Cop+Ed+fisse 2006 91Archivio Italiano di Urologia e Andrologia 2022; 94, 1 ORIGINAL PAPER No conflict of interest declared. expanded significantly (2). Today, they are almost con- sidered a standard and indispensable urological tool. Ureteral obstruction is a complex and heterogeneous clin- ical condition therefore determining the ideal decompres- sion method can be challenging for urologists. These obstructions may develop owing to malignant or benign aetiologies. Malignancy that leads to this type of complex obstruction may originate from organs external to the uri- nary system as colorectal or gynaecological tumors or from organs internal to urinary system such as bladder and prostate cancers (3) (Figure 1). The aetiology of benign ureteral obstructions can be intra- ureteral or extra-ureteral. Intra-ureteral causes are the result of various pathologies such as ureteropelvic junc- tion obstruction, impacted chronic ureteral stones or stric- tures after recurrent endoscopic interventional proce- dures. Extra-ureteral benign obstructions may be caused by the obstetric causes, uterine leiomyomas or retroperi- toneal fibrosis (4). In cases of malignancy that cause severe ureteral obstruc- tion, the benefits of draining the upper urinary system include symptomatic relief, preservation and mainte- nance of renal function, reduction of hospital stay and minimisation of the negative effects on the patient's qual- ity of life (3-5). However, there is still no clear guideline on ideal meth- ods for how to free urinary flow in the management of ureteral obstructions (6). In patients without lower uro- genital system pathologies and active urinary tract infec- tion, retrograde ureteral stenting can be used as an alter- native for long-term ureteral obstruction or fistula treat- ment. The JJ stents used in this procedure are normally inserted in a retrograde approach by using a guidewire placed by cytoscopic or ureterorenoscopic method (1). However, in this approach, it is sometimes not possible to advance the guidewire proximally to the site of obstruction due to technical shortcomings, especially in patients with anatomical dislocation of the bladder wall, abnormally localised ureteral orifice by the tumor or in patients with malignant obstruction involving a long ureteral segment. In addition, retrograde ureteral stenting can sometimes be difficult or even unsuccessful in patients with obstruc- Objective: The aim of the present study was to examine the results of antegrade JJ stent placement in upper urinary tract obstruction in patients where retrograde placement was not possible. Methods: In this retrospective study, patients who underwent antegrade JJ stent placement for malignant ureteral obstruction in the urology clinic of a university hospital between January 1, 2018 and December 31, 2020 were included in the study. JJ stent was placed under local or general anaesthesia guided by ultrasonography and fluoroscopy. Age, gender, kidney function values, pathologies causing obstruction, and complications of the patients were examined. Results: In this study, 40 patients (16 men, 24 women) who underwent antegrade JJ stent placement were included. The mean ages of the women and men included were 51 (31-91) years and 62.5 (26-81) years, respectively. In all, antegrade JJ stenting was performed in 61 renal units of these patients. Of these, 21 were bilateral, 11 in the right collecting system and 8 in the left collecting systems. Clinical and technical success was achieved in 59 of the 61 procedures (96.6%). Arteriovenous fistula developed in only one patient, whereas no serious compli- cations such as massive bleeding, resistant hematuria or pseudoaneurysm occurred in the remaining patients. The proce- dure was completed in a mean time of 15-30 minutes. Conclusions: Antegrade JJ stent placement is a procedure with a high success rate and low risk of complications that can be used in patients with severe ureteral obstruction owing to malignant or benign aetiologies. This method should be applied in centres experienced in malignant ureteral obstruction and on patients where retrograde placement was not possible. Furthermore, it should be considered as an alternative treatment option to open surgery as it can be performed under local anaesthesia in patients