Glucose Management during Insulinoma Resection Using Real-Time Subcutaneous Continuous Glucose Monitoring

Intraoperative intermittently scanned continuous glucose monitoring in the management of patients with pancreatic insulinoma

INTRODUCTION

Insulinomas represent the most common functional pancreatic neuroendocrine tumors. Following preoperative localization, surgical excision is the curative treatment. It may be difficult to confirm a complete resection of insulinoma. We used intermittently scanned continuous glucose monitoring (isCGM) to record the fluctuation of interstitial glucose throughout surgery to help verify the tumor's complete surgical excision.

MATERIALS AND METHODS

In five individuals with insulinoma undergoing laparoscopic surgery we used the isCGM system (Freestyle Libre 2 Abbott) during tumor removal in order for the surgeon to understand "in real-time" the extent of tumor removal.

RESULTS

Two patients received no preoperative treatment, while three patients received medical treatment with either lanreotide (2 patients) or diazoxide (1 patient). In the non-treated patients, following tumor resection, there was a rapid interstitial glucose increase along with stabilized glucose levels thoroughly documented by intraoperative isCGM. Lanreotide treatment, on the other hand, resulted in only a minor increase in interstitial glucose. Finally, diazoxide-treated patients had a response that was intermediate between lanreotide-treated and non-treated patients.

CONCLUSION

Our findings suggest that isCGM is a useful tool to monitor the outcome of surgery during pancreatic insulinoma excision, assisting the surgical team in successfully removing the tumor. Despite the limited sample size, the results are promising, and, if validated in larger studies, they make us believe that the use of CGM systems has a definite benefit for becoming a standard in the surgical treatment of insulinomas.

Diode-pumped efficient high-power cascade Tm:GdVO4 laser simultaneously operating at ∼2 μm and ∼2.3 μm

The laser diode (LD)-pumped efficient high-power cascade Tm:GdVO4 laser simultaneously operating on the 3F4 → 3H6 (at ∼2 μm) and 3H4 → 3H5 (at ∼2.3 μm) Tm3+ transition was first reported in this paper. The cascade Tm:GdVO4 laser generated a maximum total continuous-wave (CW) laser output power of 8.42 W with a slope efficiency of 40%, out of which the maximum ∼2.3 μm CW laser output power was 2.88 W with a slope efficiency of 14%. To our knowledge, 2.88 W is the highest CW laser output power amongst the LD-CW-pumped ∼2.3 μm Tm3+-doped lasers reported so far.

Cascade lasing at ∼2 μm and ∼2.3 μm in a diode-pumped Tm:YVO4 laser

We report on the cascade continuous-wave operation of a diode-pumped Tm:YVO₄ laser on the ³F₄ → ³H₆ (at ∼2 μm) and ³H₄ → ³H₅ (at ∼2.3 μm) Tm³⁺ transitions. Pumped with a fiber-coupled spatially multimode 794 nm AlGaAs laser diode, the 1.5 at.% Tm:YVO₄ laser yielded a maximum total output power of 6.09 W with a slope efficiency of 35.7% out of which the ³H₄ → ³H₅ laser emission corresponded to 1.15 W at 2291-2295 and 2362-2371 nm with a slope efficiency of 7.9% and a laser threshold of 6.25 W.

Insulinoma presenting as hypoglycemia during lactose tolerance testing: a case report

Background

Insulinoma is a rare functioning pancreatic endocrine tumor, typically presenting as a sporadic solitary lesion causing hypoglycemia. While these tumors can lead to marked autonomic and neuroglycopenic symptoms, the diagnosis is often delayed.

Case presentation

We present a case of a 60-year-old Caucasian man presenting with a 1-year history of progressive episodic confusion and an unexpected finding of symptomatic hypoglycemia during a lactose tolerance test. Further inquiry revealed an 8-year history of more subtle episodic neuroglycopenic symptoms preceding his presentation. After additional biochemical testing suggested a diagnosis of insulinoma, abdominal imaging was performed and revealed a 1.2-cm tumor in the tail of the pancreas. Following laparoscopic resection of the tumor, the patient had complete resolution of his symptoms and maintained normal glucose levels.

Conclusions

The clinical presentation of functioning pancreatic neuroendocrine tumors can be subtle and nonspecific. As such, clinicians should remain vigilant for insulinoma when symptomatic hypoglycemia is present. To our knowledge, this is the first report of an insulinoma found after hypoglycemia was detected during lactose tolerance testing.