Use of Indocyanine Green for Intraoperative Perfusion Assessment in Women with Ureteral Endometriosis: A Preliminary Study.

STUDY OBJECTIVE: To evaluate the feasibility, safety, and potential usefulness of near-infrared imaging (NIR) with indocyanine green (ICG) to assess ureteral perfusion after conservative surgery (ureterolysis or nodule removal) for ureteral endometriosis. Any changes to the surgical plan regarding intraoperative ureteral stent placement after NIR-ICG evaluation and early postoperative outcomes were recorded. DESIGN: Prospective case series study. SETTING: Tertiary level referral center for endometriosis and minimally invasive gynecology. PATIENTS: Consecutive symptomatic women scheduled for laparoscopic conservative ureteral surgery for ureteral endometriosis. INTERVENTIONS: After ureterolysis or nodule removal, residual perfusion of the ureters with regular caliber and peristalsis was evaluated through NIR-ICG imaging. Ureteral perfusion grade was defined as absent, irregular, or regular. Time required for NIR-ICG assessment, interoperator agreement regarding ureteral perfusion grade, any changes to the surgical plan after NIR-ICG evaluation, perioperative complications, and clinical-radiologic outcomes at early follow-up were recorded. MEASUREMENTS AND MAIN RESULTS: A total of 31 ureters were examined with NIR-ICG imaging after conservative ureteral procedures. ICG assessment required 5.4 + 2.3 minutes. No complications related to fluorescence imaging were observed. Local ischemia supporting ureteral stent placement was suspected in 5 ureters (16.1%) at white light. Of these, 2 (40.0%) presented regular fluorescence; thus, ureteral stent placement was avoided. In the remaining 3 (60.0%), NIR-ICG confirmed irregular or absent fluorescence, requiring ureteral stent placement. Interoperator agreement regarding NIR-ICG evaluation was high. At a 3-month follow-up, all procedures were clinically and radiologically successful. CONCLUSION: NIR-ICG imaging after conservative surgery for ureteral endometriosis seems to be a feasible, safe, and useful tool to assess ureteral perfusion and guide surgical decision, together with other visual cues at white light. However, this approach needs to be validated by further larger and controlled studies.

Robotic Ureteral Reconstruction.

Robotically assisted laparoscopic techniques may be used for proximal and distal ureteral strictures. Distal strictures may be approached with ureteroneocystotomy, psoas hitch, and Boari flap. Ureteroureterostomy, buccal mucosa graft ureteroplasty, and appendiceal flap ureteroplasty are viable techniques for strictures anywhere along the ureter. Ileal ureteral substitution is reserved for more extensive disease, and autotransplantation is reserved for salvage situations.

Laparoscopic fluorescence navigation for left-sided colon and rectal cancer: Blood flow evaluation, vessel and ureteral navigation, clip marking and trans-anal tube insertion.

BACKGROUND: Recently, the indocyanine green (ICG) fluorescence navigation method has attracted much attention as a means of intraoperative navigation, especially during laparoscopic surgery. The newly developed near-infrared (NIR) fluorescent resin also emits NIR fluorescence, as does ICG. Presently, new devices made with this resin are being developed. The purpose of this study was to present our fluorescence navigation techniques for left-sided colon and rectal cancer. METHOD: Fifty-nine patients with left-sided colon and rectal cancer underwent laparoscopic surgery with fluorescence navigation between July 2019 and April 2020. The surgeries included 54 intestinal blood flow (IBF) evaluations using ICG, 16 preoperative fluorescence clip marking (FCM) procedures, 7 fluorescence ureteral navigation procedures, 4 fluorescence vessel navigation (FVN) procedures during lateral lymph node dissection, and 3 fluorescence-guided trans-anal tube insertion procedures. Laparoscopic surgery and fluorescence observation were performed using a VISERA ELITE 2. In FCM, the Zeoclip FS device was used. In ureteral navigation and trans-anal tube insertion, the Near-Infrared Ray Catheter (NIRC™) fluorescent ureteral catheter (NIRFUC) was used. RESULTS: No complications related to the fluorescence navigation techniques, including those involving ICG, the Zeoclip FS and the NIRFUC, occurred. In 5 cases, the surgical plan was changed according to the IBF evaluation with ICG, and no anastomotic leakage occurred in those cases. These fluorescence navigation techniques provide previously unavailable visual information regarding the IBF, vessel and ureter routes and accurate endoscopic clip and drainage tube locations in the intestinal tract. CONCLUSIONS: Technology to visualize blood flow dynamics and structures using fluorescence can be considered innovative, especially when applied in laparoscopic surgery, which relies on vision. The popularity of fluorescence navigation has also appeared to increase the safety of colorectal surgery. CLINICAL TRIAL REGISTRATION: Examination of fluorescence navigation for laparoscopic colorectal cancer surgery. Research Ethics Committee of the Kawaguchi Municipal Medical Center (Saitama, Japan) approval number: 2020-3. https://kawaguchi-mmc.org/wp-content/uploads/clinicalresearch-r02.pdf.