at a high risk of anaesthesia. KEY WORDS: Malignant ureteral obstruction; Obstructive uropa- thy; Genitourinary neoplasms; Antegrade JJ stenting. Submitted 9 March 2022; Accepted 16 March 2022 INTRODUCTION Ureteral stents were first developed by Zimskind et al. (1) in 1967 and have since been used in the treatment of ureteral obstruction or various urogenital fistulas. Over time, indications of the use of ureteral stents have Antegrade placement of JJ catheter in the treatment of malignant ureteral obstruction: Retrospective analysis of a single centre Eser Ordek 1, Mehmet Kolu 2, Mehmet Demir 3, Bulent Kati 3, Eyyup Sabri Pelit 3, Ismail Yagmur 3 1 Kahta State Hospital, Urology Department, Adiyaman/Turkey; 2 Harran University, Faculty of Medicine, Radiology Department, Sanliurfa, Turkey; 3 Harran University, Faculty of Medicine, Urology Department, Sanliurfa, Turkey. DOI: 10.4081/aiua.2022.1.91 Summary Archivio Italiano di Urologia e Andrologia 2022; 94, 1 E. Ordek, M. Kolu, M. Demir, B. Kati, E. Sabri Pelit, I. Yagmur 92 tive malignancy in the lower urogenital system, those who undergo urinary diversion surgery with ileal con- duit, or patients with anatomical changes due to renal transplantation (7). In addition, retrograde ureteral stent- ing is usually performed under spinal or general anaes- thesia that can be associated to serious complications and may be contraindicated in high-risk comorbid patients. In such cases, the best option is a permanent percuta- neous nephrostomy or the placement of an ureteral JJ catheter in an antegrade manner with a percutaneous approach (8). Percutaneous nephrostomy is a minimally invasive treat- ment option commonly used in the treatment of acute hydronephrosis, which aims to maintain existing renal function by providing drainage of intra-renal content. Although percutaneous nephrostomy is a very useful and feasible method, it has certain disadvantages compared to antegrade JJ stenting such as a more negative effect on patient comfort, a high risk of infection and easy disloca- tion of the catheter (8-9). Antegrade JJ stenting is a minimally invasive alternative treatment technique (8) that is described by several stud- ies in the literature. The aim of the present study was to provide a retrospec- tive analysis of antegrade JJ stenting results in a patient population with malignant ureteral obstruction who could not undergo retrograde JJ stenting in a tertiary health centre. MATERIALS AND METHODS Patient selection Ethical approval was obtained from the local ethics com- mittee for the study (Decision no: HRU/21.11.29). The data were obtained from electronic medical records, diagnostic imaging and laboratory examinations of patients who underwent JJ stenting due to malignant ureteral obstruction in the urology clinic of our hospital between January 1, 2018 and December 31, 2020. Patients with ureteral obstruction who underwent retro- grade JJ stenting with conventional technique were exclud- ed from the study. Conversely, patients who could not undergo retrograde JJ stenting or who previously had per- cutaneous nephrostomy were included in the study. Antegrade JJ stenting procedures were performed with the guidance of a specialist interventional radiologist by a urol- ogist with clinical experience. Absolute contraindications for antegrade JJ stenting included uncorrectable coagulopa- thy, severe vertebral bone and posture disorders, insuffi- cient cardiopulmonary function, hemodynamic instability, pregnancy and severe uncontrolled hypertension. Antegrade JJ stenting technique After receiving informed consent from the patient or first- degree patient relatives, the preoperative preparation process was completed. All patients were given preopera- tive iv (intravenous) antibiotic prophylaxis. All invasive procedures were performed under local or general anaes- thesia by ultrasonography and fluoroscopy. After the patient was prepped, the procedure was usually per- formed in two stages. Percutaneous nephrostomy was first performed on patients who did not have previous nephrostomy. Then, in the same session, ureteral JJ stent was placed in the renal pelvis and ureter and by antegrade method. The patient was placed in the prone position and surgical area was sterilised. An 18-gauge-15 cm Chiba needle was used under the guidance of fluoroscopy and ultrasound, which ensured proper placement from the skin to the renal calyx with Seldinger technique (10). The location of renal puncture was determined in accor- dance with the access indication taking into account anatomical constraints (5-10). Punctures were normally performed using the posterolateral oblique approach to the upper collecting system along Brödel's avascular plane, through the safest and easiest access to the uretero- pelvic system (Figure 2). Figure 1. 