Congenital midureteral stenosis in children: a 13-year retrospective study based on data from a large pediatric medical center

Background Midureteral stenosis is very rare in children and can cause congenital hydronephrosis. We report our experience treating children with congenital midureteral stenosis at our center, focusing on the differences in preoperative diagnosis and treatment compared with other congenital obstructive uropathies. Methods We retrospectively reviewed the medical records of 26 children diagnosed with congenital midureteral stenosis at our center between January 2007 and December 2020, such as preoperative examination methods, intraoperative conditions, and postoperative follow-up results. Results Of the 1625 children treated surgically for ureteral narrowing, only 26 (1.6%) were diagnosed with midureteral stenosis, including 15 infants and 11 children. Eighteen (69.2%) were boys, 13 (50%) were affected on the left side, and 23 (88.5%) had isolated ureteral stenosis. Overall, 13 (50%) of the children presented with prenatal hydronephrosis, and 13 (50%) presented with abdominal pain or a mass. All the children had undergone urinary ultrasound and intravenous urography preoperatively; the diagnostic rate of ultrasound was 92.3%. Only 7 (26.9%) children had undergone pyelography. All the children had undergone surgery. The ureteral stenotic segment was less than 1 cm long in 25 (96.2)% of the children. The mean follow-up duration was 22 months (range: 6–50 months). One child developed anastomotic strictures. Urinary tract obstruction was relieved in the other children without long-term complications. Conclusions Congenital midureteral stenosis is rare, accounting for 1.6% of all ureteral obstructions, and its diagnosis is crucial. Urinary ultrasound has a high diagnostic rate and should be the first choice for midureteral stenosis. Retrograde pyelography can be used when the diagnosis is difficult, but routine retrograde pyelography is not recommended. Congenital ureteral stenosis has a relatively short lesion range, largely within 1 cm. The treatment is mainly resection of the stenotic segment and end-to-end ureteral anastomosis, with a good prognosis.

Congenital Midureteral Stenosis in Children: A 13-year Retrospective Study based on Data from a Large Pediatric Medical Center

Background: Midureteral stenosis is very rare in children and can cause congenital hydronephrosis. We report our experience treating children with congenital midureteral stenosis at our center, focusing on the differences in preoperative diagnosis and treatment compared with other congenital obstructive uropathies.Methods: We retrospectively reviewed the medical records of 26 children diagnosed with congenital midureteral stenosis at our center between January 2007 and December 2020, including preoperative examination methods, intraoperative conditions, and postoperative follow-up results.Results: Of the 1625 children treated surgically for ureteral narrowing, only 26 (1.6%) were diagnosed with midureteral stenosis, including 15 infants and 11 children; 68% were boys; 48% were affected on the left side; and 88% had isolated ureteral stenosis. In all, 50% of the children presented with prenatal hydronephrosis, and 50% presented with abdominal pain or a mass. All children underwent urinary ultrasound and intravenous urography (IVU) preoperatively; the diagnostic rate of ultrasound was 92.3%. Only 7 (26.9%) children underwent pyelography. All children underwent surgery. The ureteral stenotic segment was less than 1 cm long in 96% of the children. The mean follow-up duration was 22 months (range: 6-50 months). One child developed anastomotic strictures. Urinary tract obstruction was relieved in the other children without long-term complications.Conclusions: Congenital midureteral stenosis is rare, accounting for 1.6% of all ureteral obstructions, and its diagnosis is very important. Urinary ultrasound has a high diagnostic rate and should be the first choice for midureteral stenosis. Retrograde pyelography can be used when diagnosis is difficult, but routine retrograde pyelography is not recommended. Congenital ureteral stenosis has a relatively short lesion range, largely within 1 cm. The treatment is mainly resection of the stenotic segment and end-to-end ureteral anastomosis, with a good prognosis.

