Lower urinary tract effects of ureteral stent length and intravesical position

PURPOSE

Ureteral stents can cause lower urinary tract problems such as stent-related irritative symptoms and urinary tract infections. This study aimed to determine the lower urinary tract effects of ureteral stent length and intravesical position in children.

METHODS

Patients who underwent double-J stenting after urological procedures between January 2017 and January 2022 were included in the study. The patients were assessed in terms of age, irritative symptoms, urinary tract infections, and stent length. The intravesical position of the ureteral stents was grouped as cross-trigonal and ipsilateral. The distribution of irritative symptoms, frequency of urinary tract infections and stent length were analyzed according to intravesical location.

RESULTS

A total of 47 patients were included in the study. The median age was 5 years (range: 1-16). Cross-trigonal stent position was significantly associated with symptoms of urgency (p = 0.046), suprapubic pain (p = 0.002), and lower mean age (p = 0.004). Urinary tract infections were more frequent in patients whose placed stents were longer than recommended (p < 0.001) or were in cross-trigonal position (p = 0.043).

CONCLUSION

Our results suggest that stent-related irritative symptoms and urinary tract infections can be reduced in pediatric patients using a suitably sized ureteral stent and considering its intravesical position.

Longitudinal stent elongation or shortening after deployment in the coronary arteries: which is dominant?

Background

Stent manufacturers always record stent shortening data while they do not record stent elongation data. The aim of this study is to identify both stent shortening and elongation occurring after deployment in the coronary arteries and know their percentage.

Results

The length of coronary stents was measured by intravascular ultrasound (IVUS) by (1) edge-to-edge (E-E) length, measured from the appearance of the first distal strut to the last proximal strut, and (2) area-to-area (A-A) length, measured from the first distal struts seen at more than one IVUS quadrant to the last proximal struts seen at more than one IVUS quadrant. Stent shortening was defined as both E-E and A-A lengths were shorter than the manufacturer box-stated length (shortened group). Stent elongation was defined as both E-E and A-A lengths were longer than the manufacturer box-stated length (elongated group), otherwise unchanged group. Consecutive 102 stents deployed in ischemic patients were included. Stent elongation was detected in 67.6% (69 stents), and shortening was detected in 15.7% (16 stents), while unchanged stents were detected in 16.7% (17 stents). Although the 3 groups had similar box-stated length and predicted foreshortened length, they had significantly different measurements by IVUS, p<0.001 for each comparison. Differences from box-stated length were 1.9±1.4mm, −1.4±0.4mm, and 0.4±0.3mm, respectively, p<0.001. The elongated group had significantly longer differences from the corresponding box-stated and predicted foreshortened lengths, while the shortened group had significantly shorter differences from the corresponding box-stated length and similar foreshortened length. By multinomial regression analysis, the plaque-media area and stent deployment pressure were the independent predictors of the stent length groups, p=0.015 and p=0.026, respectively.

Conclusions

Change in stent length is not only shortening—as mentioned in the manufacturer documents—but also stent elongation. Stent elongation is dominant, and the most important predictors of longitudinal stent changes are plaque-media area and stent deployment pressure.

In vivo measurement of stent length by using intravascular ultrasound

Background

What happens to stent length when deployed in a coronary artery? It is the aim of this study.

Results

Consecutive 95 balloon-expandable stents (BES) were studied by intravascular ultrasound (IVUS) imaging. The stent length was measured from the longitudinal view in two ways: (1) edge-to-edge length (E-E) measured between distal and proximal stent frames located at one IVUS quadrant and (2) area-to-area length (A-A) measured between distal and proximal stent frames located at two or more IVUS quadrants. IVUS measurements were compared with the manufacturer-stated length (M-L). The median E-E length was significantly longer than M-L, 18.76 mm [interquartile range (IQR) 15.65–23.60] versus 18.00 mm (IQR 15.00–23.00), respectively, p < 0.0001. Also, the median A-A length was significantly longer, 18.36 mm (IQR 15.19–23.47), p < 0.0001, than M-L. Moreover, the E-E length was significantly different from A-A length, p < 0.0001. Among the stent groups, the differences were significantly present in all drug-eluting stent and bare metal stent (BMS) comparisons, p < 0.0001, except the A-A length versus M-L in BMS only. By multivariate analysis, the predictors of difference in stent length were as follows: lesion length, p = 0.01; pre-intervention minimal diameter of the external elastic membrane (EEM), p = 0.03; lesions present in the left anterior descending branch, p = 0.03; and M-L, p = 0.04.

