Propensity score matched analysis of treatment outcomes in pediatric ureteropelvic junction obstruction: a comparison between horseshoe and non-horseshoe kidneys.

BACKGROUND: Pediatric hydronephrosis poses distinct challenges, particularly in cases involving horseshoe kidneys (HSK). This retrospective study compares treatment outcomes between HSK and non-horseshoe kidneys (NHSK) in pediatric ureteropelvic junction obstruction (UPJO) patients. METHODS: A retrospective cohort study included 35 patients with HSK and 790 patients with NHSK undergoing pyeloplasty. Preoperative, intraoperative, and postoperative parameters were evaluated. Propensity score matching (PSM) balanced patient characteristics in the NHSK group. RESULTS: In comparison with NHSK, HSK exhibited a higher crossing vessel incidence (51.6% vs. 5.12%, P < 0.001) and smaller preoperative anteroposterior pelvic diameter (APD). Post 6 and 12 months, NHSK maintained a larger APD, with a higher P/C ratio at 12 months. PSM retained significantly higher crossing vessel incidence in HSK (51.6 vs. 3.61%, P < 0.001). Laparoscopic pyeloplasty (LP) in HSK showed lower postoperative length of stay (LOS). Postoperative ultrasound parameters favored NHSK. In HSK and NHSK with crossing vessels, HSK demonstrated higher complications even post-PSM (38.5% vs. 0%, P = 0.039). CONCLUSIONS: The study emphasizes the importance of recognizing crossing vessels in HSK-related hydronephrosis. Surgical success, although comparable between HSK and NHSK, requires tailored approaches. This investigation contributes valuable insights to pediatric urology, emphasizing personalized management for optimal outcomes.

[A Case of Sigmoid Colon Cancer with Horseshoe Kidney].

We reported a case of sigmoid colon cancer with horseshoe kidney. A 79-year-old man had lower abdominal pain and underwent colonoscopy. The results of colonoscopy revealed sigmoid cancer. Preoperative computed tomography revealed horseshoe kidney. He underwent radical laparoscopic surgery. The histopathological diagnosis was pStage Ⅱa(The 9th Edition). He has not recurred 22 months later after operation. Surgery for colorectal cancer with congenital anomalies of the urinary tract requires attention to intraoperative secondary injuries. Therefore, preoperative evaluation using 3D-CT is useful tool for safety. Operating the proper dissecting normal layer would make safe laparoscopic operation possible without unexpected injuries.

Robot-assisted laparoscopic surgery for rectal cancer in a patient with a horseshoe kidney: A case report.

A 52-year-old, Japanese man presented to the hospital with a complaint of anal bleeding, and detailed examination resulted in a diagnosis of locally advanced rectal cancer. The patient underwent total neoadjuvant therapy followed by short-course radiation therapy and consolidation chemotherapy, which provided a partial response. After preoperative contrast-enhanced computed tomography showed a horseshoe kidney, robot-assisted, precise, laparoscopic, low anterior resection with D3 dissection and ileostomy construction was performed. The horseshoe renal isthmus was elevated surrounding the inferior mesenteric artery, and the left ureter and seminal vessels ran in front of the kidney. The hypogastric nerve traveled ventral to the horseshoe kidney. With robotic surgery, it was possible to perform more precise surgery while recognizing vascular and nerve anatomy in a rectal cancer patient with a horseshoe kidney due to good three-dimensional visibility and articulated forceps manipulation.

Laparoscopic retroperitoneal heminephrectomy for renal cell carcinoma in horseshoe kidney: a case report and review of the literature.

