CT findings of the main pathological conditions associated with horseshoe kidneys

Particularities in the "Oldie but Goldie" Tc-99m DMSA Renography: A Retrospective Reference Centre Overview of 931 Children

Background/Objectives: The Tc-99m dimercaptosuccinic acid (DMSA) renal scan clearly images the renal cortex, highlighting functional tissue areas and indicating regions of renal scarring, infection, malformations, or other types of renal damage. To enhance the management of paediatric cases involving renal malformations and to reduce the incidence of chronic and progressive kidney diseases in "future adults", our study aims to identify and categorise various renal anomalies. Methods: This has been achieved by analysing the Tc-99m DMSA renal scans of a large cohort of 931 children diagnosed with different renal pathologies. After interpreting the scans, we categorised the renal malformations and cortical modifications into four groups: kidney number anomalies, positional anomalies, structural anomalies, and shape anomalies. Results: There has been a notable increase in the demand for renal scintigraphy in recent years, rising from 82 cases in 2019 to 183 cases in 2024. Structural anomalies were the most common type of malformations (73% from all patients), featuring a significant variety of cortical modifications. In total, 98 cases (93% from kidney number anomalies and 10.5% from all children) were diagnosed with renal agenesis. Additionally, 30 children (3.2% from all patients) had positional anomalies, primarily ectopic kidneys, and 54 patients (5.8% from all cases) had shape malformations, especially fused kidneys. Conclusions: Combining the Tc-99m DMSA renal scan with ultrasound provides a more reliable diagnosis of paediatric renal progressive diseases. A more accurate diagnosis allows for quicker treatment and prevention of potential complications, ultimately improving the quality of life and decreasing hospital costs of paediatric patients becoming adults.

Congenital Abnormalities of Kidneys and Urinary Tract: A Top--Down Review of the Embryology and Imaging Appearance

Congenital abnormalities of the kidneys and urinary tract (CAKUT) encompass a spectrum of pathology ranging in severity from incidental findings to marked deviations of anatomic form and function. The imaging appearance of CAKUT generally reflects a deviation from normal embryologic development. Common and uncommon congenital abnormalities of the kidneys, ureters, bladder, and urethra are reviewed with an emphasis on the imaging appearance and embryologic origin so that they may be promptly identified and treated when encountered in clinical practice.

Lower Limb Ischemia Caused by Aortic Atherosclerosis Localized in the Horseshoe Renal Isthmus

Intermittent claudication in patients with horseshoe kidneys may arise from sclerotic changes in the aorta due to compression by the renal isthmus. Vascular disease is a relatively lesser-known extrarenal complication of horseshoe kidneys, but it warrants attention.

Horseshoe kidney presenting with features of left ureteropelvic junction obstruction-insights into management: a case report and review of the literature

BACKGROUND

Horseshoe kidney is the most common renal fusion anomaly, occurring in approximately 1 in 500 individuals worldwide. It is characterized by abnormalities in kidney position, rotation, and vascular supply. While often asymptomatic, horseshoe kidneys can lead to urological complications, primarily due to ureteric obstruction and impaired urinary drainage.Although ureteropelvic junction obstruction (UPJO) is uncommon in horseshoe kidneys, its occurrence presents unique diagnostic and management challenges. This case explores the etiology, clinical presentation, and surgical management of UPJO in a patient with a horseshoe kidney, highlighting the critical role of urologists in addressing these anatomical and functional complexities.

CASE PRESENTATION

We report the case of a 3-month-old African male infant who presented with a two-month history of excessive crying and symmetrical abdominal distension. Radiological evaluation revealed a horseshoe kidney with decreased parenchymal thickness in the left kidney and marked hydronephrosis of the pelvis and calyces, with abrupt cessation at the left ureteropelvic junction. Surgical correction of the obstruction was performed successfully. The patient was followed for six months, during which he remained symptom-free with normal renal function tests.

CONCLUSION

Ureteropelvic junction obstruction in a horseshoe kidney presents unique anatomical challenges. Symptomatic cases require thorough imaging for diagnosis and surgical planning. Pyeloplasty is the typical surgical intervention, meticulously planned to address these complexities. This ensures effective relief of obstructions and proper urinary drainage.

Reviewing the complexities of horseshoe kidney: insights into embryogenesis and surgical considerations

Horseshoe kidney (HSK) is a common renal malformation with unique and complex characteristics. A systematic literature search was conducted using PubMed and ScienceDirect databases. Several theories have been proposed regarding HSK formation, such as the close apposition of the kidneys during ascent through an arterial fork, lateral flexion of the trunk, and caudal embryonic rotation. Emerging evidence from animal models implicates notochord signaling and the sonic hedgehog pathway in HSK formation. The isthmus, a defining feature of HSK, is hypothesized to arise from ectopic mesenchymal tissue. The surgical anatomy of HSK is complex, given the variability in location, orientation, and blood supply. Both arterial and venous anatomy exhibit significant variability, raising questions about whether anomalous blood supply is a cause or a consequence of abnormal renal position. The isthmus usually contains functional renal parenchyma and fusion between the kidneys, primarily at the lower pole. While it is often stated that the inferior mesenteric artery is "held back" at the L3 level, this anatomical configuration is present in only 40% of cases. The review highlights the need for further research and provides a comprehensive overview of HSK knowledge.