Detection rate of crossing vessels in pediatric hydronephrosis: Transperitoneal laparoscopy versus open lumbotomy.

BACKGROUND: A bundle of crossing vessels (CV) supplying the lower pole of the kidney and causing mechanical obstruction of the ureteropelvic junction (UPJ) has been the subject of many discussions. During pyeloplasty, it is possible to overlook the CV. This may result in recurrent dilatation of the kidney and the need for re-surgery. OBJECTIVES: To compare the detection rate of CV in UPJ obstruction (UPJO) depending on the operational access applied (transperitoneal laparoscopy (LAP) vs open lumbotomy (OPEN)). Assessment of features that could indicate the presence of CV. MATERIAL AND METHODS: Two hundred and forty-six pediatric pyeloplasties were performed between January 2006 and July 2017 in the Department of Pediatric Surgery and Urology at the Wroclaw Medical University, Poland - 111 out of them by LAP and 135 by OPEN, on 98 girls and 148 boys. A retrospective analysis of the patient records for the detection of CV and characteristics of the CV before surgery was performed. RESULTS: Intraoperative CV causing obstruction of the UPJ in the LAP group were recognized in 34.2% (n = 38) of the patients, and within the OPEN group in 12.5% (n = 17) (p < 0.0001); 90% (n = 27) of patients with the diagnosed CV did not show congenital hydronephrosis. In 68% (n = 21) of the patients there were cases of recurrent renal colic. The presence of CV was suspected in 7.2% of kidney ultrasounds and in 12.5% in computed tomography (CT) urograms. CONCLUSIONS: The detection rate of CV in UPJO is statistically higher in LAP access than in open retroperitoneal lumbotomy. The distinguishing features of patients with CV are the lack of prenatal diagnosis for hydronephrosis and the presence of pain in the lumbar region.

Bone marrow mesenchymal stem cells reduce ureteral stricture formation in a rat model via the paracrine effect of extracellular vesicles.

With no effective therapy to prevent or treat ureteral stricture (US), a multifactorial fibrotic disease after iatrogenic injury of the ureter, the need for new therapies is urgent. Mesenchymal stem cells (MSCs) have been widely studied for treating tissue defects and excessive fibrosis, and recent studies established that one of the main therapeutic vectors of MSCs is comprised in their secretome and represented by extracellular vesicles (EVs). Thus, we have determined to explore the specific role of MSCs-derived EVs (MSC-EVs) treatment in a pre-clinical model of US. The results firstly showed that either a bolus dose of MSCs or a bolus dose of MSC-EVs (administration via renal-arterial) significantly ameliorated ureteral fibrosis and recuperated ureter morphological development in a US rat model. We confirmed our observations through MSCs or MSC-EVs treatment alleviated hydronephrosis, less renal dysfunction and blunted transforming growth factor-ß1 induced fibration. Due to MSC-EVs are the equivalent dose of MSCs, and similar curative effects of transplantation of MSCs and MSC-EVs were observed, we speculated the curative effect of MSCs in treating US might on account of the release of EVs through paracrine mechanisms. Our study demonstrated an innovative strategy to counteract ureteral stricture formation in a rat model of US.

Feasibility of superb microvascular imaging to detect high-grade vesicoureteral reflux in children with urinary tract infection.