INTRODUCTION: In this case report, we demonstrate our technique of a retroperitoneal laparoscopic heminephrectomy for a T1b right hilar tumor in a horseshoe kidney. CASE PRESENTATION: A 77-year-old Vietnamese woman presented to the hospital because of right flank pain. On presentation, her serum creatinine was 0.86 mg/dL and glomerular filtration rate was 65.2 mL/minute/1.73 m2. According to her renal scintigraphy, glomerular filtration rates of the right and left moieties were 24.2 and 35.5 mL/minute, respectively. Computed tomography imaging demonstrated a 5.5 × 5.0 cm solid hilar mass with a cT1bN0M0 tumor stage was in the right moiety. After discussion, the patient elected a minimally invasive surgery to treat her malignancy. The patient was placed in a flank position. We used Gaur's balloon technique to create the retroperitoneal working space, and four trocar ports were planned for operation. Three arteries were dissected, including two arteries feeding the right moiety, one artery feeding the isthmus, and one vein, which was clipped and divided by Hem-o-lok. The isthmusectomy was performed with an Endostapler. Consequently, the ureter was clipped and divided. Finally, the whole right segment of the horseshoe kidney was mobilized and taken out via the flank incision. RESULTS: The total operative time was 250 min with an estimated blood loss of 200 mL. The patient's serum creatinine after surgery was 1.08 mg/dL, and glomerular filtration rate was 49.47 mL/minute/1.73 m2. The patient was discharged on postoperative day #4 without complication. Final pathologic examination of the tumor specimen revealed a Fuhrman grade II clear cell renal cell carcinoma, capsular invasion, with negative surgical margins. After a three-month follow-up, the serum creatinine was 0.95 mg/dL, and glomerular filtration rate was 57.7 mL/minute/1.73 m2. Local recurrence or metastasis was not detected by follow-up computed tomography imaging. CONCLUSIONS: Retroperitoneal laparoscopic heminephrectomy is a safe and feasible technique for patients with renal cell carcinoma in a horseshoe kidney and may be particularly useful in low income settings without access to robotic technology.

Supine mini percutaneous nephrolithotomy in horseshoe kidney.

OBJECTIVE: The percutaneous nephrolithotomy (PCNL) in Horseshoe kidneys (HSK) is usually performed in the prone position, allowing entry through the upper pole and providing good access to the collecting system. However, in patients with normal kidney anatomy, the supine position is reliable and safe in most cases, but it is unknown whether the supine position is adequate in patients with HSK. The purpose of this study was to describe the results of PCNL in HSK in three different surgical institutions and to evaluate the impact of supine position during surgery, comparing pre-operative and post-operative data, complications, and stone status after surgery. MATERIAL AND METHODS: Between 2017 and 2022, a total of 10 patients underwent percutaneous renal surgery for stone disease in HSK. All patients were evaluated pre- and post- operatively with non-contrast CT. we evaluated patients (age and gender), stones characteristics (size, number, side, site and density ), and outcomes. The change in haemoglobin, hematocrit, creatinine and eGFr were assessed between the most recent preoperative period and the first postoperative day. Procedure success was defined as stone-free or presence of ≤4 mm fragments (Clinically Insignificant residual Fragments - CIrF). Complications were registered and classified according to Clavien-dindo Grading System, during the 30 - day postoperative period and Clavien scores ≥ 3 were considered as major complications. Statistical analysis was performed using "r 4.2.1" software, with a 5% significance level. we also compared pre-operative and post-operative data using "wilcoxon signedrank test". RESULTS: No statistical difference was observed between preoperative and post-operative renal function data. At one post operative day CT scan, an overall success rate of 100% was registered. 9/10 patients were completely free from urolithiasis (stone-free rate: 90%), while 1/10 patients had ≤4 mm residual stone fragments (CIrF rate: 10%). No cases of intraoperative complications were registered. Post-operative complications were reported in 1/10 patients. A patient developed urosepsis (defined as SIrS with clinical signs of bacterial infections involving urogenital organs - Clavien-dindo Grade II) after procedure, and was treated with intravenous antibiotic therapy successfully.  Conclusions: This study shows that in patients with HSK mini- PCNL in supine position allows to achieve good stone free rate with a very low morbidity. According to our series, the described technique for PCNL in HSK should be an option. Nevertheless these results must be confirmed by further studies.