Can the inferior mesenteric artery cause ureteropelvic junction obstruction?

Ureteropelvic junction obstruction (UPJO) is a pathological condition characterized by obstruction of the junction between the renal pelvis and ureter, often resulting in dilatation of the renal collecting system. Aberrant accessory vessels or early branching of the inferior pole vessels are the most common causes of extrinsic UPJO. The inferior mesenteric artery has not been reported as a common cause of UPJO. Here, we report the case of a 7-year-old patient with UPJO and an anomalous inferior mesenteric artery. The patient was initially diagnosed with congenital uropathy during the evaluation for primary enuresis.

Situs Inversus, a Choledochal Cyst and a Horseshoe Kidney: A Strange Coincidence of Congenital Conditions

Situs inversus is a condition in which abdominal and thoracic organs are laterally transposed. The organs which are supposed to be on the right side of the abdomen are on the left and vice versa. It is a rare congenital condition; however, the exact incidence is difficult to determine as most of the cases go unnoticed until they undergo an imaging study.  We report a case of a 30-year-old female presenting with situs inversus in association with a choledochal cyst and a horseshoe kidney. She underwent imaging evaluation for non-specific abdominal pain. Her routine clinical examination revealed a soft abdomen without any tenderness. Routine laboratory tests were within normal limits. Since there was abdominal pain, ultrasonography of the whole abdomen was advised. It revealed the presence of abdominal organs on the opposite side as normally seen. The common bile duct was dilated, and lower poles of the kidneys were fused. The cardiac apex was found to be on the right. It was followed up with a computed tomography scan which confirmed situs inversus. The common bile duct was dilated without any obstructive pathology in the pancreatic head or periampullary region. Lower poles of the kidneys were found to be fused together in front of the retroperitoneal vessels through an isthmus. Based on these findings, a diagnosis of situs inversus in a case of a choledochal cyst and a horseshoe kidney was made. Situs inversus is a rare entity. Its association with choledochal cysts and horseshoe kidneys has never been reported in the literature to the best of our knowledge.

Single Branch Endovascular Aortic Repair Procedure for an Abdominal Aortic Aneurysm in a Patient With Horseshoe Kidney: A Case Report

Introduction

Horseshoe kidney (HK) is an anatomical variant characterised by abnormalities in the position, rotation, and vascular supply of the kidney, with functioning renal masses on both sides of the vertebral column fused together at the isthmus. Due to the altered pattern of kidney vasculature, endovascular aortic repair for aortic abdominal aneurysm (AAA) in the presence of HK requires vascular anatomy specific planning.

Report

A 68 year old male, with multiple comorbidities, presented with an asymptomatic AAA and HK. The kidney vasculature was characterised by the presence of three arteries: two arising laterally at the same level and a third polar artery arising from below. The polar artery was 6 mm in diameter and larger than the other two; therefore, in order to preserve this artery, a custom-made device with a single side branch was implanted below the main renal arteries. A balloon expandable covered stent was used to complete the side branch into the polar renal artery. The follow-up computed tomography angiography revealed a successful outcome, with total aneurysm exclusion, branched graft patency, no endoleak, and unchanged renal function.

Discussion

This case report shows a possible surgical solution for a case of HK with AAA and the importance of accurate endovascular planning. Large polar arteries, if present, need to be preserved, and custom-made devices in the modern endovascular era permit that. This approach could represent the best option for complicated patients.

Large renal lymphoma in a patient with horseshoe kidney: A case report

Horseshoe kidney (HSK) is the most common renal fusion anomaly. It frequently consists of kidney fusion in the lower pole across the midline and occurs during embryogenesis. The incidence of malignancies in HSKs can be 3-4 times higher than that in normal kidneys. A 69-year-old man with a voluminous right kidney neoplasm in HSK and a single omolateral axillary lymphadenopathy underwent complete excision of right axillary lymphadenopathy and ultrasound-guided percutaneous biopsy of the right kidney expansive lesion. The diagnosis of non-Hodgkin's B cell lymphoma both in HSK and right axilla was made. We report this case to raise awareness among physicians regarding the importance of a correct clinical evaluation and diagnostic workup so as to avoid surgery, which is not easy and without complications, in patients with this kidney anomaly. Primary renal lymphoma should also be included among possible neoplasms of HSK. Renal biopsy should always be recommended in cases where atypical findings are obtained from imaging techniques and when its outcome can impact clinical decision-making. In the present case, biopsy was performed, and thus, nephrectomy was avoided and specific medical therapy was quickly started.

An Unusual Case of Flank Pain Late in Life: A Case Report

Abnormalities in renal fusion represent a subset of congenital anomalies of the kidneys and urinary tract (CAKUT). Horseshoe kidneys (HSKs) are the fusion of kidneys at their lower poles. It is the most common form of CAKUT. Symptoms are usually subtle. The diagnosis is usually made incidentally during childhood. Rarely does an HSK become symptomatic later in life. We present the case of an 88-year-old female with a history of HSK who presented to the emergency department (ED) with a three-week history of left-sided flank pain, intermittent nausea, and reduced urine output. Her inpatient workup included imaging that revealed an HSK and bilateral hydronephrosis, which was more prominent on the left. The onset of symptoms for an HSK late in life is extremely rare.

