Lee L. Swanstrom

Background: Enlarged cystic kidneys, as measured by total kidney volume (TKV), highly correlate with “mass effect” symptoms and predict early loss of kidney function in autosomal dominant polycystic kidney disease (ADPKD). Sclerotherapy of large kidney cysts can reduce TKV and the associated mass effect. This study assessed if sodium tetradecyl sulfate sclerotherapy provides effective volume reduction in ADPKD and investigated its mechanism of action using porcine bladder models. Methods: Retrospective review of 567 cysts treated with sodium tetradecyl sulfate in 306 patients between November 2014 and August 2022 was performed. Cysts were treated with single-stage (cyst7cm) sclerotherapy. TKV and treated renal cyst volumes were calculated on MRI to assess response. Renal function and tolvaptan data was collected. To investigate the action of sodium tetradecyl sulfate, porcine bladder models were evaluated using confocal laser endomicroscopy and formalin-fixed hematoxylin and eosin staining, comparing treated and control tissues. Results: 495 cysts had adequate MRI follow-up to determine volume response; 99% of cysts showed volume reduction on first follow-up (mean 162 days), with mean reduction of 197cm ³ (88 ±16%). Larger cysts showed greater volume reduction. Long-term, 80% cysts showed further volume reduction while 18% were stable compared to the first follow-up MRI (mean 1359 days), indicating a sustained response. Mean TKV and mean height-adjusted TKV decreased by 371cm ³ and 224cm ³ respectively at the final follow-up. Serum creatinine increased by 30.5 ±82.6 mg/dL and eGFR decreased by 8.6 ±14.92 mL/min/1.73m ² at mean follow-up 1460 days. In the porcine bladder models, sodium tetradecyl sulfate showed near complete denudation of the epithelium, superficial inflammatory changes and vascular congestion in the lamina propria without deeper mural injury. Conclusions: Sodium tetradecyl sulfate sclerotherapy provides effective, sustained long-term volume reduction in treated renal cysts and TKV in ADPKD, and is associated with reduced renal function decline.

Background: Pancreatic cancers can involve large blood vessels early, making complete resection technically challenging or impossible. A minimally invasive treatment that clears vessels from encasing tumours could potentially enable curative surgery. We hypothesise that Endovascular Photo-activated Ablation (EPA) of perivascular tumour tissue can create a necrotic zone free of viable tumour between cancer and blood vessels, through which the tumour could be resected. Methods: A dose escalation study was conducted in the normal porcine model (n = 7). Under general anaesthesia, the animals were given a photo-activated drug and photo-activation was provided by a prototype balloon catheter, positioned in a major blood vessel within the pancreas, under angiographic guidance. Contrast-enhanced CT scans were undertaken prior to and 1, 2, or 7 days following ablation. The animals were euthanised and the exposed tissue excised en bloc for histological examination. Results: Five animals were euthanised after 2 days. On post-mortem, the histology confirmed necrotic pancreas in the perivascular zone, which increased from zero to 15 mm around the treated vessel, for increasing drug doses. Treated arteries showed necrotising arteritis, without evidence of perforation or obstruction during the observation period, although one animal was euthanised at 1 day, due to technical endovascular device issues and obstruction. The lowest-dose animal euthanised at 7 days showed no lesions on pathology. Conclusions: These proof-of-concept results demonstrate that EPA can produce pancreatic perivascular necrosis in a large animal model. In a pancreatic cancer abutting a major blood vessel, this procedure may be able to create a zone free of viable tumour, potentially rendering these cancers operable, while preserving vessel integrity. These findings support further research activities towards clinical translation.

