Partial unilateral ureteral obstruction in rats

This review comprises an overview of the current knowledge on experimental partial unilateral ureteral obstruction (PUUO) and a summary of our latest original experimental PUUO studies in rats. Neonatal PUUO is the type of obstruction that is most often encountered in pediatric clinical practice. However, the pathogenesis of PUUO is still incompletely understood. Most of our knowledge on PUUO has been derived from experimental studies in a variety of animal models. Although progress has been made, the natural history of congenital hydronephrosis is still incompletely described. The effects on kidney functions of long-term urinary tract obstruction, especially PUUO, have been less intensively studied. Recently, we created models with mild and severe PUUO in young rats by embedding the upper one fourth or the upper two thirds of the left ureter into the psoas muscle, respectively. Thereafter, the technique was used to create mild and severe PUUO in newborn rats and magnetic resonance imaging studies showed that both mild and severe obstruction caused a time-dependent decrease in renal blood flow. Compensatory increase in total kidney volume and renal vein blood flow in contralateral non-obstructed kidneys was not detectable when functional deterioration in the partially obstructed kidneys was present. Finally, we investigated the dynamic changes in renal relative signal intensity (RSI) of gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) using magnetic resonance imaging in rats with partial, complete unilateral ureteral obstruction and sham-operated controls. The results showed that changes in Gd-DTPA RSI are compatible with the known physiological and anatomical changes in kidneys in response to ureteral obstruction and useful for distinguishing an obstructed from a non-obstructed collecting system and also for differentiating a partially obstructed from a completely obstructed collecting system.     

Postoperative ureteral obstruction after confirmed ureteral patency: a case report

Ureteral injury after pelvic floor surgery and anti-incontinence surgery is a well-known risk [1, 2, 3]. It is common practice to evaluate ureteral patency immediately after surgery prior to leaving the operating theater to assure that the ureters are open and functional [1, 2]. In this report we discuss the case of a patient who was admitted 9 days after surgery with acute onset of ureteral obstruction after having patent ureters documented at the time of surgery. A literature search failed to show any documented cases.Abbreviations UTI Urinary tract infection     

Unilateral ureteral obstruction: beyond obstruction

Unilateral ureteral obstruction is a popular experimental model of renal injury. However, the study of the kidney response to urinary tract obstruction is only one of several advantages of this model. Unilateral ureteral obstruction causes subacute renal injury characterized by tubular cell injury, interstitial inflammation and fibrosis. For this reason, it serves as a model both of irreversible acute kidney injury and of events taking place during human chronic kidney disease. Being a unilateral disease, it is not useful to study changes in global kidney function, but has the advantage of a low mortality and the availability of an internal control (the non-obstructed kidney). Experimental unilateral ureteral obstruction has illustrated the molecular mechanisms of apoptosis, inflammation and fibrosis, all three key processes in kidney injury of any cause, thus providing information beyond obstruction. Recently this model has supported key concepts on the role in kidney fibrosis of epithelial–mesenchymal transition, tubular epithelial cell G2/M arrest, the anti-aging hormone Klotho and renal innervation. We now review the experimental model and its contribution to identifying novel therapeutic targets in kidney injury and fibrosis, independently of the noxa.     

Bilateral ureteral obstruction as a complication to a perforated appendix. Report of a case

A 44-year-old man developed anuria 8 days after an operation for a perforated appendix. An intravenous pyelography showed delayed excretion on both sides with hydronephrosis, a right dilated ureter and no contrast passing to the bladder. On neither sides a ureter-catheter could be passed through the obstructions from below. By surgical intervention no ureter-catheter could be passed through the obstructions from above, and both ureters were drained with a T-tube. The benign obstruction was caused by a periappendicular abscess with inflammation and oedema of the ureteral and periureteral tissues. The condition was normalized within 7 days.     

Prosthetic valve malfunction masked by intraoperative pressure measurements

IMPLICATIONS: We describe a case in which intraoperative echocardiography recorded an abnormally high pressure gradient across a newly implanted mechanical heart valve. However, inserting pressure-transducing needles on each side of this prosthesis did not confirm the echocardiographic findings. The prosthesis was later confirmed to be malfunctioning and was replaced.     

A case of paraureteral neurilemmoma causing ureteral obstruction: report of a case

Retroperitoneal neurilemmomas are rare tumors. They are usually asymptomatic, and often become quite large before they are discovered. A case is reported of a 75-year-old man with complaints of general malaise and left lumbar pain. Intravenous pyelography showed left renal nonfunctional and retrograde pyelography revealed the stenosis of the left ureter. The ultrasonogram demonstrated a cystic mass, and it was diagnosed as a retroperitoneal tumor with central necrosis by computerized tomography and magnetic resonance imaging. The tumor was removed with the left nonfunctioning kidney and ureter. The tumor was 3 x 3 x 4 cm, and the histological diagnosis was neurilemmoma (Antoni A + B type). There was a tight fibrous adhesion between the tumor and the left ureter, and the tumor was concluded to have originated from the adventitia of ureter. To date, 120 benign cases have been reported in Japan. They are reviewed and discussed.     