Implications of Tumor Surgery in Horseshoe Kidneys: A Comparative Study of Outcomes and Surgical Practices.

OBJECTIVE: To contrast surgical outcomes of Horseshoe Kidney (HSK) patients with localized renal masses suspected of cancer with nonfused nonectopic kidney patients, emphasizing safe surgical practices for HSKs. METHODS: The study examined solid tumors from the Mayo Clinic Nephrectomy registry between 1971 and 2021. Each HSK case was matched to three non-HSK patients based on various factors. The outcomes measured included complications within 30days of surgery, change in estimated glomerular filtration rate, and overall, cancer-specific, and metastasis-free survival rates. RESULTS: Thirty of the 34 HSKs had malignant tumors compared with 90 of the 102 patients in the nonfused nonectopic referent cohort. Accessory isthmus arteries were present in 93% of HSK cases, with 43% exhibiting multiple arteries and 7% with 6 or more arteries. Estimated blood loss and surgery duration were significantly higher in HSKs (900 vs 300 mL, P = .004; 246 vs 163 minutes, P < .001, respectively). The HSK group demonstrated an overall complication rate of 26% (vs 17% in referents, P = .2) and a median change in estimated glomerular filtration rate at 3months of - 8.5 (vs -8.1 in referents, P = .8). At 5-year follow-up, survival rates for HSK patients were 72%, 91%, and 69% for overall, cancer-specific, and metastasis-free survival, respectively. The corresponding rates were 79%, 86%, and 77%, respectively, for matched referent patients (P > .05). CONCLUSION: HSK tumor management is technically challenging with higher blood loss; however, the data demonstrate comparable outcomes for patients with HSK tumors, including complications and survival, to those without HSKs in experienced centers.

The role of retrograde intrarenal surgery in kidney stones of upper urinary system anomalies.

INTRODUCTION: Fusion, pelvic, and duplicated urinary tract anomalies of the kidney are rarely seen. There might be some difficulties in the stone treatment, in the administration of extracorporeal shockwave lithotripsy (ESWL), retrograde intrarenal surgery (RIRS), percutaneous nephrolithotomy (PCNL), and laparoscopic pyelolithotomy procedures in these patients due to the anatomical variations in kidneys with anomalies. AIM: To evaluate RIRS results on patients with upper urinary tract anomalies. MATERIALS AND METHODS: Data of 35 patients with horseshoe kidney, pelvic ectopic kidney, and double urinary system in two referral centers were reviewed retrospectively. Demographic data, stone characteristics, and postoperative characteristics of the patients were evaluated. RESULTS: The mean age of patients (n=35, 6 women and 29 men) was 50 years. Thirty-nine stones were detected. The total mean stone surface area in all anomaly groups was found to be 140 mm2, and the mean operative time was 54.7±24.7 minutes. The rate of using ureteral access sheath (UAS) was very low (5/35). Eight patients needed auxiliary treatment after the operation. The residual rate, which was 33.3% in the first 15 days, decreased to 22.6% in the third month follow-ups. Four patients had minor complications. In patients with horseshoe kidney and duplicated ureteral systems, it was observed that the risk factor increasing the presence of residual stones was the total stone volume. CONCLUSIONS: RIRS for kidneys with low and medium stone volume anomalies is an effective treatment method with high stone-free and low complication rates.

Retrograde intrarenal surgery for stones associated with renal anomalies: caliceal diverticulum, horseshoe kidney, medullary sponge kidney, megacalycosis, pelvic kidney, uretero-pelvic junction obstruction.