Wilms Tumor in Child With Trisomy 18 and Horseshoe Kidney

Trisomy 18 is associated with several congenital malformations, including horseshoe kidney. It can be full, partial, or mosaic, and mosaicism is often associated with lesser severity and longer life expectancy, placing patients at greater risk of developing neoplasms or malignancies. One common tumor among children with Trisomy 18 is Wilms tumor, which is also associated with renal congenital abnormalities such as horseshoe kidney. We present a case describing the occurrence of these three characteristics: development of Wilms tumor in a patient with Trisomy 18 and a horseshoe kidney and discuss treatment with regards to these conditions.

Horseshoe kidney: Morphologic features, embryologic and genetic etiologies, and surgical implications

The horseshoe kidney (HSK) is the most common congenital abnormality of the upper urinary tract with an incidence of approximately 1 in 500 in the general population. Although individuals with HSK are often asymptomatic, they are at increased risk for neoplasms, infections, ureteropelvic obstruction secondary to lithiasis or vascular compression. Direct injury from trauma is increased in these individuals as is the risk of intraoperative complications secondary to damage involving the typically complex renal or adrenal vascular supply. We briefly review etiological factors including renal and urinary system embryology, genetic mutations, abnormalities related to faulty cell signaling, aberrant cell migration, and other possible causes including environmental exposures and trauma. In addition, we call attention to factors that might influence the success of surgical procedures in patients with HSK. We argue that an understanding of possible etiologies of the HSK and its different subtypes may be useful when planning surgical procedures or considering risk-benefit ratios associated with different surgical options. We briefly present the organization of a HSK in a 100-year-old male demonstrating an unusual vascular supply discovered during a dissection laboratory session in a medical school anatomy course. We describe the structure of the HSK, the position and relationships of the HSK to other structures within the abdomen, and the associated vascular relationships.

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.

Prevention of ureteral injury during laparoscopic colorectal cancer surgery with horseshoe kidney using fluorescent ureteral catheters: a case report

BACKGROUND

Horseshoe kidney is one of the most common congenital renal fusion anomalies and is characterized by abnormalities in the position, rotation, vascular supply, and ureteral anatomy of the kidney. When performing surgery for colorectal cancer in patients with horseshoe kidneys, anatomical identification is important to avoid organ injuries. Several reports on surgery for colorectal cancer with horseshoe kidneys have described the usefulness of three-dimensional (3D) computed tomography (CT) angiography for detecting abnormalities in vascular supply. However, few reports have focused on the prevention of ureteral injury in surgery for colorectal cancer with horseshoe kidney, despite abnormalities in the ureteral anatomy. Here, we report a case in which laparoscopic sigmoid colon resection for sigmoid colon cancer with a horseshoe kidney was safely performed using fluorescent ureteral catheters.

CASE PRESENTATION

A 60-year-old Japanese man presented to our hospital testing positive for fecal occult blood. Colonoscopy revealed sigmoid colon cancer, and CT confirmed a horseshoe kidney. The 3D-CT angiography showed aberrant renal arteries from the aorta and right common iliac artery, and the left ureter passed across the front of the renal isthmus. A fluorescent ureteral catheter was placed in the left ureter before the surgery to prevent ureteral injury. Laparoscopic sigmoid colon resection with D3 lymph node dissection was performed. The fluorescent ureteral catheter enabled the identification of the left ureter that passed across the front of the renal isthmus and the safe mobilization of the descending and sigmoid colon from the retroperitoneum. The operative time was 214 min, with intraoperative bleeding of 25 mL. The patient's postoperative course was good: no complications arose and she was discharged on the seventh postoperative day.

CONCLUSION

In patients with horseshoe kidney, the use of fluorescent ureteral catheters and 3D-CT angiography enables safer laparoscopic surgery for colorectal cancer. We recommend the placement of fluorescent ureteral catheters in such surgeries to prevent ureteral injury.

Non-papillary prone percutaneous nephrolithotomy for renal abnormalities: single-institution experience

PURPOSE

To evaluate the effectiveness and safety of non-papillary prone PCNL for the treatment of patients with renal abnormalities.

METHODS

An observational retrospective cohort study including PCNL cases of patients with renal abnormalities was performed. The following inclusion criteria were applied: renal stones > 1.5 cm with maximal diameter, anatomical malformations of affected kidney (malrotated kidneys, horseshoe kidneys and kidneys with complete duplicated systems, medullary sponge kidney), patients treated with standard (30Fr) PCNL or mini-PCNL (22Fr). The lithotripsy was performed using the Lithoclast Master or the Lithoclast^® Trilogy (EMS Medical, Nyon, Switzerland).

