: The patient is placed in prone position, routinely disinfected and toweled, and after local anesthesia, under ultrasound localization and guidance, the G18 trocar is punctured into the pelvis and calyces of one side via the scapular line under twelve ribs, and urine flow is seen to confirm the successful puncture. Slowly inject 50ml of melphalan into the renal pelvis, and observe whether there is any melphalan outflow in the negative pressure drainage tube or vagina. If no melanoma was seen in the drainage tube or vagina, the same method was used to perform the puncture melanoma test in the contralateral kidney. 2. results Among 54 cases, 42 cases of IVP or enhanced CT suggested ureteral fistula, among which 41 cases were confirmed by PCN puncture melanoma test, but in one case, although both IVP and enhanced CT suggested left ureteral fistula, no melanoma was seen in the drainage tube after left PCN puncture and melanoma injection, and melanoma was seen in the drainage tube after right PCN puncture and melanoma injection instead. 42 cases, 25 cases of left ureteral fistula were confirmed by PCN puncture and melanoma injection, and melanoma was seen in the drainage tube. In 12 cases, the IVP or enhanced CT could not determine the lateral ureteral fistula, among which 4 cases had no renal visualization, 5 cases had faint renal visualization and delayed visualization, and 3 cases had good visualization of the upper urinary tract, but could not distinguish the lateral ureteral fistula. 12 cases with no IVP visualization were clearly diagnosed as lateral ureteral fistula by performing percutaneous renal fine needle puncture with melanoma. The fistulas were clearly diagnosed by percutaneous renal fine needle aspiration with US blue test. The diagnostic accuracy of IVP was 75.9% (41/54), and the percutaneous fine needle aspiration Meridian test was 100% (54/54). 35 of the 54 cases were followed up for an average of 1.4 months (1 to 3 months) with a clear negative pressure drainage, and the ureteral fistula was healed. 5 cases of ureterovaginal fistula and 14 cases with poor local drainage were treated with a lateral PCN aspiration. In 5 cases of ureterovaginal fistula and 14 cases with poor local drainage, PCN puncture and drainage was performed on the affected side. 11 cases were followed up for 1.58 months (1 to 3 months) on average, the negative pressure drainage flow was significantly reduced and the vaginal leakage disappeared, and the negative pressure drainage tube and PCN tube were removed and the fistula was cured. 8 cases were followed up for 3 months with no significant improvement of the fistula, and the ureteral bladder reimplantation on the affected side was performed at the second stage and the fistula was cured. 3. Discussion: 3.1. The etiology of ureteral fistula Ureteral fistula is one of the common complications of urology, obstetrics and gynecology and general surgery. Urine leaks from the fistula, forming urinary cysts, secondary infection, causing perifistulitis, pyelonephritis, peritonitis, fibrosis and scarring of the tissue around the fistula, leading to ureteral stenosis, complicating hydronephrosis, and in severe cases leading to renal failure, causing great harm to patients. Urological ureteral fistulas are mostly seen in patients who underwent ileal cyst or ileal neobladder after total cystectomy, with urinary fistulas at the ureteral ileal anastomosis predominating. Its incidence is reported in the literature to be about 0.8% to 12.5%. The main reasons for this are the following: ① excessive tension in the uretero-ileal anastomosis, which is related to the short free length of the ureter; ② excessive stripping of the tissue around the ureteral epithelium, which affects the ureteral blood supply and causes ischemic necrosis and poor healing of the uretero-ileal anastomosis; ③ poor suturing of the uretero-ileal anastomosis, which is not mucosa-to-mucosa anastomosis. According to the literature, the incidence of ureteral injury in gynecologic surgery ranges from 0.03% to 2.2%. During gynecologic surgery, ureteral injury generally occurs when the uterine artery is severed, when the ureteral tunnel is treated during radical total hysterectomy, or during pelvic lymph node dissection, either by cutting, or clamping, or suturing on, or by damaging ureteral blood flow. These include: ① at the pelvic funnel ligament; ② at the uterine artery crossing the ureter; and ③ at the uterosacral ligament. In general surgery, low anterior resection of rectal cancer and combined abdominoperineal resection, as well as the separation and dissection of ascending and descending colon cancer located in the posterior side of the intestinal wall and infiltrating into the retroperitoneum are very likely to damage the ureter, especially when the left ureter is often lifted by the sigmoid mesentery and easily damaged when the root of the sigmoid mesentery is freed. Preoperative ureteral cannulation helps to accurately identify the ureter intraoperatively and effectively avoid ureteral injury in obstetrics and gynecology and general surgery. 