Delivery of extracorporeal shock wave lithotripsy (ESWL) for pancreaticolithiasis by gastroenterologists rather than the more traditional urologist route resulted in higher procedure volumes, more shocks per session, and improved duct clearance, a small retrospective study found.
The single-center study of 79 patients also observed more same-day endoscopic retrograde cholangiopancreatography (ERCP) and fewer post-procedure hospitalizations among those treated by gastroenterologists, according to B. Joseph Elmunzer, MD, a gastroenterologist at the Medical University of South Carolina in Charleston, and colleagues.
No differences were seen in case complexity, and wait times for ESWL were not significantly increased, they wrote in Clinical Gastroenterology and Hepatology.
For their study, the researchers looked at outcomes for 61 patients given ESWL by gastroenterologists from 2017 to 2019, and 18 patients treated by urologists from 2014 to 2017. For gastroenterologists versus urologists, respectively, the following differences were observed:
- Mean number of shocks per session: 4,341 vs 3,117 (P<0.001)
- Same-day ESWL and ERCP: 65.6% vs 5.6% (P<0.001)
- Partial or complete duct clearance on follow-up imaging: 71% vs 44% (P=0.04)
- Post-procedure hospitalizations: 14.8% vs the urology protocol-mandated 100% (P<0.001)
- Captured adverse events: 21.7% vs 16.7% (P<0.65)
- Referral time to ESWL: 49 vs 41.3 days (P=0.04)
- Second ESWL session required: 9.8% vs 16.7%
“These findings may help inform decision-making at other centers in the United States that are considering a transition to gastroenterologist-directed ESWL,” the research team wrote.
Elmunzer and co-authors noted that ESWL was initially developed to treat urinary tract stones but was co-opted in the late 1980s to treat pancreaticolithiasis. In comparison with ERCP alone, ESWL appears to be associated with a decreased rate of hospitalization for chronic pancreatitis, and ESWL is guideline-recommended for clearance of main pancreatic duct stones larger than 5 mm.
The researchers undertook the comparative study to see whether gastroenterologists were willing to take on more challenging ESWL cases than urologists (complexity of medical illness and/or chronic pancreatitis stone burden) and whether transitioning to gastroenterologist-directed ESWL resulted in improved care processes (higher throughput, shorter time between referral and ESWL, more shocks per session, shorter time between ESWL and ERCP, and less hospitalization).
According to the authors’ anecdotal observation, “urologists tend to employ a more conservative approach to ESWL based on an increased risk of bleeding in the highly vascular genitourinary tract.” Furthermore, “gastroenterologists’ familiarity with the disease process as well as the capabilities and limitations of ERCP may allow a more tailored (and perhaps effective) ESWL approach.”
In addition, familiarity with ERCP-related adverse events may allow more efficient rescue from serious ESWL-associated complications, while the ability to perform same-session intra-ESWL pancreatography (via ERCP or endoscopic ultrasound-guided injection) may allow improved targeting of radiolucent stones.
In agreement is gastroenterologist James Watkins, MD, of Indiana University School of Medicine in Indianapolis, where in 2000 Glen Lehman, MD, started a transition from ESWL performed by a radiologist specializing in body imaging toward gastroenterologist-delivered ESWL.
“[Lehman] predicted that the knowledge of pancreatic anatomy, and the correlation of pre-ESWL cross-sectional imaging, as well as understanding of the optimal timing for ERCP, would lead to better care for these patients, who require frequent admission to the hospital and care for pain related to chronic pancreatitis and [pancreatic duct] stone disease,” said Watkins, who was not involved in the current study.
“As in the current study, the use of a higher number of shocks per session and the understanding of the clinical course for these patients has led to a decrease in hospital admissions, as well as decreased exposure to general anesthesia and overall cost,” said Watkins.
Elmunzer and co-authors called for multicenter studies to clarify the optimal number of shocks (standardized to the potency of the ESWL generator) as well as the role of concurrent ERCP.
“Considering that any perceived benefits must be balanced against the structural, logistical, and regulatory challenges of establishing an ESWL practice in the endoscopy unit, additional data are necessary to inform decisions about more widespread adoption of GI-directed ESWL in the U.S.,” they concluded.
Mean patient age in their study was about 58 years, and more than 40% were women. There were no differences in other demographics or comorbidities between the urologist- and gastroenterologist-treated groups, or in pancreatic stone morphology, or time from referral to ESWL.
Study limitations included the small sample size, which restricted the precision of point estimates and the ability to detect anything but large differences between study groups, the authors noted. Furthermore, the retrospective nature of the study, in combination with the small patient numbers, made it impossible to address confounding and thus comparisons between study groups were not adjusted.
The capture of adverse events was most likely incomplete as well, because many patients present to local hospitals when they develop symptoms after ESWL or ERCP. Lastly, the study design and quality of data did not allow for comparison of patient-centered outcomes.
The authors reported no specific funding for this research.
Elmunzer had no disclosures. One co-author reported being employed by a company that provides lithotripsy services to hospitals.
Watkins disclosed no competing interests relevant to his comments.