3 × 3 × 4 cm bladder tumour localised to the left lateral- bladder base that completely covers the left orifice (indicated by the arrow sign). Figure 2. Schematic drawing of the kidney avascular plane, also known as the Brödel line. A: Magnification of the angle of entry of the needle into the right kidney, with the patient in the supine position. B: Axial slice obtained with the patient in the prone position, demonstrating the ideal entry point for the percutaneous nephrostomy (Reference 5). 93Archivio Italiano di Urologia e Andrologia 2022; 94, 1 Antegrade placement of JJ stents The needle was placed in the renal calyx selected by ultra- sonography and a urine sample was collected and sent for urinalysis. After the needle was properly positioned, ante- grade pyelography was performed with injection of non- ionic iodised contrast agent (350 mg I/mL) diluted with sterile saline in a ratio of 1/2 in order to reveal the col- lecting system anatomy fluoroscopically (Figure 3). All sort of pathologies such as obstruction, stenosis or extravasation in the ureter were verified. (Figure 4). According to the Seldinger technique, a 6 F introducer was placed towards the ureteropelvic junction. Using a hydrophilic 0.035-inch guidewire under serial scopy images, the 5 F diagnostic catheter was advanced by pass- ing the obstruction site in the ureter and placed in the bladder. Hydrophilic guidewire was removed and a 0.035-inch J-tip teflon-coated guidewire was inserted into the bladder (Figure 5). The 5 F catheter was then removed and replaced with a 6 Fr × 45 cm introducer sheath. The JJ catheter was advanced with the help of the teflon-coated guidewire or with the help of the sheath dilator feeding on the intro- ducer sheath without the guidewire, until the distal end of the stent entered the bladder. The introducer sheath was then pulled back onto the dilator until the sheath remained only in the renal pelvis. At this point, with the help of the dilator, the proximal (renal) tip of the JJ catheter was advanced to the appropriate position within the collecting system. Serial scopy images were obtained to confirm that the tip of JJ stent was curled in the blad- der and renal pelvis (Figure 6). Then, a 6 F percutaneous nephrostomy catheter was placed in the renal pelvis under the guidance of fluo- roscopy and fixed to the skin. Abdominal ultrasonography was planned for all patients to exclude possible complications after antegrade JJ stent- ing. On postoperative day 1, DUSG (direct urinary sys- tem radiography) was done to observe the position of the JJ catheter and the excretion of the contrast agent used. The nephrostomy catheter of the patients who did not have major complications and who did not have severe hematuria was removed in the postoperative 1-2 days under the guidance of floroscopy. The correct placement of the ureteral stent and the completion of the interven- tional procedure without major complications was con- sidered as technical success. Clinical success was defined Figure 3. Right antegrade pyelography. Figure 4. Right antegrade pyelography, narrow segment in proximal urethra and antegrade advancement of guide (indicated by the arrow sign). Figure 5. Antegrade placement of the guidewire and curling in the bladder (indicated by the arrow sign). Figure 6. JJ and nephrostomy catheter placed by left antegrade percutaneous approach. Archivio Italiano di Urologia e Andrologia 2022; 94, 1 E. Ordek, M. Kolu, M. Demir, B. Kati, E. Sabri Pelit, I. Yagmur 94 as decreased blood creatinine levels to normal values, resolved hydronephrosis and complete recovery or decrease in symptoms in postop follow-ups. RESULTS During the study, antegrade JJ stenting procedure was performed on 40 patients (16 males, 24 females) who presented to our clinic. The mean