Objective: To evaluate the safety and efficacy of endoscopic ultrasound-guided gallbladder drainage (EUS-GBD) using a lumen-apposing metal stent (LAMS). Background: For patients with acute cholecystitis who are poor surgical candidates, EUS-GBD using a LAMS is an important treatment alternative to percutaneous gallbladder drainage. Methods: We conducted a regulatory-compliant, prospective multicenter trial at 7 tertiary referral centers in the United States of America and Belgium. Thirty consecutive patients with mild or moderate acute cholecystitis who were not candidates for cholecystectomy were enrolled between September 2019 and August 2021. Eligible patients had a LAMS placed transmurally with 30 to 60-day indwell if removal was clinically indicated, and 30-day follow-up post-LAMS removal. Endpoints included days until acute cholecystitis resolution, reintervention rate, acute cholecystitis recurrence rate, and procedure-related adverse events (AEs). Results: Technical success was 93.3% (28/30) for LAMS placement and 100% for LAMS removal in 19 patients for whom removal was attempted. Five (16.7%) patients required reintervention. Mean time to acute cholecystitis resolution was 1.6±1.5 days. Acute cholecystitis symptoms recurred in 10.0% (3/30) after LAMS removal. Five (16.7%) patients died from unrelated causes. Procedure-related AEs were reported to the FDA in 30.0% (9/30) of patients, including one fatal event 21 days after LAMS removal; however, no AEs were causally related to the LAMS. Conclusions: For selected patients with acute cholecystitis who are at elevated surgical risk, EUS-GBD with LAMS is an alternative to percutaneous gallbladder drainage. It has high technical and clinical success, with low recurrence and an acceptable AE rate. Clinicaltrials.gov, Number: NCT03767881.

Background To prove feasibility of multimodal and temporal fusion of laparoscopic images with preoperative computed tomography scans for a real-time in vivo-targeted lymph node (TLN) detection during minimally invasive pelvic lymphadenectomy and to validate and enable such guidance for safe and accurate sentinel lymph node dissection, including anatomical landmarks in an experimental model. Methods A measurement campaign determined the most accurate tracking system (UR5-Cobot versus NDI Polaris). The subsequent interventions on two pigs consisted of an identification of artificial TLN and anatomical landmarks without and with augmented reality (AR) assistance. The AR overlay on target structures was quantitatively evaluated. The clinical relevance of our system was assessed via a questionnaire completed by experienced and trainee surgeons. Results An AR-based robotic assistance system that performed real-time multimodal and temporal fusion of laparoscopic images with preoperative medical images was developed and tested. It enabled the detection of TLN and their surrounding anatomical structures during pelvic lymphadenectomy. Accuracy of the CT overlay was > 90%, with overflow rates < 6%. When comparing AR to direct vision, we found that scores were significatively higher in AR for all target structures. AR aided both experienced surgeons and trainees, whether it was for TLN, ureter, or vessel identification. Conclusion This computer-assisted system was reliable, safe, and accurate, and the present achievements represent a first step toward a clinical study. Graphical abstract

Background: Per-oral endoscopic myotomy (POEM) is a valuable tool for the treatment of foregut motility disorders. Hands-on courses are often utilized at the initial means of training in POEM. Whether such training is sufficient to allow individuals to launch an independent practice in POEM is unknown. The purpose of this study was to evaluate the successes and barriers of implementing a POEM practice after attending a hands-on course. Methods: We evaluated participants of a 2-day focused POEM training course. All participants of the course were sent a survey to assess their endoscopic practice before and after the course, concentrating on their ability to implement POEM after returning to their home institution. Results: Between 2012 and 2017, 11 POEM courses were held at our institution, with a total of 102 trainees. Fifty-five individuals responded to our survey (53.9%), most of whom were general surgeons who were already doing some therapeutic endoscopy but had not previously performed POEM. More than half (58.2%) were able to institute a POEM practice at their home institution after the course. Those that were successful in starting a POEM practice were more often those with previous advanced endoscopic experience (90.3%). Success was assisted by high rates of additional explant laboratories (43.6%) and in-person proctoring (52.4%) after completing the course. Those that did not start a POEM practice sited lack of institutional support as the main barrier, followed by problems with insurance approval, and lack of referral volume. Conclusion: Despite the complexity of the POEM procedure, a focused hands-on POEM training course is associated with a high rate of implementation of an independent POEM practice, particularly in individuals with previous advanced endoscopic experience. The largest barriers to POEM adoption are not technical factors, but rather are related to institutional and insurance factors.