Locally advanced pancreatic cancer (Stage 3) is defined by encasement or abutment of vital venous and arterial structures. Irreversible electroporation (IRE) represents an effective local non-thermal ablation modality for treatment of solid tumors involving critical vascular and biliary structures. Electroporation creates pores in the cell membrane and disrupts the ionic gradients while sparing the extracellular matrix, resulting in preservation of blood vessel and biliary scaffolding.
DOI: http://dx.doi.org/10.17797/yonbav6fdz
Editor Recruited by: Jeffrey B. Matthews
For an open technique, after induction of general endotracheal anesthesia with full muscle relaxation, an upper midline incision should be made from 4-6 cm inferior to the xiphoid to the umbilicus. After thorough exploration, a Thompson retractor should be placed with one blade at the apex of the upper midline incision and two bladder blades retracting laterally. Intraoperative ultrasound (IOUS) should be performed of the liver to assess for metastases as well as of the pancreatic tumor to examine its three dimensional size. Additionally, a transgastric ultrasound should be used to ensure unresectability of the tumor.3 The lesser sac should then be opened and target sites chosen for needle placement. Needles should then be inserted parallel to each other under continuous ultrasound monitoring. This ensures needles are placed so as to 1) avoid injury to vital structures and 2) result in maximal tumor killing and adequate ablation margins. After ensuring muscle paralysis and pain control, a test pulse at 10% planned energy should be delivered to asses that adequate current is achieved. 90 direct current, high-voltage (pulses of 100 microseconds each should then be delivered in groups of 10 with a pulse interval of 250 milliseconds. Subsequently, electroporation current should be passed between electrodes to assess for a change in tissue resistivity. This validates that sufficient electroporation has occurred. Finally, ultrasound should be used to confirm ablation and to assess vascular flow and patency.
IRE is indicated for locally advanced pancreatic cancer, defined as encasement of the celiac axis, superior mesenteric artery, or both.1 IRE is indicated for treatment of tumors occluding the superior mesenteric vein (SMV)-portal vein confluence.
Absolute contraindications include tumor size >5 cm, metastatic disease, increase in tumor diameter by >30% while undergoing pre-operative chemotherapy and/or radiation, and uncontrolled angina or inducible ischemia on cardiac stress test. Relative contraindications include atrial fibrillation, tumor diameter >3.5 cm, poor functional status (Karnofsky Performance Status <80%), inability to tolerate general endotracheal anesthesia.2,3
IRE can be performed via an open, laparoscopic, or percutaneous approach. All cases require general endotracheal anesthesia with complete muscle relaxation/chemical paralysis. Patients must undergo continuous EKG monitoring, as the IRE device delivers pulses in synchronization with cardiac electrical impulses.4 Intraoperative ultrasound is required for tumor dimensional analysis as well as for probe placement. Monopolar electrode probes consist of a 19 gauge needle with an adjustable active length and an echogenic surface. NanoKnife™ (AngioDynamics®), Queensbury, USA Energy output -- 3 kV, 50-amp maximum energy output) represents the most commonly used IRE generator.2,3
In addition to routine laboratory analyses for patients diagnosed with pancreatic cancer, (e.g. CBC, CMP, PT/INR, PTT, CA 19-9), recommended pre-operative workup includes complete staging of pancreatic adenocarcinoma including three phase thin cut pancreatic protocol computed tomography (CT) or dynamic MRI with diagnostic laparoscopy to rule out radiologically undetectable occult metastases. Patients being considered for IRE usually undergo 3-4 months of pre-operative chemotherapy with or without external beam radiation therapy (XRT) and are precluded from IRE if they demonstrate significant tumor growth during this period (see above).2
N/A
Advantages to IRE compared with thermal ablative modalities include high tissue selectivity, sharply defined irreversible ablation zone margins with decreased thermal spread and resultant collateral tissue damage, and preservation of critical vascular structures.1,2 Disadvantages include requirement for multi-probe arrays, increased technical difficulty, and decreased efficacy in treating tumors >3.5 cm in anterior-posterior dimension, inability to utilize in patients with metallic pancreaticobiliary stents, and requirement for complete intra-operative paralysis.1
Procedure related complications include, but are not limited to, fever, bleeding, cardiac dysrhythmia and/or arrest, portal vein thrombosis, deep venous thrombosis, and post-procedural ileus.2,3,5,6
N/A
N/A
1. Varadhachary GR, Tamm EP, Abbruzzese JL, et al. Borderline resectable pancreatic cancer: definitions, management, and role of preoperative therapy. Annals of surgical oncology. Aug 2006;13(8):1035-1046.