PURPOSE OF REVIEW: Nowadays, due to the increase of imaging diagnosis, we identify easily renal anomalies, and we can choose between a wide range of armamentarium to treat symptomatic stones in those challenging cases. However, there is a lack of evidence and consensus on its use. The aim of this narrative review is to collect all the available data about safety and efficacity of retrograde intrarenal surgery (RIRS) in the treatment of kidney stones associated to a renal anomaly. RECENT FINDINGS: Renal anomalies are uncommon findings and even more if it has to be associated with renal stones. After a literature review of the past 2 years, there are a small number of studies that compare the outcomes in patients who have been treated with minimally invasive modalities and they are mainly focus on RIRS. SUMMARY: It is of extreme importance to know the advances on the stone treatment in anomalous kidneys. With the development of new laser technologies, RIRS is becoming a more interesting technique with high success rate and safety. Further studies are needed to make an accurate statement about the adequate surgical technique for each renal anomaly and also, clinical trials using new laser technologies.

Nephron-sparing surgery for primary mucinous adenocarcinoma of renal pelvis in horseshoe kidney: A case report.

RATIONALE: Mucinous adenocarcinoma of the renal pelvis is extremely rare in malignancy of the renal pelvis, and <100 cases have been reported so far. However, horseshoe kidneys appear to be more prone to this mucinous gland metaplasia. Due to the lack of a specific diagnostic basis, it is difficult to confirm the diagnosis before surgery, which is easy to cause misdiagnosis. PATIENT CONCERNS: We report a 64-year-old male patient who found a cystic mass in the left kidney during physical examination. CT examination showed a horseshoe kidney with a cystic mass 9.5 × 8.0 cm in front of the left kidney, lacking obvious diagnostic features. DIAGNOSIS: It was misdiagnosed as cystic teratoma before the operation, and was diagnosed as mucinous adenocarcinoma of the renal pelvis through pathological examination after the operation. INTERVENTIONS: Resection of the tumor by nephron-sparing surgery and postoperative chemotherapy. OUTCOMES: No tumor recurrence was found at 6 years of follow-up. After 7 years, the patient had multiple metastases in the abdominal wall and peritoneum, and no tumor recurrence was found in the urinary system. The patient received chemotherapy again and survived well. LESSONS: The prognosis of nephron-sparing tumor resection for MRAP is not significantly different from that of radical nephroureterectomy + bladder cuff excision. Because it can reduce the risk that patients can not tolerate follow-up chemotherapy due to abnormal renal function after surgery, which may be more beneficial in patients with kidney abnormalities or chronic disease.

Robot-assisted modified bilateral dismembered V-shaped flap pyeloplasty for ureteropelvic junction obstruction in horseshoe kidney using KangDuo-Surgical-Robot-01 system.

PURPOSE: Horseshoe kidney (HSK) is the most common renal fusion anomaly, occurring in 0.25% of the population (1). It presents technical obstacles to pyeloplasty for ureteropelvic junction obstruction (UPJO) despite robotic assistance (2, 3). KangDuo-Surgical-Robot-01 (KD-SR-01), an emerging robotic platform in China, has yielded satisfactory outcomes in pyeloplasty (4, 5). We first describe our modified technique of robotic bilateral pyeloplasty for UPJO in HSK using KD-SR-01 system in the Lithotomy Trendelenburg position. MATERIALS AND METHODS: A 36-year-old man with HSK and bilateral UPJO suffered right flank pain due to renal calculi (Figure-1). Repeated double-J stent insertion and ureteroscopy lithotripsy did not relieve his symptoms. A robot-assisted modified bilateral dismembered V-shaped flap pyeloplasty was performed using KD-SR-01 system in the Lithotomy Trendelenburg position. RESULTS: Total operative time was 298 minutes with 50 ml estimated blood loss. There was no conversion to laparoscopic or open surgery. A follow-up of 14 months showed relieving symptoms and stable renal function. Cine magnetic resonance urography and computed tomography urography revealed improved hydronephrosis and good drainage. No intraoperative or postoperative complications occurred. CONCLUSIONS: It is technically feasible to perform a KD-SR-01-assisted modified bilateral dismembered V-shaped flap pyeloplasty in the Lithotomy Trendelenburg position for HSK. This procedure achieves managing UPJO on both sides without redocking the system and provides a wider operative field. In addition, it may be associated with better ergonomics, better cosmetic outcomes, and less possibility of postoperative bowel adhesion. However, further investigation is still warranted to confirm its safety, efficacy, and advantages over traditional procedures.