Surgical repair of a special category of arteriovenous fistula outflow stenosis caused by venous valve hyperplasia

Objective This study evaluated a special category of arteriovenous fistula outflow stenosis caused by venous valve hyperplasia and explored the effectiveness of surgical repair in dealing with this kind of stenosis. Study design This retrospective cohort study was conducted from February 2016 to January 2020 in our center. Patients with arteriovenous fistula dysfunction, including flow rate insufficiency, venous hypertension, thrombosis, and aneurysm dilation enlargement, were selected. Stenosis lesions presenting with venous valve hyperplasia were selected after ultrasound screening. All patients underwent surgical repair and were followed up every 6 months after surgery. Results Forty-three patients (median age, 54.5 ± 11.2 years; 65.1% men) were included. All procedures were technically successful. Based on intraoperative exploration, 56.5% were reconstructed via autologous vein patch, 17.4% of patients were reconstructed with end-to-end reconstruction after cutting the stenotic segment, 13.0% of cases simply had the valve resected, and 13.0% of cases involved a longitudinal incision and transverse suture. All patients returned to routine dialysis the following day and avoided catheter insertion. The mean follow-up time was 22.5 ± 14.0 (range, 1.3–49.8) months. The patency rates at 2 and 4 years were 92.2% and 79.0%, respectively. Valves harvested from patients were analyzed via Masson staining and immunohistochemical staining, indicating collagen fiber and myofibroblast hyperplasia in outflow venous valve hyperplasia (OVVH). Conclusions Outflow venous valve hyperplasia can lead to fistula dysfunction. Ultrasound is the main method to diagnosis OVVH. Special surgical repair can preserve valuable vascular resources and relieve stenosis, is safe and effective, and has a high patency rate.

High-Frame Rate Vector Flow Imaging Technique: Initial Application in Evaluating the Hemodynamic Changes of Carotid Stenosis Caused by Atherosclerosis

Objective: To investigate the value of high-frame rate vector flow imaging technique (V flow) in evaluating the hemodynamic changes of carotid stenosis caused by atherosclerotic plaques.Methods and Materials: In this prospective study, patients with stenosis rate (diameter) ≥30% caused by carotid atherosclerotic plaques were included. Degrees of carotid stenosis were graded according to North American Symptomatic Carotid Endarterectomy Trial criteria: moderate (30–69%) or severe (70–99%). Mindray Resona 7s ultrasound machine with a linear array transducer (3–11 MHz) was used for ultrasound examinations. The mean WSS value of carotid arteries was measured at the proximal, narrowest region and distal of carotid stenosis. The mean WSS values were correlated with peak systolic velocity (PSV) measured by color Doppler flow imaging and stenosis degree detected by digital subtraction angiography (DSA). The vector arrows and flow streamline detected by V flow dynamic imaging were analyzed. Imaging findings of DSA in carotid arteries were used as the gold standard.Results: Finally, 51 patients were included. V flow measurements were performed successfully in 17 patients (100%) with moderate-grade stenosis and in 30 patients (88.2%) with severe-grade stenosis. Dynamic V flow imaging showed yellow or red vectors at the stenotic segment, indicating fast speed blood flow (up to 260.92 cm/s). Changes of streamlines were detected in the stenotic segment. The mean WSS value measured at the narrowest region of the carotid artery had a moderately positive correlation with stenosis degree (r = 0.58, P < 0.05) and PSV value (r = 0.54, P < 0.05), respectively. Significant difference was detected in mean WSS value at the narrowest region of the carotid artery between severe carotid stenosis (1.47 ± 0.97 Pa) and moderate carotid stenosis (0.96 ± 0.44 Pa) (P < 0.05).Conclusion: The hemodynamic changes detected by V flow of the carotid stenosis might be a potential non-invasive imaging tool for assessing the degree of carotid stenosis.

