Symptomatic hydronephrosis and ureteric calculi in pregnancy - a narrative review with a proposed management protocol

Navigating the Complexities of Symptomatic Hydronephrosis in Pregnancy

The management of symptomatic hydronephrosis presents substantial challenges due to the absence of consensus within clinical guidelines concerning pain management, diagnostic approaches, therapeutic interventions, and follow-up protocols. This literature review focuses on complexities involving diagnostic challenges that arise from the difficulty in distinguishing physiological from pathological obstruction and treatment complexities that involve deciding on the most appropriate pain management medications and safe interventions while minimizing risks to both the mother and foetus. To address these challenges, a comprehensive search of electronic databases, including PubMed, Embase, and Google Scholar, was conducted for the terms "hydronephrosis", "hydronephrosis in pregnancy", "ionising radiation in pregnancy", and "safe analgesia in pregnancy". Moreover, Mendeley software was used to collect and organize the references. Diagnostic complexities involve selecting the appropriate imaging modality that balances accurate diagnosis with minimal radiation to the foetus. Ultrasound remains the first-line option. However, it has limitations in delineating the underlying aetiology. MRI avoids ionizing radiation but has restricted utility due to foetal movement artifacts. CT provides the highest diagnostic accuracy but raises foetal radiation exposure concerns, though ultra-low dose protocols (<1 mGy) are deemed acceptable by most guidelines. Management includes either a conservative approach, which is a safe option in the majority of cases, or intervention with a percutaneous nephrostomy or ureteric stent insertion, both with comparable symptom control. However, there is no consensus on the optimal frequency for drain changes to prevent rapid encrustation. Definitive procedures like ureteroscopy and percutaneous nephrolithotomies remain controversial. Most guidelines suggest limiting these interventions to specialist centres during the second trimester if required.

Factors predicting the need for surgical intervention for hydronephrosis during pregnancy: a systematic review of the literature

PURPOSE

Symptomatic hydronephrosis in pregnancy can cause both maternal and obstetric complications. In various studies, factors predicting the need for surgical intervention have been evaluated, however these factors have not been systematically assessed yet. This systematic review analyzes published studies about hydronephrosis during pregnancy and determines the predictive factors for the need for surgical intervention for hydronephrosis during pregnancy.

MATERIALS AND METHODS

A systematic review was conducted in January 2023 using the Medline, Web of Science and ScienceDirect/Scopus databases according to PRISMA guidelines. We searched these databases with the following search strategy: (intervention OR nephrostomy OR stent insertion) AND (pregnancy hydronephrosis).

RESULTS

The literature review revealed 2461 potentially eligible studies. After the screening, six studies were enrolled in this review. High neutrophil-to-lymphocyte ratio, high C-reactive protein level, high white blood cell count, high creatinine levels, fever, persistent pain for more than 4 days, presence of ureteral stones more than 8 mm, high grade hydronephrosis, high fetal body weight and high delta resistive index were reported to be related with the need for surgical intervention.

CONCLUSION

The rate of symptomatic hydronephrosis and requirement for surgical intervention is low during pregnancy. However, as symptomatic hydronephrosis may cause serious obstetric complications, it is important to know the parameters that can predict patients who may need surgical intervention. These results will assist gynecologists and urologists to stratify pregnant women for surgical intervention.

Ureteroscopy during pregnancy: Outcomes and lessons learned over 4 decades at a tertiary center in Norway

Background

The management of suspected kidney stone disease in pregnancy is challenging. In cases of persistent flank pain and where investigations may have rendered equivocal results, ureteroscopy (URS) is a recognized diagnostic and therapeutic intervention. This study aimed to investigate the safety and outcomes associated with performing URS during pregnancy, as the technique has evolved over the past 4 decades at our center.

Materials and Methods

We performed a retrospective analysis of pregnant patients who underwent URS at our tertiary center between 1984 and 2022. Outcomes of interest included anesthetic approach, operative time, hospital stay, and complications.

Results

Eighty-seven pregnant patients underwent 96 URS procedures, and 60% (n = 57) of these procedures were performed during the third trimester. Overall, 58% (n = 56) of the procedures were achieved with local anesthesia and light sedation. During the most recent decade, the latter was successfully carried out in 97% of the procedures, with the remainder occurring under spinal anesthesia as per patient choice. Overall, 57% (n = 50) of the whole study group had ureteral calculi found at the time of surgery and in 88% (n = 44) of these cases, fragmentation/extraction was performed. The remainder had insertion of ureteral stent with definitive clearance deferred until postpartum. Mean operative time and postprocedure hospital stay was 33 minutes (range, 7-100 minutes) and 2.2 days (range, 0-16 days), respectively. The overall intraoperative and postoperative complication rates were 2% and 11%, respectively. During the final decade, the latter improved to 6% and all adverse events were minor (Clavien I/II), with the exception of a single case. Regarding exit strategy, ureteral stent was placed in 42% (n = 40) of the procedures, 23% (n = 22) had ureteral catheter inserted, and the remainder (35%, n = 34) had none.

Conclusions

Ureteroscopy can be safely performed during pregnancy using anesthetic approach with local anesthesia and light sedation. Development of a local protocol and multidisciplinary management algorithm are instrumental in enabling the delivery of such a service.