Time-dependent image changes after ethanol injection into the pancreas: an experimental study using a porcine model

A single-center experience on endoscopic ultrasonography-guided ethanol ablation of insulinomas

BACKGROUND/OBJECTIVES

As the most frequent functional pancreatic neuroendocrine tumor, insulinomas may cause a plethora of symptoms and severe impairment in the living of patients by endogenous hyperinsulinemia and subsequent hypoglycemia. Surgery has been regarded as the first choice although a high risk of complications. Ethanol ablation is a promising non-surgical option that could achieve tumor shrinking in a short-term period. But the impact of symptom control and the long-term efficacy lack sufficient and good-quality evidence.

METHODS

A total number of 14 endoscopic ultrasonography-guided ethanol ablations were performed in 9 patients between September 2016 and September 2018 in Peking Union Medical College Hospital. The data were collected and prospectively analyzed.

RESULTS

The follow-up duration ranged from 21 to 1567 days in 9 patients, with a median of 994 days. 4 patients were free from relapse during a median follow-up of 1108 days (range: 994-1567 days). In 5 patients who suffered relapses, the median duration with symptom relief after the first ablation was 128 days (range: 13-393 days). If only repeated ablation was taken into consideration, the median duration with symptom relief was 26 days (range: 1-516 days). No complications happened during the procedures. The severe complication rate after the first ablation was 0.0% (0/9), compared to 7.14% (1/14) if each procedure was counted separately. The only severe complication documented was acute pancreatitis which was completely relieved after symptomatic treatment.

CONCLUSIONS

For patients who are not suitable for surgical resections, endoscopic ultrasonography-guided ethanol ablation of insulinomas could be an effective and safe alternative to relieve symptoms of hypoglycemia.

Efficacy and safety of scheduled early endoscopic ultrasonography-guided ethanol reinjection for patients with pancreatic neuroendocrine tumors: Prospective pilot study

Endoscopic ultrasonography (EUS)-guided ethanol injection was recently proposed for treatment of patients with small pancreatic neuroendocrine tumors (p-NET); however, tips on how to carry out safe and effective procedures are unclear. We launched a pilot study for scheduled early EUS-guided ethanol reinjection for small p-NET. Major eligibility criteria were presence of pathologically diagnosed grade (G) 1 or G2, tumor size ≤2 cm and being a poor or rejected candidate for surgery. For the treatment, we used a 25-gauge needle and pure ethanol. Contrast-enhanced computed tomography (CE-CT) was carried out on postoperative day 3, and if enhanced areas of the tumor were still apparent, an additional session was scheduled during the same hospitalization period. Primary endpoint was complete ablation rate at 1 month after treatment, and secondary endpoint was procedure-related adverse events. A total of five patients were treated. Median size of the tumor was 10 (range: 7-14) mm. Of the five patients, three underwent an additional session. Median volume of ethanol injection per session was 0.8 (range: 0.3-1.0) mL, and the total was 1.0 (0.9-1.8) mL. Complete ablation was achieved in four of the five tumors (80%) with no adverse events. During 1 year of follow up, none of the patients reported any procedure-related adverse events, and no recurrence of tumor. Scheduled early EUS-guided ethanol reinjection appears to be safe and effective for treating small p-NET (UMIN number: 000018834).