I. Siddiqui

High-Frequency Irreversible Electroporation: Safety and Efficacy of Next-Generation Irreversible Electroporation Adjacent to Critical Hepatic Structures:

Irreversible electroporation (IRE) is a nonthermal ablation modality employed to induce in situ tissue-cell death. This study sought to evaluate the efficacy of a novel high-frequency IRE (H-FIRE) system to perform hepatic ablations across, or adjacent to, critical vascular and biliary structures. Using ultrasound guidance H-FIRE electrodes were placed across, or adjacent to, portal pedicels, hepatic veins, or the gall bladder in a porcine model. H-FIRE pulses were delivered (2250 V, 2-5-2 pulse configuration) in the absence of cardiac synchronization or intraoperative paralytics. Six hours after H-FIRE the liver was resected and analyzed. Nine ablations were performed in 3 separate experimental groups (major vessels straddled by electrodes, electrodes placed adjacent to major vessels, electrodes placed adjacent to gall bladder). Average ablation time was 290 ± 63 seconds. No electrocardiogram abnormalities or changes in vital signs were observed during H-FIRE. At necropsy, no vascular damage, coagulated-thermally desiccated blood vessels, or perforated biliary structures were noted. Histologically, H-FIRE demonstrated effective tissue ablation and uniform induction of apoptotic cell death in the parenchyma independent of vascular or biliary structure location. Detailed microscopic analysis revealed minor endothelial damage within areas subjected to H-FIRE, particularly in regions proximal to electrode insertion. These data indicate H-FIRE is a novel means to perform rapid, reproducible IRE in liver tissue while preserving gross vascular/biliary architecture. These characteristics raise the potential for long-term survival studies to test the viability of this technology toward clinical use to target tumors not amenable to thermal ablation or resection.

Robotic pancreas drainage procedure for chronic pancreatitis: robotic lateral pancreaticojejunostomy (Puestow procedure)

Lateral pancreaticojejunostomy (LPJ), also known as the Puestow procedure, is a complex surgical procedure reserved for patients with refractory chronic pancreatitis (CP) and a dilated pancreatic duct. Traditionally, this operation is performed through an open incision, however, recent advancements in minimally invasive techniques have made it possible to perform the surgery using laparoscopic and robotic techniques with comparable safety. Though we do not have enough data yet to prove superiority of one over the other, the robotic approach appears to have an advantage over the laparoscopic technique in better visualization through 3-dimensional (3D) imaging and availability of wristed instruments for more precise actions, which may translate into superior outcomes. This paper is a description of our technique for robotic LPJ in patients with refractory CP. Important principles of patient selection, preoperative workup, surgical technique and post-operative management are discussed. A short video with a case presentation and highlights of the important steps of the surgery is included.

Hyperspectral imaging based on compressive sensing to determine cancer margins in human pancreatic tissue ex vivo

Pancreatic cancer is the fourth leading cause of cancer death in the US. Currently, surgery is the only treatment that offers a chance of cure, however, accurately identifying tumor margins in real-time is difficult. Research has demonstrated that optical spectroscopy can be used to distinguish between healthy and diseased tissue. The design of a single-pixel imaging system for cancer detection is discussed. The system differentiates between healthy and diseased tissue based on differences in the optical reflectance spectra of these regions. In this study, pancreatic tissue samples from 6 patients undergoing Whipple procedures are imaged with the system (total number of tissue sample imaged was N=11). Regions of healthy and unhealthy tissue are determined based on SAM analysis of these spectral images. Hyperspectral imaging results are then compared to white light imaging and histological analysis. Cancerous regions were clearly visible in the hyperspectral images. Margins determined via spectral imaging were in good agreement with margins identified by histology, indicating that hyperspectral imaging system can differentiate between healthy and diseased tissue. After imaging the system was able to detect cancerous regions with a sensitivity of 74.50±5.89% and a specificity of 75.53±10.81%. Possible applications of this imaging system include determination of tumor margins during surgery/biopsy and assistance with cancer diagnosis and staging.

High frequency irreversible electroporation (H-FIRE) as a novel method of targeted cell death.

277 Background: Irreversible electroporation unlike ablation is excellent in inducing cell death via apoptosis. It, however, has disadvantages of electrical conduction via cardiac and nervous tissue. This results in requiring cardiac monitoring and general anesthesia and paralytics while performing electroporation. We hypothesized a novel high-frequency IRE (H-FIRE) system employing ultra-short bipolar pulses would obviate the need for cardiac synchronization and paralytics while maintaining measurable effect on cell death. Methods: Female swine (55-65Kg) were used. Two H-FIRE electrodes were inserted into the liver (1.5-cm spacing). In the absence of paralytics H-FIRE pulses were delivered (2250V, 2-5-2 pulse configuration) at different on times (100 vs. 200μs) or number of pulses (100 vs. 300). Next electrodes were placed across major hepatic vascular structures and H-FIRE performed. At conclusion tissue was resected and analyzed histologically. Results: 24 H-FIREs were performed (mean ablation time 275...