RESULTS

Overall, 57 patients, 35 males, and 22 females with any renal malformation underwent non-papillary prone PCNL. Our study included 25 patients with horseshoe kidneys, 21 with malrotated kidneys, 9 with kidneys with duplicated pelvicalyceal systems and 2 with medullary sponge kidneys. The mean cumulative stone size was 36 ± 1.4 mm and most of the stones were in the lower calyceal group (36.9%) and in the pelvis (27.2%). The stone-free rate (SFR) was 84.2% and the mean hospitalization time was 2.7 ± 0.7 days. In total, postoperative complications were developed in six patients (10.5%), half of them presenting fever and the other half requiring blood transfusion (Grade II).

CONCLUSION

The PCNL is the method of choice for treating large stones in anomalous kidneys. The generally accepted panacea that only a papillary puncture is safe is questioned by our results. Based on our experience, a non-papillary puncture proved to be a safe and effective procedure.

Optimal patient position for percutaneous nephrolithotomy in horseshoe kidneys: Traditional prone or supine?

OBJECTIVE

Although it was stated that supine percutaneous nephrolithotomy (PCNL) was associated with relatively shorter surgical times and comparable success and complication rates, there is no consensus in the current literature concerning the safety and efficacy of supine PCNL in patients with horseshoe kidneys. We aimed to compare supine and prone PCNL regarding safety and efficacy in patients with horseshoe kidneys.

METHODS

Data of the patients with horseshoe kidneys who underwent PCNL for renal stones larger than 2 cm between January 2010 and May 2021 were retrospectively reviewed. The study patients were categorized as Group 1 (i.e., supine PCNL-SPCNL) and Group 2 (i.e., prone PCNL-PPCNL). Both groups were compared regarding demographic, clinical, and surgical data.

RESULTS

Sixty-five patients were included. Among these patients, 31 (47.7%) were in Group 1, while 34 (52.3%) were in Group 2. Both groups were statistically similar in terms of demographic data, stone characteristics, perioperative parameters, and complication rates (p > 0.05). There was no statistical difference in terms of additional treatment rates, stone-free rates in the postoperative second-day and third-month evaluations (p > 0.05). Mean surgical time was significantly longer in Group 2 (113 ± 17.1 min) than in Group 1 (90.6 ± 11.3 min) (p = 0.000).

CONCLUSION

Although it is traditionally performed in the prone position, the supine approach is as safe and effective as the prone approach. In addition, the supine approach is associated with significantly shorter surgical times.

Pure laparoscopic radical nephroureterectomy for complicated renal pelvis carcinoma combined with horseshoe kidney: A case report and literature review

We reported a case of pure laparoscopic radical nephroureterectomy for complicated renal pelvis carcinoma combined with horseshoe kidney (HSK). The aim was to present a case report and review of the literature about renal pelvis carcinoma combined with HSK. The case report includes a history of patient data. The pure laparoscopic radical nephroureterectomy was provided with the informed consent of the patient. A 53-year-old patient was diagnosed with a right renal pelvis mass with HSK. We performed laparoscopic radical nephroureterectomy with partial cystectomy and horseshoe renal isthmus amputation. Histopathological features, computed tomography urography (CTU), and angiography (CTA) confirmed the diagnosis of renal pelvis carcinoma combined with HSK. The tumor was removed, and the patient had an uneventful recovery. Renal pelvis carcinoma combined with HSK is a rare case. Due to severe anatomical abnormalities, this disease is a major challenge for urologists. We share our successful case for readers to learn from.

Laparoscopic Nephroureterectomy with Heminephrectomy for Urothelial Carcinoma of the Upper Renal Pelvis on the Left Side of the Horseshoe Kidney

A 70-year-old male was diagnosed with urothelial carcinoma of the upper renal pelvis on the left side of the horseshoe kidney. Preoperative thin-slice contrast-enhanced CT with three-dimensional reconstruction of the images revealed that two arteries arising from the aorta supplied the left moiety of the horseshoe kidney. He underwent laparoscopic transperitoneal nephroureterectomy with heminephrectomy on the left side of the horseshoe kidney visualized by indocyanine green fluorescence system. The histopathological findings of the renal pelvic tumor revealed invasive urothelial carcinoma with squamous differentiation, high grade, and pT3.

Robotic nephroureterectomy in a horseshoe kidney for upper tract urothelial carcinoma

Upper tract urothelial carcinoma represents a small proportion (5%-10%) of all urothelial cancers. Although there are several management options, in undifferentiated or high-risk cases, surgery in the form of nephroureterectomy is the gold standard. Horseshoe kidney is the most common congenital renal fusion anomaly affecting 1 in 400-600 patients. We present the case of a smoker in her mid-50s with an incidental finding of a papillary lesion in the right renal pelvis of her horseshoe kidney on CT scan. She went on to have endoscopic assessment confirming no other foci of disease. She was definitively managed with a robotic nephroureterectomy.