3.2. Diagnosis of ureteral fistula According to the increase of postoperative negative pressure drainage and creatinine measurement of drainage fluid, the diagnosis of ureteral fistula is simple, but other auxiliary examinations are still needed to determine the location and size of ureteral fistula. Intravenous urography has long been the most widely used method for detecting ureteric fistulas. Venous urography reveals the location of the fistula, the size of the fistula, the extent of the fistula, and the combined presence of obstruction in 61% to 95% of cases. However, when the affected kidney is decompensated or lost, the concentration of upper urethral contrast is insufficient or the fistula is narrowed by fibrosis, IVP often does not show well, and even high-dose intravenous urography is difficult to accurately determine the location of the ureteral fistula, which makes follow-up treatment difficult. Delayed CT enhancement, especially spiral CT 3D reconstruction, is currently the gold standard for diagnosing ureteral injury and can accurately determine the location and extent of ureteral fistula, but its radiological damage and expensive examination cost limit its clinical application. In our data, the accuracy of IVP in diagnosing ureteral fistula was 75.9%, and in one case, both IVP and CT suggested left-sided ureteral fistula, but percutaneous renal fine needle aspiration melanoma test confirmed right-sided ureteral fistula, which shows that IVP or CT has some limitations in determining the site of ureteral fistula lesion, and it is necessary to perform percutaneous renal fine needle aspiration melanoma test to clarify the site of ureteral fistula and guide effective treatment. In the present study, we applied ultrasound localization of percutaneous renal fine needle aspiration merocyanine test to diagnose ureteric fistula with 100% accuracy. This method is simple to operate, ultrasound positioning can avoid damage to adjacent organs such as pleura and intestine during puncture, 18G fine needle puncture has little damage, mereblue has no risk of contrast allergy, no radiological damage during operation, few complications, high diagnostic accuracy, and supporting equipment is easy to obtain and easy to promote, which has not been reported in the literature at home and abroad. 3.3. Treatment of ureteral fistula The failure rate of one-stage surgical repair of fistula is high because the patient’s general condition has not recovered, the tissue in the original surgical area is edematous and adherent, and the local anatomical level is unclear. Adequate urinary diversion, open fistula, and reduction of tissue edema and inflammatory response around the fistula can help to repair and heal smaller fistulas and reduce the difficulty of second-stage surgery. We believe that paralleling percutaneous nephrostomy drainage is a good way to reroute urinary flow, with unobstructed drainage, few complications, rapid healing of the ureteral fistula after urinary rerouting, and little impact on renal function, while leaving a ureteral stent tube in paralleling can promote migratory repair of the ureteral epithelium, heal the fistula, and prevent ureteral stenosis. In addition, after three months of drainage by PCN, the edema of the tissues around the fistula subsides, and the second-stage surgery is feasible, with high success rate and low incidence of ureteral stenosis, and the surgical approach is based on ureteral bladder reimplantation. Tension-free anastomosis, mucosa-to-mucosa reconciliation, preservation of the ureteral epithelium, maintenance of good ureteral blood supply, and application of absorbable sutures to the anastomosis are the keys to successful uretero-vesical anastomosis, significantly reducing the risk of postoperative reureteral fistula and anastomotic stricture. In our data, among 19 patients who had PCN puncture and drainage, 11 cases were cured by patency drainage and urinary fistula; 8 cases were cured after second-stage ureterobladder reimplantation with satisfactory treatment results. Retrograde placement of ureteral stent tube under cystoscopy is a treatment option, but it is difficult to operate and has high surgical risk, which may aggravate ureteral injury and even lead to ureteral rupture, especially for patients who underwent ileal cystectomy after total cystectomy, the length of ileal bladder is long and the ureteral route is tortuous, so it is more difficult to place the tube via ileal bladder, which may lead to ureteral perforation and pseudo-tract formation and other risks. In summary, intravenous urography or enhanced CT examination has some value in diagnosing ureteral fistula, and is a routine clinical diagnosis method, but the diagnostic accuracy is 61% to 95%, and there is radiological damage at the same time. In contrast, percutaneous renal fine needle aspiration melanoma test is easy to perform, has a high diagnostic accuracy and no radiological damage, and can be used as a routine diagnostic method for ureteral fistula, and can provide important guiding information for effective percutaneous nephrostomy drainage for ureteral fistula.