Laparoscopic nephron-sparing surgery for horseshoe kidney complicated with renal hemangioma: a case report and literature review.

In very rare cases, horseshoe kidney can present simultaneously with renal hemangioma. Nephron-sparing surgery (NSS) is a minimally invasive surgical procedure for horseshoe kidney with tumor, but it is difficult to operate and has not been reported. We report a 71-year-old female with imaging examination revealed an unexpected horseshoe kidney malformation and a cystic mass in the right kidney before her bladder cancer surgery. After one and a half years of follow-up, the mass was progressively enlarged, and was classified as Bosniak type III. After evaluating the anatomical structure around the lesion by 3D reconstruction computed tomography, she received cystoscopic right double J ureteral catheter placement combined with retroperitoneal laparoscopic partial nephrectomy of the right kidney. After a 3-month follow-up, no tumor recurrence was observed, with normal kidney function. Retroperitoneal laparoscopic NSS of horseshoe kidney with hemangioma is feasible and adequate preoperative 3D reconstruction imaging is the guarantee of safe and smooth operation.

[LAPAROSCOPIC LIVE DONOR NEPHRECTOMY WITH HORSESHOE KIDNEY: A CASE REPORT].

We performed laparoscopic live donor nephrectomy (LDN) on approximately 200 patients in Ehime Prefectural Center Hospital between 2003 and 2016. In 2016, a fifty-something woman who was a donor candidate for her husband was revealed to have a horseshoe kidney through contrast-enhanced computed tomography; other LDN procedures used a retroperitoneal approach, but this one used a transperitoneal approach since the latter approach allowed for a more favorable visual field. The left kidney was selected since renal scintigraphy showed equal bilateral renal function and renal arteries are simpler on the left side. The kidney was removed after the isthmus was successfully transected without ischemia. The opened calyx in the left kidney was sutured via bench surgery, and the kidney was transplanted to the recipient. Postoperative courses of both donor and recipient were good.

Percutaneous nephrolithotomy in horseshoe kidney: comparing ultrasound-guided access in flank position with conventional fluoroscopic-guided in prone position.

We conducted this study to compare radiation-free US-guided percutaneous nephrolithotomy (PNL) in the flank position with conventional PNL in the prone position for the treatment of renal stones in patients with horseshoe kidneys. In a retrospective study, 14 HSK patients that were treated with conventional fluoroscopy-guided PNL in the prone position (group A) were compared with twenty-four HSK patients that were treated US-guided PNL in the flank position (group B). Data on baseline characteristics, percentage of successful entries, stone-free rate, duration of admission and complication rate were obtained from data registry. The average duration of the operation was 57.6 min in group B, which was statistically less than group A with 65.9 min (P = 0.001). Access time varied from 10 to 32.4 min (mean = 17.1 min) in group A and 5-29.5 min (mean = 10.9 min) in group B (P < 0.001). Access length had a significant relation to the surgery method so PNL with US-guided had less access length (P = 0.002). There was no significant relationship between the surgery guide and the residual stone rate (P = 0.6). Hemoglobin decrease (P = 0.5), hospitalization duration (P = 0.5) and need for blood transfusion (P value = 0.6) were not statistically different between the two groups. PNL with US guidance in flank position is a safe and effective technique in HSK patients and is associated with fewer complications than the traditional approach as well as reduced operating time, radiation exposure, and its complications.

Case Report: Horseshoe Kidney Transplantation Using Split Technique.