Horseshoe kidney leading to ERCP failure; innovative use of guide wire during laparoscopic CBD exploration: A case report

INTRODUCTION

Horseshoe kidneys are the most common fusion defect of the kidneys, which amounts to about 0.25% of the population. They are usually asymptomatic and are often identified incidentally. The horseshoe kidney can push the second and third part of the duodenum anteriorly, leading to an altered CBD course. Choledocholithiasis is seen in approximately 10-15% of patients with cholelithiasis. Presently, the most preferred approach for managing CBD stones is ERCP. However, in ERCP failure cases, Laparoscopic CBD exploration is the primary treatment modality, with or without T-tube use, with all the advantages of minimally invasive surgery.

CASE PRESENTATION AND DISCUSSION

A 65-year-old female presented with complaints of pain in the right hypochondriac region for three months associated with nausea, jaundice, and loss of appetite and weight. Her USG abdomen showed cholelithiasis with dilated CBD with horseshoe kidney with severe hydronephrosis of the left kidney. They are usually asymptomatic and are often identified incidentally. In this patient, it was believed that the horseshoe kidney had pushed the second and third part of the duodenum anteriorly, leading to an altered CBD course leading to ERCP failure. MRCP confirmed cholelithiasis with choledocholithiasis with dilated CBD of 11.3 mm with horseshoe kidney. ERCP was attempted but was unsuccessful due to non-visualization of the papilla due to overcrowding of duodenal folds. For patients with ERCP failure, laparoscopic CBD exploration is mandatory. For this patient, the CBD was cannulated with a guidewire, if needed, for repeat ERCP and was closed with T-tube in situ.

CONCLUSION

There are no particular preoperative indicators that can predict the failure of ERCP. However, in ERCP failure cases, laparoscopic CBD exploration (with or without T-tube use) is the primary treatment modality.

Congenital Anomalies of the Upper Urinary Tract: A Comprehensive Review

The upper urinary tract is the most common human system affected by congenital anomalies. Congenital anomalies of the kidneys and ureters comprise a wide spectrum of disorders ranging from simple variants with no clinical significance to complex anomalies that may lead to severe complications and end-stage renal disease. They may be classified as anomalies of renal form, which are subclassified as structural anomalies (eg, persistent fetal lobulation, hypertrophied column of Bertin, and dromedary hump) and fusion anomalies (eg, horseshoe kidney and pancake kidney); anomalies of renal position (eg, renal malrotation, simple renal ectopia, and crossed renal ectopia) and renal number (eg, renal agenesis and supernumerary kidney); and abnormalities in development of the urinary collecting system (eg, pyelocaliceal diverticulum, megacalycosis, ureteropelvic junction obstruction, duplex collecting system, megaureter, ectopic ureter, and ureterocele). US is usually the first imaging modality used because of its low cost, wide availability, and absence of ionizing radiation. Intravenous urography and voiding cystourethrography are also useful, mainly for characterization of the collecting system and vesicoureteral reflux. However, intravenous urography has been replaced by CT urography and MR urography. These imaging methods not only allow direct visualization of the collecting system but also demonstrate the function of the kidneys, the vascular anatomy, adjacent structures, and complications. Comprehension of congenital anomalies of the upper urinary tract is crucial for an accurate diagnosis and correct management. The authors discuss the spectrum of these anomalies, with emphasis on embryologic development, imaging findings, clinical manifestations, and complications. Online supplemental material is available for this article. ^©RSNA, 2021.

Laparoscopic resection for low rectal cancer in a patient with horseshoe kidney - Technical considerations to prevent iatrogenic injuries

Horseshoe kidney (HSK) is a rare congenital malformation of the kidneys and is commonly associated with other anomalies of the renovascular and ureteropelvic systems. These anomalies present a surgical challenge, especially for surgeries involving the retroperitoneum. We present the case of a 56-year-old male patient with biopsy-proven rectal cancer who had completed neoadjuvant chemoradiation and was planned for curative resection. Contrast-enhanced computed tomography (CECT) of the abdomen and pelvis revealed the presence of an HSK. Reconstructed three-dimensional (3D) images of the renal vasculature revealed the presence of an accessory renal artery originating directly from the aorta and supplying the isthmus of the HSK without any other venous or ureteral anomalies. Laparoscopic abdominoperineal resection with total mesorectal excision was done without any untoward complications. The presence of HSK per se is not a contraindication for laparoscopic operations involving the retroperitoneum. Pre-operative 3D CECT helps to identify the presence of anatomical variations and guides surgical resection.

Laparoscopy combining with ureteroscopy for horseshoe kidney accompanying with duplicate kidney and a ureteral calculus: a case report

BACKGROUND

Horseshoe kidney (HSK) is a common renal fusion anomaly, occurring in about 1 in 400-600 individuals. In addition, the incidence of duplicated collecting system is about 0.8%.

CASE PRESENTATION

This report documents an extremely rare case, which was treated by multiple procedures in the same operative session to accomplish laparoscopic amputation of the HSK isthmus, resection of duplicate kidney and ureteroscopic lithotripsy.

CONCLUSION

Results showed that minimally invasive surgery with use of multiple endoscopes may be a feasible choice for this patient population with complicated comorbid renal conditions.

Primary desmoplastic small-round-cell tumor of the ovary

BACKGROUND

Desmoplastic small-round-cell tumor (DSRCT) is an extremely rare and highly aggressive malignancy. It is of yet unclear origin, but it is assumed to be of a mesothelial origin based on its tendency for widespread metastasis in serosal linings.