Conclusions

In the present study, the length of BES measured by IVUS was significantly different from the manufacturer-stated length. In addition to the manufacturer length, other important factors such as lesion length, pre-intervention diameter of EEM, and affected vessel determine the stent length.

Single- versus multiple-stage catheter-directed thrombolysis for acute iliofemoral deep venous thrombosis does not have an impact on iliac vein stent length or patency rates

BACKGROUND

Incomplete venous thrombolysis and residual nonstented iliac vein disease are known predictors of recurrent deep venous thrombosis (DVT). Controversy exists as to whether the number of thrombolysis sessions affects total stent treatment length or stent patency. The goal of this study was to evaluate the outcomes of patients who underwent single vs multiple catheter-directed lysis sessions with regard to stent extent and patency.

METHODS

Consecutive patients who underwent thrombolysis and stenting for acute iliofemoral DVT between 2007 and 2018 were identified and divided into two groups on the basis of the number of treatments performed (one vs multiple sessions). Operative notes and venograms were reviewed to determine the number of lytic sessions performed and stent information, including size, location, total number, and length treated. End points included total stent length, 30-day and long-term patency, and post-thrombotic syndrome (Villalta score ≥5). The χ2 comparisons, logistic regression, and survival analysis were used to determine outcomes.

RESULTS

There were 79 patients who underwent lysis and stenting (6 bilateral interventions; mean age, 45.9 ± 17 years; 48 female). Ten patients (12 limbs) underwent single-stage treatment with pharmacomechanical thrombolysis, and the remaining 69 (73 limbs) had two to four operating room sessions combining pharmacomechanical and catheter-directed thrombolysis. Patients who underwent a single-stage procedure were older and more likely to have a malignant disease. These patients received less tissue plasminogen activator compared with the multiple-stage group (17.2 ± 2.2 mg vs 27.6 ± 11.6 mg; P = .008). Average stent length was 8.8 ± 5.2 cm for the single-stage group vs 9.2 ± 4.6 cm for the multiple-stage group (P = .764). Patients who underwent a single-stage procedure had no difference in average length of stay from that of patients who underwent multiple sessions (8.5 days vs 5.9 days; P = .269). The overall 30-day rethrombosis rate was 7.3%. Two-year patency was 72.2% and 74.7% for the single and multiple stages, respectively (P = .909). The major predictors for loss of primary patency were previous DVT (hazard ratio [HR], 5.99; P = .020) and incomplete lysis (HR, 5.39; P = .014) but not number of procedures (HR, 0.957; P = .966). The overall post-thrombotic syndrome rate was 28.4% at 5 years and was also not associated with the number of treatment sessions.

CONCLUSIONS

Single- vs multiple-stage thrombolysis for DVT is not associated with a difference in extent of stent coverage. Patency rates remain high for iliac stenting irrespective of the number of lytic sessions, provided lysis is complete and the diseased segments are appropriately stented.

Relationship Between the Intraperitoneal Stent Length in Endoscopic Ultrasound-Guided Hepaticogastrostomy and Surgically Altered Upper Gastrointestinal Anatomy in Patients With Malignant Biliary Obstruction

Background

Endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS) is associated with a relatively high proportion of adverse events, and this is attributable to the lack of standardized protocols and specialized equipment. Although the outcomes of EUS-HGS may differ between patients with and those without surgically altered upper gastrointestinal anatomy, there have been no reports on this topic. The present study aimed to evaluate the efficacy and safety of EUS-HGS using our standardized method and to compare the outcomes between patients with and those without surgically altered upper gastrointestinal anatomy.

Methods

In EUS-HGS, we used a long partially covered metal stent, and we kept the gastric wall pressed with the scope tip until the stent was deployed more than 1 cm inside the working channel of the scope to minimize free space between the liver and gastric wall (the intraperitoneal stent length). A total of 12 patients who underwent EUS-HGS using our method were retrospectively studied. Procedural success and adverse events were evaluated, and the outcomes of EUS-HGS were compared between six patients with and six without surgically altered upper gastrointestinal anatomy.

Results

The procedural success rate was 100%. Additionally, stent migration or dislocation was not noted in any of the patients. The intraperitoneal stent length was significantly greater in patients without surgically altered upper gastrointestinal anatomy than in those with surgically altered upper gastrointestinal anatomy (19.8 mm vs. 11.6 mm; 95% confidence interval, 2.185 - 14.147; P = 0.012).

Conclusions

EUS-HGS using our method was safe. Our findings suggested that special attention should be paid to stent migration or dislocation in patients without surgically altered upper gastrointestinal anatomy.