OBJECTIVE: To evaluate superb microvascular imaging (SMI) for the detection of high-grade vesicoureteral reflux (VUR). METHODS: We reviewed the patients with urinary tract infection who underwent renal US with SMI and VCUG. The subjects were divided into a VUR group, which included 17 patients (20 kidney units, KU) with high-grade reflux (grade 4 or 5) on VCUG, and a group without VUR including the same numbers of subjects. The direction of urine movement at the distal ureter and the renal pelvis was reviewed on SMI. SMI and VCUG results were compared. RESULTS: Urinary flow "jets" into the bladder and direction of the flow were detectable on all SMI examinations in both groups. In the group with VUR, 20 KUs had grade 4 (n = 11) or grade 5 (n = 9) reflux (bilateral VUR in 3 patients). Among 20 KUs with VUR, 15 (75%) showed a reversed ureteral jet and/or renal pelvic swirl sign on SMI. None of the patients in the group without VUR showed those findings on SMI. CONCLUSION: SMI enables detection of the direction of urinary flow. The presence of a reversed ureteral jet and/or renal pelvic swirl sign correlates with high-grade VUR with 75% accuracy. KEY POINTS: • Superb microvascular imaging is feasible in children with urinary tract infection. • SMI enables detection of the direction of urinary flow. • Presence of reversed flow correlates with high-grade vesicoureteral reflux.

Histopathology in Ureteropelvic Junction Obstruction With and Without Crossing Vessels.

OBJECTIVE: To determine if the histopathology of the ureteropelvic junction differs between those with and without crossing vessels who present with a ureteropelvic junction obstruction (UPJO). MATERIALS AND METHODS: Our database was queried for patients undergoing pyeloplasty (Current procedural terminology 50400, 50405, and 50544) between June 1, 2002, and March 10, 2016. We excluded patients with other renal anatomic abnormalities and patients undergoing surgery for upper tract tumor. One genitourinary pathologist reviewed all slides for muscle hypertrophy, fibrosis, edema, and inflammation. Statistics were modeled in SAS 9.4 (SAS, Cary, NC) using logistic regression with maximum likelihood. RESULTS: A total of 178 patients met the inclusion criteria, and pathology slides were available for 136 patients. Thirty-three patients had crossing vessels in association with a UPJO. The degrees of muscle hypertrophy (P = .89) and fibrosis (P = .17) were not predictive of etiology. The odds of a crossing vessel increased by 4.3 times (95% confidence interval 1.8-9.9) when edema was present (P = .009) and by 4.4 (95% confidence interval 1.4-13.7) times when inflammation was present (P = .0103). CONCLUSION: In the largest pathology series to date, histopathology showed increased inflammation in the presence of a crossing vessel but a similar composition of muscle and fibrosis. These data suggest that UPJO with an associated lower-pole vessel may represent a chronic process, which would explain why patients with a crossing vessel present later in life.

Characterization of the median sacral artery course at the sacral promontory using contrast-enhanced computed tomography.

INTRODUCTION AND HYPOTHESIS: Laparoscopic sacral colpopexy (SC) is increasingly utilized in the surgical management of apical prolapse. It involves attachment of a synthetic mesh to the sacral promontory and to the prolapsed vaginal walls. The median sacral artery (MSA) runs close to the site of mesh attachment and is therefore prone to intraoperative injury, which may lead to profound hemorrhaging. The aim of this study was to determine the location of the MSA at the level of the sacral promontory with regard to adjacent visible anatomical landmarks. Surgeons may use this information to reduce the risk for presacral bleeding. METHODS: Sixty consecutive contrast-enhanced pelvic computed tomography scans were revised, and the location of the MSA at the level of the sacral promontory was determined in relation to the ureters, iliac arteries, sacral midline, and aortic bifurcation. RESULTS: The MSA runs 0.2 ± 3.9 mm left to the midline of the sacral promontory and 48.0 ± 15.4 mm caudal to the aortic bifurcation. The ureters, internal and external iliac arteries on the right were significantly closer to the MSA than on the left (30.0 ± 7.1 vs 35.2 ± 8.8 mm, p = 0.001; 21.5 ± 6.8 vs 30.3 ± 8.4 mm, p < 0.0001; 32.8 ± 10.2 vs 41.9 ± 14.5 mm, p = 0.005 respectively). CONCLUSIONS: The MSA, which runs left to the midline of the sacral promontory, and its location can be determined intraoperatively in relation to adjacent visible anatomical structures. The iliac vessels and ureter on the right are significantly closer to the MSA than those on the left. This information may help surgeons performing SC to avoid MSA injury, thus reducing operative morbidity.