age of the patients was 56.7 years. In all, antegrade JJ stenting was performed in 61 renal units of these patients. Of these, 21 were bilater- al, 61 were in the right collecting system and 8 in the left collectinf system. Clinical and technical success was achieved in 59 of the 61 procedures (96.6%). Severe obstruction was caused by malignant causes (blad- der-prostate and colorectal cancers, among others) in 34 (85%) of the patients, whereas 6 (15%) had benign eti- ologies (C-section and ureteroenoscopic interventions, among others) (Table 1). The clinical and technical suc- cess rate in the patients was 96.3% and 100% for neo- plastic and non-neoplastic groups, respectively. In addition, 14 (35%) of the patients had important comorbidities such as coronary artery disease, cere- brovascular disease, diabetes and hypertension. In 33 patients that include those with high anaesthesia risk, the procedure was performed under local anaesthesia, while general anaesthesia was used in 7 patients. The mean blood creatinine values decreased from a preoperative value of 2.3 mg/dl to 1.1 mg/dl after the procedure. In addition, the preoperative kidney antero-posterior (AP) diameter decreased from an average of 25.15 mm to 14.02 mm during postoperative follow-up. In two of the patients with bladder cancer aetiology, malignant ureter- al obstruction could not be corrected due to lack of bal- loon dilatation material in our hospital and antegrade JJ stenting could not be performed. Therefore, percuta- neous nephrostomy was performed (Table 2). When the past clinical records of the patients were exam- ined, it was determined that 14 patients had a history of retrograde JJ stenting and 17 had a history of percuta- neous nephrostomy (Table 3). In the present study, ante- grade JJ stenting was performed through the existing nephrostomy in only three patients. During the follow-up, 75% of the patients developed clinically insignificant minimal haematuria, while almost all patients had pain at the wound site that resolved with simple analgesic treatment. The percutaneous nephrosto- my catheter was fixed to the opening site for an average of 24-48 hours until the haematuria was completely resolved. Haematuria recovered spontaneously within a few hours, usually without the need for additional inter- vention. In one patient with colorectal malignancy, arte- riovenous fistula, which can be con- sidered a major complication, developed and the necessary treat- ment with angioembolisation was performed. No other patient devel- oped serious complications such as bleeding, resistant haematuria, arte- riovenous fistula or pseudoa- neurism requiring transfusion. Control DUSG taken on postopera- tive day 1 was checked to ensure that JJ stents were in the correct localisation. JJ stents were usually removed and new stents were placed within an average of 3 months. The procedure was per- formed either cystoscopically or Table 1. Patient distribution according to benign and malignant etiologies. Malignancies 34 patients 85.0% Endometrium carcinoma 5 12.5% Colorectal carcinoma 8 20.0% Bladder cancer 10 25.0% Prostate cancer 1 2.5% Ovarian carcinoma 1 2.5% Cervix carcinoma 4 10.0% Soft tissue carcinoma 5 12.5% Benign causes 6 patients 15.0% Surgical ligation (caesarean section) 3 7.5% Ureteral stone (ureterorenoscopy) 3 7.5% Total 40 patients 100.0% Table 3. History of retrograde JJ and percutaneous nephrostomy according to aetiology. Retrograde Percutaneous JJ history nephrostomy history Malignancies ! x ! x Endometrium carcinoma 0 5 0 5 Colorectal carcinoma 3 5 3 5 Bladder cancer 4 6 6 4 Prostate cancer 2 2 2 2 Ovarian carcinoma 1 0 1 0 Cervix carcinoma 1 4 2 3 Soft tissue carcinoma 0 1 0 1 Benign causes ! x ! x Surgical ligation (caesarean section) 3 0 0 3 Ureteral stone (ureterorenoscopy) 0 3 3 0 Table 2. Aetiology of malignant urological obstructions, together with the distribution of approaches, technical success, failures and complications. Indication Patients Unilateral Bilateral Technical Technical Complications approach approach success failure Endometrium carcinoma 5 (12.5%) 2 3 5 __ __ Colorectal carcinoma 8 (20.0%) 3 5 8 __ 1 Bladder cancer 10 (25.0%) 5 5 8 2 __ Prostate cancer 4 (10.0%) 2 2 4 __ __ Ovarian carcinoma 1 (2.5%) __ 1 1 __ __ Cervix carcinoma 5 (12. 