Intestinal obstruction caused by splenic volvulus: Report of a case

Torsion of a wandering spleen is rare, usually presenting as acute abdomen, and is commonly misdiagnosed. In special cases, ultrasonography, arteriography, and additional scintigraphy are extremely valuable in the preoperative diagnostic management. We herein present an unusual case of torsion of a wandering spleen in a 19-year-old female. The presenting symptom was acute gastrointestinal obstruction due to pressure of the enlarged and ptotic spleen in the pelvis. The intestinal obstruction with signs of peritonitis made a laparatomy with removal of the infarcted spleen imperative. After the operation, the patient made a complete recovery.     

Bilateral ureteral obstruction by periarterial fibrotic reactions in aortoiliac arteriosclerosis: report of a case

A 60-year-old man visited our hospital with the chief complaint of right flank pain. A right ureteral stone was suspected by the findings of KUB and DIP, and conservative treatment was carried out. Repeat KUB and DIP a month after treatment showed that the stone shadow was not visible and right hydronephrosis had increased. Closer examinations by RP and CT scan revealed right ureteral obstruction caused by periarterial fibrosis accompanied with arteriosclerotic changes of the aortoiliac region. The arteriosclerotic changes were confirmed by pelvic arteriography, and then right ureterolysis and lateral displacement were performed. DIP four months after the operation showed improvement of right hydronephrosis, but left hydronephrosis was observed. As the same cause as the right side was suspected, left ureterolysis and intraperitoneal transposition were also performed. Histological findings of each periureteral tissue resembled idiopathic retroperitoneal fibrosis. DIP three months after the second operation showed no hydronephrosis. Case reports of ureteral obstruction due to perianeurysmal fibrosis have not been infrequent recently, but our case showed severe arteriosclerotic changes instead of conspicuous aneurysm. The possibility of occurrence of periarterial fibrosis caused by severe arteriosclerotic changes is discussed.     

Aortic perianeurysmal fibrosis causing bilateral ureteral obstruction: a case report

A 54-year-old male with the chief complaint of bilateral flank pain was admitted to our hospital. Blood chemistry test revealed marked azotemia and retrograde pyelogram showed bilateral hydronephrosis with median shift of narrowed ureters. Abdominal CT scan demonstrated a well-defined dense mass around the aorta implicating bilateral ureters. These findings were interpreted as aortic perianeurysmal fibrosis resulting in bilateral ureteral obstruction. On laparotomy, a large hard mass was found in the lower part of aorta, vena cava, common iliac vessels, inferior mesenteric artery and bilateral ureters. Because of the extension of the mass, ureterolysis and intraperitoneal displacement of ureters wrapped with isolated omentum was performed. Postoperative recovery from azotemia and ureteral obstruction was satisfactory. Biopsy specimen of the mass showed marked fibrosis with non-specific inflammation.     

Partial ureterectomy in a case of intrinsic-type ureteral endometriosis

We report a case of intrinsic-type ureteral endometriosis in a 28-year-old woman. She visited our hospital, complaining of lower abdominal pain. Drip infusion pyelography (DIP) showed left hydronephrosis, and left retrograde pyelography revealed a filling defect of the left pelvic ureter. Biopsy under ureteroscopy showed chronic ureteritis. It was difficult to exclude a malignant tumor, and we performed left partial ureterectomy and uretero-ureterostomy. The pathological examination showed endometrial tissue in the submucosal and muscle layer, and we diagnosed it as intrinsic-type ureteral endometriosis judging from the findings of the ureteroscopy and the operation. After the operation, drip infusion pyelography showed the improvement of the left hydronephrosis and ureteral passage, and the right ovarian endometriosis was found by gynecologists. She received hormonal therapy with the luteinizing hormone releasing hormone agonist for about half a year, but the right ovarian endometriosis remained unchanged. This is the ninth case in the Japanese literature reported as intrinsic-type ureteral endometriosis.     

部分神经肌肉阻滞在神经电生理监测中的应用

背景 在术中神经电生理监测(intraoperative neurophysiologic monitoring,IONM)中,肌肉松弛药(肌松药)由于影响神经肌肉接头兴奋的传递而限制使用. 目的 系统综述部分神经肌肉阻滞(partial neuromuscular blockade,pNMB)对神经电生理监测的影响,详细阐述肌松药在IONM中的应用. 内容 将近年来关于肌松药对IONM的影响及pNMB下的神经电生理监测的文献进行详细整理、系统综述. 趋向 pNMB能为IONM提供良好的监测条件,提高麻醉与手术的安全性.如何合理使用肌松药实现稳定的pNMB还需深入研究和不断探索.     

A case of ureteral triplication associated with ureteropelvic junction obstruction

Ureteral triplication is one of the rarest malformations of the upper urinary tract. The association of ureteral triplication and obstruction is even rarer. We report a case of ureteral triplication associated with hydronephrosis due to ureteropelvic junction (UPJ) obstruction at the middle pole ureter. To our knowledge, such a malformation has not been described previously.