Ureteropelvic junction obstruction in children by polar vessels. Is laparoscopic vascular hitching procedure a good solution? Single center experience on 35 consecutive patients.

PURPOSE: We report the results of laparoscopic vascular hitching (LVH) in a series of children with ureteropelvic junction obstruction (UPJO) owing to aberrant lower polar crossing vessels (CV). Our aim is to confirm if LVH associated with intraoperative diuretic test (DT) represents a good procedure to treat extrinsic-UPJO by CV. In order to confirm the relief of the obstruction we suggest performing an intraoperative DT. MATERIALS AND METHODS: In our department from 2006 to 2014, 120 patients were treated for both extrinsic and intrinsic-UPJO. 85 (30 females, 55 males) presented an intrinsic obstruction and underwent dismembered pyeloplasty (AHDP), 61 open, 16 laparoscopic, 8 retroperitoneoscopic. 35 (23 males, 12 females) were studied for a suspected extrinsic-UPJO: 30 were treated with LVH (modified Hellström vascular hitch). Intraoperative-DT was performed in all patients before and after vessel transpositions confirming the UPJO and eventual relief after the procedure. We included in the study only patients with suspicion of vascular extrinsic-UPJO. Average age at surgery was 7.5years. Symptoms of presentation were recurrent abdominal/flank pain and hematuria. All patients presented ultrasound (US) detection of hydronephrosis. Preoperative diagnostic studies include: US/doppler scan, MAG3 renogram, urography, functional magnetic resonance urography (fMRU) and CT scan. RESULTS: 28 out 35 patients had a correct preoperative diagnosis, and the remaining needed an intraoperative diagnosis confirmation. All 35 patients had an intraoperative-DT: 30 patients underwent LVH (positive-DT); 3 patients (negative-DT) underwent laparoscopic-AHDP for intrinsic-UPJO; two with positive-DT and nonobstructive CV, had no surgical treatment. Median operating time was 95min; mean hospital stay was 4days. At 12-84months follow-up 29 patients remained symptoms-free, one needed after two years a laparoscopic-AHDP. CONCLUSIONS: According our experience, LVH associated with intraoperative-DT may be considered a safe procedure to treat extrinsic-UPJO by CV in carefully selected patients. In particular, the very low incidence of relapse suggest that in suspicion of extrinsic-UPJO, performing intraoperative-DT after CV transposition allows to exclude intrinsic-UPJO confirming that the LVH-procedure has relieved the pelvic obstruction, precluding the need for AHDP.

Differences between intrinsic and extrinsic ureteropelvic junction obstruction related to crossing vessels: histology and functional analyses.

PURPOSE: In children, ureteropelvic junction obstruction (UPJO) is mostly caused by intrinsic factors (IUPJO); extrinsic UPJO are rare and often due to crossing vessels (CVs). METHODS: We retrospectively reviewed all data of children with UPJO that underwent surgery in our institution from 2004 to 2011. Analyses included age at surgery, gender, preoperative and postoperative results of ultrasound and renal scans [differential renal function (DRF); signs of obstruction], and pathology reports. Available histological specimens of cases with CV were compared to a random selection of intrinsic cases in a blinded fashion. After additional Masson's trichrome staining, the specimens were scored for fibrosis, muscular hypertrophy, and chronic inflammation. RESULTS: Out of 139 patients with UPJO, 39 cases were associated with CV. Median age at surgery was 68 months (range 2-194) in the CV group and 11.5 months (range 0-188) in IUPJO group. Laparoscopic dismembered pyeloplasty (LDMP) was carried out in 134 and open DMP in five patients. Preoperative ultrasound identified 28/39 cases with CV. DRF below 40 % was more frequently seen in CV patients (p = 0.020). Histological analyses revealed no differences between the CV and IUPJO specimens in total. CV patients with higher grades of muscular hypertrophy had lower preoperative DRF, compared to those with higher preoperative DRF (p = 0.026). Functional recovery after (L)DMP was excellent in both groups. CONCLUSION: We could not find any significant histological differences between CV and IUPJO in children. To obtain excellent functional recovery, surgical procedures with a definite correction of the UPJ should be preferred in paediatric patients with CV.

