Background and purpose
Malignant conditions of the pelvis and/or abdomen can cause ureteric obstruction and associated impaired renal function, which can be managed by performing percutaneous nephrostomy (PCN) tube insertion. Nephrostomy tubes are associated with prolonged hospital stay which affects quality of life. The main objective of this study was to assess the changes in estimated glomerular filtration rate (eGFR) over the first six months following percutaneous nephrostomy for malignant ureteric obstruction. We also explored the role of UTIs in the changes of eGFR following PCN.
Materials and Methods
We performed a retrospective folder review of patients who had PCN procedures at Groote Schuur Hospital for malignant obstructive uropathy from January 2015 to 31 December 2017. For each included patient, eGFR was recorded at baseline pre-PCN, and at its best and worst value in the first six months after PCN. The timing of baseline, best and worst values were also recorded. Other data collected included demographic data, type of malignancy, laterality of nephrostomy and presence of confirmed UTI at least one week post PCN.
Results/main findings
A total of 90 patients fulfilled our inclusion criteria. The most common cancers in men were bladder 59% (n=32), prostate 20% (n=11), lymphoma 7% (n=4), and colorectal 4% (n=2). The most common cancers in women were cervix 64% (n=23), bladder 19% (n=7), lymphoma 6% (n=2), colorectal 6% (n=2) and endometrial 6% (n=2). Men were of higher age, median (IQR), 60 (56, 67) years, compared to women, 48 (40, 67). 64% of patients (n=58) had bilateral PCN procedures (as opposed to a unilateral procedure). 52% (n=47) of patients developed at least one episode of UTI post PCN during the six-month observation period. Median (IQR) timepoint of pre-PCN eGFR measurement was 1.0 (2.0, 0) day pre PCN. The best post-PCN eGFR measurement was 13.0 (6.0, 26.0) days post PCN. The worst post-PCN measurement was 33.5 (14.0, 92.5) days post PCN. Pre-PCN eGFR, median (IQR), was 9 (5, 26). Post-PCN eGFR improved to 48 (30, 75) before deteriorating to 23 (9, 44) within the six-month follow-up window. Compared to patients who do not develop UTI post-PCN, those who develop one or more post-PCN UTI(s) have a 6.15 (95% CI: 0.87, 11.43) unit lower eGFR at their worst eGFR measurement. There are also markedly fewer deteriorations in chronic kidney disease (CKD) stages between best and worst post-PCN interval in those without UTI (42%, 18/43), compared to those with at least one post-PCN UTI (72%, 34/47).
Conclusions
Our study confirmed a similar renal function trend post-PCN for malignant ureteric obstruction across different demographics. It is clear that although most patients’ renal function initially improve post-PCN, the general trend for the majority of patients is to deteriorate towards pre-PCN eGFR and CKD stage values. Our data suggest that urinary tract infections play an important role in poor renal function response within six months post-PCN. Future studies should explore whether the development of UTI following PCN is an independent and modifiable risk factor for poor renal outcome.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:uct/oai:localhost:11427/31590 |
| Date | 13 March 2020 |
| Creators | De Wet, Christiaan Ernst |
| Contributors | Kaestner, Lisa-Ann |
| Publisher | Faculty of Health Sciences, Division of Urology |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Master Thesis, Masters, MMed |
| Format | application/pdf |
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