5%) 1 4 5 __ __ Soft tissue carcinoma 1 (2.5%) __ 1 1 __ __ Surgical ligation (caesarean section) 3 (7.5%) 3 __ 3 __ __ Ureteral stone (ureterorenoscopy) 3 (7.5%) 3 __ 3 __ __ 95Archivio Italiano di Urologia e Andrologia 2022; 94, 1 Antegrade placement of JJ stents ureterorenoscopically using a retrograde technique with guide wire. Procedures were completed between 15-30 minutes on average. DISCUSSION Ureteral obstructions may occur due to malignant or benign etiologies. In ureteral obstruction, options such as percutaneous nephrostomy or ureteral stenting are the most commonly used treatment methods (12). In the cur- rent retrospective study, we investigated the applicability of percutaneous antegrade ureteral stenting in the treat- ment of severe ureteral obstructions caused by both malignant and benign causes and we found that ante- grade stenting is a safe and effective method in cases where the retrograde approach fails. Since both acute and chronic ureteral obstruction can cause impairment of renal function, these conditions may lead to severe mor- bidities. In addition, there is still no clear consensus in the literature on the treatment of malignant ureteral obstruction regarding the patient's clinical picture, emer- gency status, current technical equipment, or clinician's experience (6-11). The treatment method to be selected is usually determined depending on the physician's person- al clinical experience, capabilities of the institution and patient preference (12). Percutaneous nephrostomy has various risks such as wound site and urinary tract infection due to mandatory external drainage bag, and it also negatively affects the daily life and comfort of the patient (9). Ureteral JJ stents are usually placed under cystoscopy with a retrograde approach in various obstruction cases. However, they have been successfully placed with ante- grade approach by many years. Both techniques are promising and give similar long-term results, but in recent studies, the failure rates of retro- grade ureteral stenting in malignant ureteral obstruction has been reported to range between 18.5% and 42% (12- 13-14). In addition, numerous studies have investigated the applicability of antegrade ureteral stenting (15-16). In addition to similar long-term results, both techniques have their advantages and disadvantages. Using a retro- grade appoach, it is possible to simultaneously treat con- comitant bladder and ureteral stones with endoscopic laser or pneumatic lithotripter or to take a punch biopsy sample from possible malignancies, or to expand existing strictures and relieve obstruction. Retrograde ureteral stenting is a one-step procedure but it has the disadvan- tage to be performed under general or spinal anaesthesia in operating room conditions (2-17). Particularly, gener- al anaesthesia is a problem in patients with serious car- diac reserve or respiratory problems, and it is even con- traindicated in some cases. In addition, in severe ureteral obstructions caused by malignant etiologies, factors such as external ureteral pressure or bladder invasion reduce the success rates of retrograde stenting method by up to 50% (7-15). Clinical trials and observations have proven that ante- grade ureteral stenting has higher success rates in severe ureteral obstructions due to both malignant and benign etiologies. Success rates reported in the literature range from 80% to 92% (17-18). In addition, balloon dilatation can be performed during antegrade ureteral stenting, increasing technical success rates significantly. Furthermore, antegrade ureteral stenting can be per- formed successfully even under local anaesthesia, as opposed to retrograde method (18). In the present study, clinical and technical success with the antegrade method was 96.6% and the success rate was consistent with the literature. In only two procedures, percutaneous nephrostomy has to be performed because JJ stent could not be inserted by antegrade method. Major complications associated with antegrade JJ stenting have been reported in the literature, but these occur in only 4-8% of cases (10). These complications include retroperitoneal bleeding, which can be treated with angiographic embolisation, perforation of the pleura or intraabdominal organs (such as intestine, liver, spleen) and urosepsis (8-19). Significant respiratory complica- tions such as pneumothorax, hydrothorax and empyema are seen in less than 0.2% of patients (6). Minor complications such as the extravasation of urine into the retroperitoneal area, subcapsular hematoma and macroscopic hematoma can develop in 3-15% of cases (20). Mild haematuria caused by urothelial irritation is a common finding after ureteral stenting and usually improves spontaneously during follow-up. However, in the presence of severe and resistant haematuria that develops after the placement of ureteral stent, ureteroar- terial fistula between the ureter and the major or internal iliac artery should be considered first and necessary inter- ventions should be performed quickly (6). The clinician's mastery of urinary system anatomy and vascularisation is vital in choosing a safe pathway for per- cutaneous puncture and reducing the risk of complica- tions (8-10-11). In the present study, only 3 (7.5%) of the patients developed minor complications including mild lumbar pain and minimal haematuria (Clavien Degree I), which usually recovered spontaneously within hours. Only one patient developed arteriovenous fistula, which is considered a major complication, and the necessary treatment was performed with angioembolisation. In addition, although parenteral antibiotic prophylaxis is applied to all patients before the procedure, urinary tract infection is also a common finding. However, usually these infections can be successfully treated with basic antibiotics. However, if the current infection does not respond to med- ical pharmacological treatment, JJ stents may need to be removed immediately. In the present study, no symptoms of urinary tract infection that required stent removal was observed in any of the patients. The present study has certain limitations. Firstm the study was designed and conducted retrospectively. Furthermore, the interventional radiology clinic in our hospital has just become operational, therefore the num- ber of patients was limited. It becomes evident that the most important requirement at this stage is the clinical skill of an expert interventional radiology specialist. CONCLUSIONS The results of this retrospective study show that percuta- neous antegrade JJ stenting is possible in ureteral obstruc- tion caused by both malignant and benign causes with Archivio Italiano di Urologia e Andrologia 2022; 94, 1 E. Ordek, M. Kolu, M. Demir, B. Kati, E. Sabri Pelit, I. Yagmur 96 minimal risk of complications and high technical success rate. In addition, antegrade JJ stenting stands out as a good alternative option when conventional retrograde placement fails. To the best of our knowledge, there are no large-scale randomised controlled clinical trials in the literature comparing antegrade ureteral JJ stenting with retrograde JJ stenting. In addition, there is still no clear consensus in the literature on the treatment of malignant ureteral obstruction regarding the patient's clinical pic- ture, emergency status, current technical equipment, or experience of the interventional radiologist. Therefore, in patients with malignant ureteral obstruction, randomised controlled trials with a larger population are needed to gain further information on the optimal approach to ureteral JJ stenting. REFERENCES 1. Zimskind PD, Fetter TR, Wilkerson JL. Clinical use of long-term indwelling silicone rubber ureteral splints inserted cystoscopically. J Urol. 1967; 97:840-4. 2. Seymour H, Patel U. Ureteric stenting: Current status. 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Quality Improvement Guidelines for Percutaneous Nephrostomy. J Vasc Interv Radiol. 2016; 27:410-4. 20. Ganatra AM, Loughlin KR. The management of malignant ureteral obstruction treated with ureteral stents. J Urol. 2005; 174:2125-8. Correspondence Eser Ordek, MD (Corresponding Author) dr_eseser@hotmail.com Kahta State Hospital, Urology Department 02000Adiyaman (Turkey) Mehmet Kolu, MD drrdylg@gmail.com Harran University, Faculty of Medicine Hospital, Radiology, 63340 Sanliurfa (Turkey) Mehmet Demir, MD drdemir02@gmail.com Bulent Kati, MD bulentkati@harran.edu.tr Eyyup Sabri Pelit, MD dreyyupsabri@hotmail.com Ismail Yagmur, MD dr_iyagmur@hotmail.com Harran University, Faculty of Medicine Hospital, Urology, 63340 Sanliurfa (Turkey)