Topical application of mitomycin C as an adjunct in treating subglottic stenosis

Topical application of mitomycin C is best used as an adjunct in airway surgeries together with combination of other modalities of endoscopic techniques such as excision, balloon dilatation and laser treatment in treating subglottic stenosis. We present a case of a 12-year-old boy who acquired Cotton–Myer grade 3 subglottic stenosis 6 months post endotracheal intubation. The stenotic segment was treated with cautery-assisted excision followed by balloon dilatation and topical application of mitomycin C at the raw area. The patient recovered well with improvement of airway diameter, no more symptoms, no more events of restenosis and without the need for multiple procedures.

Spontaneous recanalization of occluded transplant renal artery: a rare case report

Background Transplant renal artery stenosis (TRAS) is a serious vascular complication that occurs after renal transplantation and can result in hypertension, renal functional impairment, and graft loss. Endovascular treatment has become the first-line treatment for TRAS because of its low invasiveness and high success rate. Case presentation A 23-year-old female with end-stage renal disease of unknown cause received a living-donor kidney transplantation 10 months ago. Seven months after the transplantation, her blood pressure gradually deteriorated. Magnetic resonance angiography revealed bending and stenosis of the transplant renal artery, and the patient received endovascular treatment. A digital subtraction angiography revealed significant stenosis of 95% in the proximal transplant renal artery. The guidewire could not pass through the stenotic segment of the transplant renal artery even with repeated attempts by the surgeons; as a result, the transplant renal artery became occluded, and vasodilators were ineffective. After the operation, renal function gradually worsened, so she began to receive regular dialysis. Twenty-five days later, the patient’s urine volume was significantly higher than that before, and ultrasound showed that the proximal transplant renal artery was not completely occluded. A re-intervention was performed, and the stent was placed successfully in the stenotic segment. After the operation, renal function gradually recovered, and dialysis was no longer needed. Conclusion Patients with iatrogenic transplant renal artery occlusion may have the possibility of spontaneous recanalization, which can help prevent the need for re-transplantation.

Orally Inhaled Drug Particle Transport in Computerized Models of Laryngotracheal Stenosis

Objective Adjuvant management for laryngotracheal stenosis (LTS) may involve inhaled corticosteroids, but metered dose inhalers are designed for pulmonary drug delivery. Comprehensive analyses of drug particle deposition efficiency for orally inhaled corticosteroids in the stenosis of LTS subjects are lacking. Study Design Descriptive research. Setting Academic medical center. Methods Anatomically realistic 3-dimensional reconstructions of the upper airway were created from computed tomography images of 4 LTS subjects—2 subglottic stenosis and 2 tracheal stenosis subjects. Computational fluid dynamics modeling was used to simulate airflow and drug particle transport in each airway. Three inhalation pressures were simulated, 10 Pa, 25 Pa, and 40 Pa. Drug particle transport was simulated for 100 to 950 nanoparticles and 1 to 50 micron-particles. Particles were released into the airway to mimic varying inhaler conditions with and without a spacer chamber. Results Based on smallest to largest cross-sectional area ratio, the laryngotracheal stenotic segment shrunk by 57% and 47%, respectively, for subglottic stenosis models and by 53% for both tracheal stenosis models. Airflow resistance at the stenotic segment was lower in subglottic stenosis models than in tracheal stenosis models: 0.001 to 0.011 Pa.s/mL vs 0.024 to 0.082 Pa.s/mL. Drug depositions for micron-particles and nanoparticles at stenosis were 0.06% to 2.48% and 0.10% to 2.60% for subglottic stenosis and tracheal stenosis models, respectively. Particle sizes with highest stenotic deposition were 6 to 20 µm for subglottic stenosis models and 1 to 10 µm for tracheal stenosis models. Conclusion This study suggests that at most, 2.60% of inhaled drug particles deposit at the stenosis. Particle size ranges with highest stenotic deposition may not represent typical sizes emitted by inhalers.