Evidence that NO/cGMP/PKG signalling cascade mediates endothelium dependent inhibition of IP3R mediated Ca²âº oscillations in myocytes and pericytes of ureteric microvascular network in situ.

In ureteric microvessels the antagonistic relationship between Ca(2+) signalling in endothelium and Ca(2+) oscillations in myocytes and pericytes of arterioles and venules involves nitric oxide (NO), but the underlying mechanisms are not well understood. In the present study we investigated the effects of carbachol and NO donor SNAP on Ca(2+) signalling and vasomotor responses of arterioles and venules in intact urteric microvascular network in situ using confocal microscopy. Vasomotor responses of arterioles and venules induced by AVP correlated with the occurrence of Ca(2+) oscillations in the myocytes and pericytes and were not abolished by the removal of Ca(2+) from extracellular fluid. Carbachol-induced rise of intracellular Ca(2+) in endothelium was accompanied by the termination of the Ca(2+) oscillations in myocytes and pericytes. This carbachol-induced inhibitory effect on Ca(2+) oscillations in myocytes and pericytes was reversed by ODQ, an inhibitor of soluble guanylyl cyclase (sGC) and by Rp-8-pCPT-cGMPS, an inhibitor of protein kinase G (PKG). Ca(2+) oscillations in myocytes and pericytes were also effectively blocked by NO donor SNAP. An Inhibitory effect of SNAP was markedly enhanced by zaprinast, a selective inhibitor of cGMP-specific phosphodiesterase-5, and reversed by sGC inhibitor, ODQ and PKG inhibitor, Rp-8-pCPT-cGMPS. The cGMP analogue and selective PKG activator 8pCPT-cGMP also induced inhibition of the AVP-induced Ca(2+) oscillations in myocytes and pericytes. SNAP had no effects on Ca(2+) oscillations induced by caffeine in distributing arcade arterioles. Consequently, we conclude that NO- mediated inhibition of Ca(2+) oscillations in myocytes and pericytes predominantly recruits the cGMP/PKG dependent pathway. The inhibitory effect of NO/cGMP/PKG cascade is associated with suppressed Ca(2+) release from the SR of myocytes and pericytes selectively via the inositol triphosphate receptor (IP3R) channels.

[Functional outcomes obtained after vesicoureteral reimplantation surgery in adults: A review]. / Étiologies et résultats fonctionnels après réimplantation urétéro-vésicale chez l'adulte : revue de la littérature.

OBJECTIVES: Vesico-ureteral reimplantations (VUR) for adults are complex procedures, often practicing for distal ureteral lesions. Our goal was to synthesis the main indications for VUR, different techniques and their functional outcomes. MATERIAL AND METHODS: A literature review in English by Medline, Embase and Google scholar was performed using the following keywords: ureter; laparoscopy; robotics, reimplantation; surgery; obstruction; morbidity; complications; psoas hitch; Boari flap; ureteroneocystostomy. RESULTS: In more than half of the cases, aetiology was a iatrogenic ureteral lesion. When the ureteral defect was less than 2 cm, direct or non-refluxing VUR was the technique of choice. If defect was superior than 2 cm the Boari flap or vesicopsoas hitch were preferred. Several surgical approaches were feasible: open, laparoscopic only, robot assisted laparoscopic. Estimated blood loss, pain and mean hospital stay seemed better with conventional or robotic coelioscopy. Nevertheless, complications, pre-/post-operative renal function and mean operative time seemed similar. The most frequent major complication was the anastomotic urine leakage. CONCLUSIONS: The VUR techniques are well codified now even if it's a rare procedure. Functional outcomes are satisfied according to literature and morbidity is more and more decreasing but the level of evidence of the studies is low.

Pediatric ureteropelvic junction obstruction: can magnetic resonance urography identify crossing vessels?