2. Martin RC, 2nd. Irreversible electroporation of locally advanced pancreatic neck/body adenocarcinoma. Journal of gastrointestinal oncology. Jun 2015;6(3):329-335.
3. Martin RC, 2nd, McFarland K, Ellis S, Velanovich V. Irreversible electroporation therapy in the management of locally advanced pancreatic adenocarcinoma. Journal of the American College of Surgeons. Sep 2012;215(3):361-369.
4. Nielsen K, Scheffer HJ, Vieveen JM, et al. Anaesthetic management during open and percutaneous irreversible electroporation. British journal of anaesthesia. Dec 2014;113(6):985-992.
5. Cannon R, Ellis S, Hayes D, Narayanan G, Martin RC. Safety and early efficacy of irreversible electroporation for hepatic tumors in proximity to vital structures. J Surg Oncol. Apr 2013;107(5):544-549.
6. Martin RC, 2nd, McFarland K, Ellis S, Velanovich V. Irreversible electroporation in locally advanced pancreatic cancer: potential improved overall survival. Annals of surgical oncology. Dec 2013;20 Suppl 3:S443-449.
Review Irreversible Electroporation for Treatment of Locally Advanced Pancreatic Cancer. Cancel reply
Related Videos
Authors
Carol Li, MD1*, Apoorva T. Ramaswamy, MD1*, Sallie M. Long, MD 1 , Alexander Chern, MD 1 , Sei Chung, MD 1 , Brendon Stiles, MD 2 , Andrew B. Tassler, MD 1
1Department of Otolaryngology-Head and Neck Surgery, Weill Cornell Medicine, New York, NY 2Department of Cardiothoracic Surgery, Weill Cornell Medicine, New York, NY
*Co-First authors
Overview
The COVID-19 pandemic is an unprecedented global healthcare emergency. The need for prolonged invasive ventilation is common amid this outbreak. Despite initial data suggesting high mortality rates among those requiring intubation, United States data suggests better outcomes for those requiring invasive ventilation. Thus, many of these patients requiring prolonged ventilation have become candidates for tracheotomy. Considered aerosol generating procedures (AGP), tracheotomies performed on COVID-19 patients theoretically put health care workers at high risk for contracting the virus. In this video, we present our institution’s multidisciplinary team-based methodology for the safe performance of tracheotomies on COVID-19 patients. During the month of April 2020, 32 tracheotomies were performed in this manner with no documented cases of COVID-19 transmission with nasopharyngeal swab and antibody testing among the surgical and anesthesia team.
Procedure Details
The patient is positioned with a shoulder roll to place the neck in extension. The neck is prepped and draped in a sterile fashion with a clear plastic drape across the jawline extending superiorly to cover the head. An institutional timeout is performed. The patient is pre-oxygenated on 100% FiO2. A 2-cm vertical incision is made extending inferiorly from the lower border of the palpated cricoid cartilage. Subcutaneous tissues and strap muscles are divided in the midline. When the thyroid isthmus is encountered, it is either retracted out of the field or divided using electrocautery. The remaining fascia is then cleared off the anterior face of the trachea.