With the increasing demand for donor organs and its limited availability, kidneys with atypical anatomy are being used more and more. The experience with transplanting horseshoe kidneys is limited. Understanding variations in uretero-pelvic anatomy and aberrant vascular anatomy is of paramount importance for the utilization of horse-shoe kidneys for transplantation. We describe our experience in procuring a horse-shoe kidney from a deceased donor, splitting the kidney and transplantation into 2 recipients.

Intraoperative indocyanine green fluorescence navigation in a robot-assisted partial nephrectomy for a large renal cell carcinoma in a horseshoe kidney.

A man in his 60s was referred to the urology department with an incidental finding of large 75 mm mass within a horseshoe kidney. CT imaging highlighted the well-known aberrant arterial anatomy seen in horseshoe kidney which often causes significant surgical challenges.After careful preoperative planning, the mass was resected successfully during a robot-assisted partial nephrectomy. Intraoperatively, indocyanine green fluorescence navigation helped to confirm arteries supplying area of resection were appropriately clamped, allowing for safe resection of the mass. Histology revealed a chromophobe renal cell carcinoma with clear margins. The patient was discharged on day 4 postoperatively and continues to be cancer free on routine surveillance imaging.

Horseshoe Kidney in a Patient with Leriche Syndrome.

Horseshoe kidney (HSK) is one of the most common congenital renal fusion anomalies. Difficulties are encountered during surgery of aortic diseases associated with this anomaly. A 47-year male presented to the Outpatient Clinic with one-year history of intermittent claudication in 20 meters. He was diagnosed with Leriche syndrome and horseshoe kidney (HSK). The patient underwent aorto-bifemoral bypass surgery via transperitoneal approach. The proximal anastomosis was completed in an end-to-side fashion. The bifurcated graft was positioned posteriorly to the isthmus; and distal anastomoses were performed onto the common femoral arteries. He was discharged from the hospital on the eighth postoperative day without any complications. Key Words: Abdominal aorta, Surgery, Horseshoe kidney, Leriche syndrome.

Pathologic Findings and Management of Renal Mass in Horseshoe Kidneys.

OBJECTIVES: To evaluate the management, surgical outcomes, and pathological findings in patients with tumor in a horseshoe-kidney (HK). HK patients present unique challenges due to aberrant vascular anatomy and risk of renal insufficiency. We hypothesized that many tumors in this setting may be indolent or benign. MATERIALS AND METHODS: Patients managed for renal mass in HK at our center (1999-2021) were reviewed. Baseline characteristics, surgical approach, complications, functional outcomes, pathology, and survival were analyzed. RESULTS: Forty-three procedures were performed in 42 patients with HK including 24 nephron-sparing surgeries (NSS) and 19 radical nephrectomies (RN: splitting the isthmus and saving the contralateral moiety). NSS included 22 partial nephrectomy (PN) and 2 thermal ablations. Median tumor size was 4.3 cm. Eighteen cases (42%) were minimally-invasive, 17 open-midline, and 8 other open approaches. Ninety-day Clavien III-V complication rate was 12% with no mortalities. For PN, median warm/cold ischemia times were 26/31 minutes, respectively. On pathology, only 27 tumors (63%) were renal-cell-carcinoma (RCC), and 22 tumors (51%) were either benign (n = 10) or low grade, confined RCC (n = 12). Preoperative/new baseline/long-term eGFR were 82/83/78 mL/min/1.73 m2 after NSS vs 75/48/57 mL/min/1.73 m2 after RN, respectively. Long-term dialysis was required in 3 patients (7%). Median follow-up was 36 months. Five-year recurrence-free survival was 83% for NSS and 66% for RN. CONCLUSIONS: Management of renal masses in HK is challenging and requires versatility with multiple surgical approaches. Preservation of renal function was accomplished in most patients, with a functional advantage observed for NSS. RCC was less common than expected while benign and non-aggressive tumors were prevalent, suggesting consideration for preoperative renal-mass-biopsy when feasible.