CASE PRESENTATION

In this report, we describe a young female who presented with bilateral ovarian masses that mimicked the classic clinical picture of ovarian cancer. The patient had a cytoreductive surgery done in the form of total abdominal hysterectomy, bilateral salpingo-oophorectomy, omentectomy, pelvic peritonectomy, low para-aortic and bilateral iliac lymphadenectomy. Postoperative course was smooth with no adverse events. The final pathology report revealed desmoplastic small-round-cell tumor. Afterwards, the patient was referred to medical oncologist to receive her adjuvant therapy.

CONCLUSIONS

DSRCT is still an unknown disease to us given the limited number of cases and poor survival. Given the lack of clear guidelines, treatment is offered based on the best available evidence and the collaborative effort of a multi-disciplinary team.

Pancake kidney, a rare and often misdiagnosed malformation: a case report and radiological differential diagnosis

Renal ectopia and fusion anomalies are Congenital Anomalies of the Kidney and the Urinary Tract (CAKUT) that are usually incidentally detected and asymptomatic. Patients affected present a higher risk of complications like recurrent urinary tract infections or obstruction. Pancake kidney (PK) is one of the rarest types of renal anomaly with complete fusion of the superior, mild and inferior poles of both kidneys in the pelvic cavity. Each kidney has its own excretory system with two ureters that do not cross the midline. In the asymptomatic cases, a conservative approach should be performed. Surgical management may be needed when urological problems occur. PK is often associated with congenital anomalies of other organs. Ultrasound is the first line radiological examination for the diagnosis and the follow-up of kidney malformations. The main sonographic findings suggesting PK diagnosis are a large and lobulated renal mass consisting of two fused lateral lobes without an intervening septum located in the pelvic cavity. Each lobe usually has a separate pelvicalyceal system, the renal pelvis is anteriorly placed and the ureters are usually short and enter the bladder normally without crosses the midline. Ultrasonography gives useful information on the morphology and volume of the organ, and on its vascularization through the use of the Color- and Power-Doppler. Computer Tomography and Magnetic Resonance Urography are second level techniques used to confirm the diagnosis and to evaluate the presence of other abnormalities. The knowledge of the imaging findings and the anatomy of congenital renal malformations is important to avoid diagnostic pitfalls and misinterpretations. We report the case of a 14-years old female with PK who was misdiagnosed with a horseshoe kidney (HSK) during an abdominal ultrasound.

A deadly trap for para-aortic lymph node dissection in patients with horseshoe kidney as a complication: a case report

Horseshoe kidney is a rare congenital renal dysplasia. It is often associated with various anatomical abnormalities, including renal vessel and ureter variability, which increase unpredictable surgical risks. This current report describes the case of a 42-year-old woman diagnosed as having cervical squamous cell carcinoma complicated by horseshoe kidney. She underwent laparoscopic radical hysterectomy, bilateral oophorectomy and lymph node dissection, including dissection of the pelvic, presacral and para-aortic lymph nodes. The surgery was challenging, but no serious complications occurred. Postoperative multi-slice computed tomography angiography confirmed the anatomical variation of the renal location, ureter and renal vessels. To our knowledge, this is the first reported case of cervical carcinoma complicated with horseshoe kidney.

Establish new formulas for the calculation of renal and isthmus depth in horseshoe kidney

This study was performed to develop a new formula to estimate the renal and isthmus depth in horseshoe kidney, and to compare the new formula with previously published formulas.Renal depth, isthmus depth, vertebral thickness, and total thickness (T, cm) of the body at the level of the kidneys were measured by CT in 124 adults. Their sex, age, height (H, cm), and weight (W, kg) were recorded. Multiple stepwise linear regression analysis was conducted. The 124 cases were divided into 2 random groups, of which the first group was used to derive a regressive formula and the second group was used to verify the formula and compare the formula with previously published formulas.Multiple stepwise linear regression analysis showed that the important variables in estimating the depth of each kidney were the body weight (W, kg) and the total thickness (T, cm) of the body at the level of the kidneys. The important variables in estimating the depth of isthmus soft tissue and vertebral thickness were W, T, and age, W. The new formula was the following: right renal depth (cm) = 0.273 × T + 0.043 × W + 1.086 (r = 0.82, P < .05; standardized regressive coefficient: T = 0.500, W = 0.367), left renal depth (cm) = 0.245 × T + 0.041 × W + 0.676 (r = 0.83, P < .05; standardized regressive coefficient: T = 0.520, W = 0.353); isthmus depth (cm) = soft tissue depth + vertebral thickness, soft tissue depth (cm) = 0.144 × T + 0.044 × W + 0.536 (r = 0.58, P < .05; standardized regressive coefficient: T = 0.272, W = 0.335), vertebral thickness (cm) = 0.012 × age + 0.018 × W + 3.683 (r = 0.53, P < .05; standardized regressive coefficient: age = 0.326, W = 0.438). It is much better than the literatures.The new renal depth estimation formula in horseshoe kidney that we derived by using multiple stepwise linear regression has greatly outperformed other 6 previously published formulas. Isthmus depth estimation formula can also get accurate results. Our new formula provides a more reliable and accurate renal and isthmus depth estimation and contributes to improving the methods used to estimate renal function from radionuclide renography in horseshoe kidney.