Prior to airway entry, the anesthesiologist pauses all ventilation and turns off oxygen flow. The endotracheal tube (ETT) is advanced distally past the planned tracheotomy incision, without deflating the cuff, if possible. If necessary, the endotracheal cuff is deflated partially to advance the tube, with immediate reinflation once in position. The surgical team then creates a tracheotomy using cold steel instruments. The cricoid hook is placed in the tracheotomy incision and retracted superiorly for exposure of the lumen. The tube is withdrawn under direct visual guidance, without deflating the endotracheal cuff if possible. The tracheotomy tube is placed, and to minimize aerosolization of respiratory secretions, the cuff is inflated prior to re-initiation of ventilation. The tracheotomy tube is then sewn to the skin using 2-0 prolene suture. A total of five simple stitches are placed around the tube to prevent accidental decannulation.
Indications/Contraindications
Candidacy for tracheotomy was determined on a case by case basis with consideration for progression of ventilator weaning, viral load, and overall prognosis. All patients who underwent tracheotomy were intubated prior to the surgery for a minimum of 14 days, able to tolerate a 90-second period of apnea without significant desaturation or hemodynamic instability, and expected to recover. Optimal ventilator settings included FiO2 = 50% and PEEP = 10 cm H20.
Instrumentation
A standard tracheostomy instrument tray was utilized, including the following: tonsil dissector, DeBakey forceps, right-angle retractors, cricoid hook, and tracheal dilator. Bovie electrocautery was also utilized.
Setup
Please refer to the diagrams depicted in the accompanying video.
Preoperative Workup
An apnea test was performed for 90 seconds to ensure that the patient had adequate reserve. Ventilator settings were optimized. If possible, systemic anticoagulation was paused.
Anatomy and Landmarks
Important landmarks include the thyroid cartilage, cricoid cartilage, and sternal notch. A high-riding innominate artery can be detected on imaging and with palpation during the surgery.
Advantages/Disadvantages
Given the unique benefits of tracheotomy in avoiding the laryngeal trauma associated with prolonged intubation, decreased dead space, and ease of trialing patients off of the ventilator, there is high motivation to perform tracheotomies in COVID-19 patients requiring intubation and prolonged mechanical ventilation. Major disadvantages include the risk of virus transmission among the surgical and anesthesia team.
Complications/Risks
Short-term complications include bleeding and infection, such as peristomal cellulitis. Long-term complications of tracheostomy include cartilage destruction or deformity, granulation tissue formation, and superficial scarring.
References: N/A
As technique and technology have evolved in the modern age, surgical emphasis has shifted steadily towards minimally invasive alternatives. In colon surgery, laparoscopy has been shown to improve multiple outcome metrics, including reductions in post-operative morbidity, pain, and hospital length of stay, while maintaining surgical success rates. Unfortunately, despite the minimally invasive approach, elective laparoscopic sigmoidectomy typically requires an abdominal wall extraction site, leaving a large incision in addition to the laparoscopic port sites. It also utilizes three different types of intestinal staplers, leading to an anastomosis that may have multiple intersecting staple lines, thereby potentially influencing the anastomotic integrity, as well as increasing procedural costs substantially.
We present a case of a totally robotic sigmoidectomy utilizing a single stapler technique and natural orifice specimen extraction in a patient with multiple, severe, recurrent episodes of sigmoid diverticulitis over a 2-year period.
Disclosure/ Conflict of interest: The authors whose names are listed above certify that they have NO affiliations with or involvement in any organisation or entity with any financial interest (such as honoraria; educational grants; participation in speakers ’bureaus; membership, employment, consultancies, stock ownership, or other equity interest; and expert testimony or patent-licensing arrangements), or non-financial interest (such as personal or professional relationships, affiliations, knowledge or beliefs) in the subject matter or materials discussed in this manuscript.
Review Irreversible Electroporation for Treatment of Locally Advanced Pancreatic Cancer.