BACKGROUND: MR Urography (MRU) is an increasingly used imaging modality for the evaluation of pediatric genitourinary obstruction. OBJECTIVE: To determine whether pediatric MR urography (MRU) reliably detects crossing vessels in the setting of suspected ureteropelvic junction (UPJ) obstruction. The clinical significance of these vessels was also evaluated. MATERIALS AND METHODS: We identified pediatric patients diagnosed with UPJ obstruction by MRU between May 2009 and June 2014. MRU studies were evaluated by two pediatric radiologists for the presence or absence of crossing vessels. Ancillary imaging findings such as laterality, parenchymal thinning/scarring, trapped fluid in the proximal ureter, and presence of renal parenchymal edema were also evaluated. Imaging findings were compared to surgical findings. We used the Mann-Whitney U test to compare continuous data and the Fisher exact test to compare proportions. RESULTS: Twenty-four of 25 (96%) UPJ obstructions identified by MRU were surgically confirmed. MRU identified crossing vessels in 10 of these cases, with 9 cases confirmed intraoperatively (κ = 0.92 [95% CI: 0.75, 1.0]). Crossing vessels were determined to be the primary cause of UPJ obstruction in 7/9 children intraoperatively, while in two children the vessels were deemed incidental and noncontributory to the urinary tract obstruction. There was no significant difference in age or the proportions of ancillary findings when comparing children without and with obstructing vessels. CONCLUSION: MRU allows detection of crossing vessels in pediatric UPJ obstruction. Although these vessels are the primary cause of obstruction in some children, they are incidental and non-contributory in others. Our study failed to convincingly identify any significant predictors (e.g., age or presence of renal parenchymal edema) that indicate when a crossing vessel is the primary cause of obstruction.

Detection of crossing vessels in pediatric ureteropelvic junction obstruction: Clinical patterns and imaging findings.

BACKGROUND: Pediatric ureteropelvic junction obstruction (UPJO) is caused by congenital intrinsic narrowing and/or a lower pole-crossing renal artery. When a crossing renal vessel (CRV) is missed at the time of pyeloplasty, a redo-pyeloplasty is often required. OBJECTIVES: The aims were to analyze clinical predictors for the presence of a CRV in UPJO and the utility of functional magnetic resonance urography (fMRU) in preoperative identification of a crossing vessel. METHODS: Using an Institutional Review Board approved registry database, we identified 166 patients from July of 2007 until January of 2014 who had undergone open, laparoscopic, or robotic assisted laparoscopic pyeloplasty at our institution. We abstracted data including age at surgery, preoperative symptoms, preoperative imaging findings, and whether or not a CRV was identified intraoperatively. Statistical analysis was performed on SPSS using the Mann-Whitney U test. RESULTS: Of the 166 patients identified, 78 were found to have a CRV at the time of surgery and 88 did not. The surgical approach was distributed as 104 robotic assisted laparoscopic, 51 open, and 11 pure laparoscopic. On univariate analysis, older age at presentation and pain at presentation predicted the presence of a CRV; antenatal hydronephrosis was a negative predictor, though 20 of 68 (25.6%) infants diagnosed with UPJO antenatally did have a CRV. Subgroup analysis of patients undergoing preoperative MRU showed a sensitivity of 88.2% and specificity of 91.7% for the detection of CRVs. DISCUSSION: This study confirmed the importance of looking for a crossing vessel in all cases, with the knowledge that increased age and pain at presentation were more likely to be associated with a crossing vessel. In addition, fMRU is a valuable source of information in the preoperative identification of the presence of a crossing vessel. The study has limitations including being retrospective in nature, and that the sensitivity of fMRU to identify CRVs was based on the read of an experienced uroradiologist who specializes in MRU, so may not correlate with the standard clinical read of an fMRU. CONCLUSION: This study confirms the need to maintain a high index of suspicion for the presence of a CRV when intervening in a clinically symptomatic older child, although 25% of infants with antenatally detected UPJO did have one too. Our subset analysis demonstrated that MRU is a reliable method of detecting crossing vessels.

An unusual combination of extra-adrenal pheochromocytoma and arteriovenous malformation of the ureter in a young adult.

We present a case of a 24-year-old gentleman who presented with painless pan haematuria for 2 weeks. During the workup, he was diagnosed to have a retrocaval mass after a CT scan while cystoscopy revealed a polypoidal pulsating lesion in the left ureter. After surgical manipulation of the retrocaval mass, the blood pressure of the patient raised to 260/130 mm Hg. It was completely resected and diagnosed as extra-adrenal pheochromocytoma (paraganglioma) after histopathology. The lesion in the ureter was completely excised and fulgurated and diagnosed as an arteriovenous malformation. To the best of our knowledge, this is the first patient to be presented in the literature with this unusual combination.