3D CT of renal pathology: initial experience with cinematic rendering

3D computed tomography (CT) visualizations of volumetric data have become an important aspect of diagnostic imaging. The utility of 3D CT has been well described for the imaging of a number of renal pathologies. Recently, a new 3D visualization technique known as cinematic rendering (CR) has become available and provides photorealistic images derived from standard CT acquisitions by use of a complex global lighting model. Herein, we describe a number of normal variant and pathologic conditions of the kidney visualized with CR. We provide comparisons of findings with CR to traditional methods of 3D imaging and comment on the potential applications of this new method of 3D CT rendering.

Incidence and characteristics of kidney stones in patients with horseshoe kidney: A systematic review and meta-analysis

Introduction

The horseshoe kidney (HSK) is the most common type of renal fusion anomaly. The incidence and characteristics of kidney stones in patients with HSK are not well studied. The aim of this meta-analysis was to evaluate the incidence and types of kidney stones in patients with HSK.

Methods

A systematic literature search was performed using MEDLINE, EMBASE, and Cochrane Database of Systematic Reviews from the databases' inception through November 2016. Studies assessing the incidence and types of kidney stones in patients with HSK were included. We applied a random-effects model to estimate the incidence of kidney stones. The study protocol was registered with PROSPERO (International Prospective Register of Systematic Reviews; no. CRD42016052037).

Results

A total of 14 observational studies with 943 patients (522 adults and 421 pediatric) with HSK were enrolled. The estimated pooled incidence of kidney stones was 36% (95% confidence interval [CI], 15%-59%) in adults with the HSK. Kidney stones were less common in pediatric patients with HSK with an estimated pooled incidence of 3% (95% CI, 2%-5%). The mean age of adult stone formers with HSK was 44.9 ± 6.2 years, and 75% were males. Within reported studies, 89.2% of kidney stones were calcium-based stones (64.2% calcium oxalate [CaOx], 18.8% calcium phosphate [CaP], and 6.2% mixed CaOx/CaP), followed by struvite stones (4.2%), uric acid stones (3.8%), and others (2.8%).

Conclusions

Kidney stones are very common in adult patients with HSK with an estimated incidence of 36%. Calcium-based stones are the most prevalent kidney stones in adults with HSKs. These findings may impact the prevention and clinical management of kidney stones in patients with HSK.

Challenging case of horseshoe kidney double fracture

INTRODUCTION

Renal injuries occur in 10% of blunt abdominal traumas, 7% of these occur in kidneys with congenital or acquired disorders. Trauma of horseshoe kidney is an uncommon finding.

PRESENTATION OF A CASE

We present the case of 31 year-old caucasian man with no remarkable personal records, who was brought to our Trauma Unit soon after being involved in a motorcycle collision. A Contrast Enhanced - Multi Detector Computed Tomography (ce-MDCT) revealed a double disconnection of a horseshoe kidney. The patient was not aware of bearing such abnormality.

DISCUSSION

Trauma of horseshoe kidney is an uncommon finding. The abdominal ce-MDCT scan is the diagnostic tool of choice since the renal anatomy, injury grading and vascular or urinary tract abnormalities are well depicted and easily identified. The conservative management of these injuries is associated with a lower rate of nephrectomies and kidney failure while selective trans-catheter renal embolization is a challenging treatment option. However surgery can be a treatment of choice and should be aimed to preserve renal function.

CONCLUSION

the interest in our case lies in the rarity and particular anatomical aspect of such injuries and the implication related to its management in an emergency setting.

Minimal change disease in horseshoe kidney

The horseshoe kidney is a frequent urological birth defect. The most frequent complications are urinary tract infections, stones and hydronephrosis. The occurrence of glomerular disease in horseshoe kidney is rare. Therefore, we report the first case of minimal change disease occurring in a patient with horseshoe kidney in literature. A 22-year-old Caucasian man without personal or family medical history admitted to the pneumology department for a pulmonary artery embolism. In presence of a generalized oedema, a biological assessment was performed yielding intense nephrotic syndrome with urine protein excretion 22g/day. The abdominal ultrasound revealed a horseshoe kidney. Hence a scanno-guided kidney biopsy was taken yielding minimal change disease. High dose steroids were started, then gradually tapered with good response. Horseshoe kidney is the most common renal fusion anomaly, with a prevalence of 0.25% among the general population. The occurrence of glomerular nephropathy in horseshoe kidney has been reported in few cases. We report the first case of minimal change disease occurring in a patient with horseshoe kidney in literature. The mechanism of the association between the horseshoe kidney and these renal pathologies could not be explained in the previous reports. There is no literature data indicating a high rate of glomerulonephritis in horseshoe kidneys. The co-incidence of two renal diseases in this patient can be only a coincidence. The question that arises is whether this glomerulopathy is associated or not with this anatomical abnormality. Further studies are needed to answer this question.