Inter-vertebral Height, Inter-vertebral Foramen Height and Range of Motion are Associated with Redundant Nerve Roots in Lumbar Spinal Stenosis

Background: To analyze the relational factors influencing the formation of cauda equina redundant nerve roots (RNRs) of the lumbar spinal stenosis.Methods: A retrospective study of 116 patients with lumbar spinal stenosis were treated in our department from January 2016 to June 2019. Magnetic resonance imaging (MRI) was performed to observe the shape and morphology of the redundant nerve roots of the cauda equina.We divided patient into (RNRs) group and non-RNRs( NRNRs) group based on the presence or absence of RNRs on sagittal T2-weighted MR. We analyzed the demographic characteristics, preoperative back pain visual analogue scale (VAS) scores ,preoperative leg pain VAS scores, and preoperative Oswestry disability index(ODI) scores, and also analyzed the rate of spondylolisthesis and ligamentum flavum hypertrophy. Simultaneously,the inter-vertebral height, intervertebral foramen height, inter-vertebral height +vertebral height, median sagittal diameter at the inter-vertebral space level(DIW-MSD),median sagittal diameter at the pedicel level(DV-MSD),ROM of the stenotic segment, were statistically analyzed for clinical and radiological significance.Results : Of a total 116 total patients,there were no statistically significant differences in either gender [RNRs group (n = 42, 18/24 female) and NRNR group (n = 74, 38/36 female)], age, BMI index, preoperative back pain VAS score , preoperative leg pain VAS score and preoperative ODI score(p> 0.05);however, there were statistically significant differences regard to the duration of symptoms and the rate of spondylolisthesis and ligamentum flavum hypertrophy (p<0.05);the inter-vertebral height,Intervertebral foramen height, inter-vertebral height+vertebral height, DIW-MSD ,ROM of the stenotic segment were also significantly different between the group (p<0.05).Conclusions:The inter-vertebral height, inter-vertebral foramen height, inter-vertebral height + vertebral height, DIW-MSD and ROM of the stenotic segment were the crucial factors related to RNRs in lumbar spinal stenosis.

Superior Strategy in Benign Tracheal Stenosis Treatment: Surgery or Endoscopy?

Introduction Due to the variations in (laryngeal) tracheal stenosis (TS) patient groups, there is still no consensus on which patient should be treated with endoscopy or surgery. The aim of the present study was to generate an algorithm in the light of the related literature and the data obtained from a clinic where both endoscopic and surgical treatments are conducted. Method A retrospective analysis was performed on the data of a total of 56 patients during 2013 to 2019. A total of 38 patients were subject to surgery with 31 as a first treatment option and 7 due to the unsatisfactory results of endoscopic treatments. Endoscopic approaches were tried on a total of 29 patients with 25 as initial treatment and 4 due to postsurgical recurrence. Results Symptomatic full control ratio was determined as 69% with endoscopic treatments, 89.5% in subglottic stenosis (SGS) surgery (n = 19), and 89.5% in trachea surgery (n = 19). However, success rates with no recurrence were determined, respectively, as 40.0, 36.4, and 36.4% for patients subject to dilatation, stent, or T tube treatment. Dilatation was observed to be successful in patients with stenotic segment lengths of less than 1.5 cm (p = 0.02). Failure rates increased in SGS (p = 0.03) and TS (p = 0.12) in the surgical group with increasing stenotic segment length. The presence of comorbidities was not effective on treatment success. Conclusion Endoscopic methods are preferred in cases of web-like stenosis. Surgical methods should first be considered for other patients and endoscopic methods should be used on patients who are not suited for surgery or in cases of postsurgical recurrence.

Fistula Salvage Open Thrombectomy in a Pediatric Patient

Highlights Early arteriovenous fistula is advocated in children requiring hemodialysis. Lifelong usage requires long-term preservation of fistula. Thrombosis is the leading cause of arteriovenous fistula complication secondary to stenosis and can be addressed using and open thrombectomy. A case of successful fistula salvaging surgical intervention via open thrombectomy, resection of short stenotic segment, and veno-venous anastomosis procedure. An emphasis on salvaging to preserve precious vessels in children as opposed to creating a new one.