Morphological analysis of rat ureteric terminal arterioles in situ.

Confocal imaging of Fluo-4, Propidium iodide, and di-8-Anepps loaded ureter were used to study the morphology of terminal arterioles with an inner diameter <50 µm in intact rat ureter. Optical sectioning showed that the muscle coat of the terminal arterioles consisted of a monolayer of highly curved smooth muscle cells which run circumferentially around the endothelium. This technique allowed not only to measure the inner diameter of the terminal arterioles but also to define the orientation and number of revolutions an individual smooth muscle cell made around the endothelium. We measured thickness, width, length, and morphological profile of the myocytes and endothelial cells. Propidium iodide staining showed nuclei of individual cells by continuous imaging at high resolution in serial optical sections. Conventional haematoxylin-eosin, Masson's tri-chrome staining, and transmission electron microscopy were also used in this study to compare the measurements obtained from live confocal imaging with histological standard methods. Parameters obtained from live imaging were significantly different. This technique of live staining allowed measuring the cellular and nuclear dimensions of the terminal arterioles in their natural environment which are important in studying the effects of vascular disease or aging on vascular structure.

Retroperitonoscopic pyelopexy for pelviureteral junction obstruction with crossing vessel in adolescents: Hellstrom principle revisited.

OBJECTIVE: To present our new approach using a minimally invasive technique for the management of pelviureteral junction (PUJ) obstruction with a crossing vessel. MATERIALS AND METHODS: In December 2009 to December 2011, out of 23 cases of retroperitoneoscopic laparoscopic pyeloplasty, four adolescents presenting with PUJ obstruction due to an aberrant crossing vessel, with intermittent attacks of renal colic and mild dilatation of the renal pelvis and calyces, were operated by retroperitoneoscopic pyelopexy. A retroperitoneoscopic approach was used in all patients using three trocars. After dissection of the PUJ from the anterior crossing vessel, and ensuring good funneling of the PUJ that proved to show mild dilatation, an interrupted 3/0 polyglycolic suture was used to fix the renal pelvis to the psoas muscle away from the crossing vessel (pyelopexy). A retrograde DJ stent was placed at the end of the procedure. RESULTS: The four patients had a mean age of 18.25 years (16-20): 2 males and 2 females, two right sided and two left sided. Average operative time was 46 min (40-55). All patients were discharged on the same day. No intraoperative complications were encountered. The DJ stent was removed 6 weeks postoperatively. After a mean follow up of 2.125 years (6 months-3 years) no recurrences were observed. CONCLUSION: Retroperitoneoscopic pyelopexy is shown to be a reliable, effective, safe and minimally invasive technique for the management of PUJ obstruction with a crossing vessel in selected cases. Long-term follow up is needed to assess any recurrence or development of complications.

Lower pole vessels in children with pelviureteric junction obstruction: laparoscopic vascular hitch or dismembered pyeloplasty?

OBJECTIVE: To choose between laparoscopic "vascular hitch" (VH) and dismembered pyeloplasty (DP) in treatment of aberrant lower pole crossing vessels potentially responsible for pelviureteric junction obstruction (PUJO) in older children. PATIENTS AND METHODS: Retrospective study of 19 patients treated laparoscopically for PUJO. Based on videos of the procedures, we studied the anatomical relationship between the renal pelvis, the pelviureteric junction, and the aberrant vessels. RESULTS: Eight patients had laparoscopic VH and 11 had DP. All patients with DP needed drainage. In the VH group, 7/8 patients were asymptomatic and had decreased pelvic dilation. Half of them accepted MAG3 scintigraphy, and in these patients the obstructive syndrome disappeared completely. The last patient in this group was lost to follow-up. We observed three anatomical variations in the location of polar vessels: type 1 (in front of the dilated pelvis), type 2 (in front of the pelviureteric junction), type 3 (under the pelviureteric junction, resulting in ureteral kinking). CONCLUSION: Laparoscopic VH is a simple technique involving no urinary anastomosis or drainage, but we cannot guarantee that the crossing vessels are the sole etiology for PUJO. Following our experience, only patients with type 3 anatomical variations and with a normal pelviureteric junction should be proposed for VH.