Renal trauma

The kidney is the most commonly injured genitourinary organ, and renal involvement has been reported in 1–5% of all trauma cases. Two mechanisms of renal injury are described, namely blunt (direct blow to the kidney, rapid acceleration/deceleration or a combination) and penetrating (from stab or gunshot wounds), with blunt injuries being most common in the UK. It is important to keep an index of suspicion for renal trauma as given by the mechanism of the injury or in poly-trauma. Accurate assessment and resuscitation are vital in the initial management. Imaging with computed tomography is critical to the accurate grading of the injury and helps guide subsequent treatment. The approach to management of renal injuries has changed over time. During the past two decades, advances in cross-sectional imaging coupled with minimally invasive intervention strategies (like angiography, embolisation and ureteric stenting) for managing traumatic renal injuries have allowed increased renal preservation by reducing the need for major surgical intervention. Nowadays, the vast majority of blunt injuries (up to 95%) are managed conservatively with accumulated experience suggesting this is safe. However, there is still a role for open surgical exploration in patients with haemodynamic instability or those who fail initial conservative/minimally invasive management.

PERTINENT DRY NEEDLING CONSIDERATIONS FOR MINIMIZING ADVERSE EFFECTS - PART TWO

BACKGROUND

Dry needling (DN) is an evidence based treatment technique that is accepted and used by physical therapists in the United States. This clinical commentary is the second in a two-part series outlining some of the pertinent anatomy and other issues that are needed for optimal utilization of this treatment modality. Part one was an overview of the thorax with a summary of reported adverse effects (AEs) and the underlying anatomy that could be used to minimize patient risk. As is the case with any intervention, the technique of dry needling has some inherent patient risk. The incidence of AEs with this procedure is typically low, ranging from zero to approximately 10 percent. Knowledge of the underlying anatomy can be a key factor associated with decreasing the likelihood of an AE.

PURPOSE/OBJECTIVE

The second part of this clinical commentary goes beyond the thorax, to explore the anatomy associated with dry needling the abdomen, pelvis, and back. In the abdomen, pelvis and back, dry needling can penetrate the peritoneal cavity or adjacent organs, resulting in AEs. A physiological reaction that is an AE secondary to a needle insertion, pain or fear, is an autonomic vasovagal response. Additionally, suggestions for dealing with the fearful patient, the obese patient, universal precautions, and other clinical considerations, are discussed. The purpose of parts one and part two of this clinical commentary is to minimize the risk of a dry needling AE.

CONCLUSIONS/IMPLICATIONS

Dry needling is an effective adjunctive treatment procedure that is within the recognized scope of practice of the physical therapist. An evidence-based implementation of the procedure must be based on a thorough understanding of the underlying anatomy and the potential risks, with risks communicated to patients via informed consent.

LEVEL OF EVIDENCE

Level 5.

Glomerular filtration rate measured by (99m) Tc-DTPA renal dynamic imaging is significantly lower than that estimated by the CKD-EPI equation in horseshoe kidney patients

AIM

Gate's glomerular filtration rate (gGFR) measured by (99m) Tc-DTPA renal dynamic imaging and estimated GFR (eGFR) estimated by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation are two indexes used to evaluate renal function. However, little is known about whether gGFR can be used to accurately assess renal function in horseshoe kidney (HSK) patients with renal fusion anomalies.

METHODS

Nineteen HSK patients (HSK group) diagnosed by renal imaging and 38 CKD patients with "normal kidney shape" (non-HSK group) matched to the HSK patients in terms of gender, age and biochemical indicators at Chinese PLA General Hospital were enrolled in this study. Gender, age, serum total protein (TP), albumin (ALB), blood urea nitrogen (BUN), serum creatinine (Scr), gGFR and eGFR were recorded and analyzed using χ(2) test, t-test, and Wilcoxon test which was presented as median(IQR).

RESULTS

(1) There were no significant differences in gender, age, TP, ALB, BUN, Scr, or eGFR between these two groups. (2) In HSK patients, the renogram showed abnormal renal axis with the lower poles orientated medially. The timed uptake curve showed that the isotope excretion in the HSK group was slower than that in the non-HSK group. (3) For all HSK patients, gGFR was significantly lower than eGFR (range -12.52 mL/min per 1.73m(2) to -93.18 mL/min per 1.73m(2) ). There was no significant difference in eGFR between the HSK [96.42 (36.02) mL/min per 1.73 m(2) ] and non-HSK groups [94.46 (33.00) mL/min per 1.73 m(2) ]. The gGFR of the HSK group [41.18 (16.60) mL/min per 1.73m(2) ] was much lower than that of the non-HSK group [86.42(26.40) mL/min per 1.73m(2) , P < 0.001] and the eGFR of the HSK group (P < 0.001). The gGFR and eGFR of the non-HSK group were not significantly different.

CONCLUSION

gGFR measured by (99m) Tc-DTPA renal dynamic imaging is significantly lower than eGFR estimated by the CKD-EPI equation, which indicates that isotope renogram cannot accurately evaluate the GFR of HSK patients.