Pannala, Rahul

Abstract Accurate endoscopic marking of suspicious lesions and polyps is essential for the effective surgical management of gastrointestinal (GI) diseases, including colorectal cancer and inflammatory bowel disease. Currently, lesion localization relies on submucosal injection of a carbon-based tattoo ink; however, this ink exhibits extensive tissue diffusion and extravasation, leading to poor spatial fidelity, compromised precision, and risk for fibrotic responses. Given the need for contrast relative to endoscopic white light and biocompatibility, we report here the design and evaluation of melanin-inspired nanoparticle tattoo (MINT) inks, formulated from synthetic melanin nanoparticles and biopolymer-encapsulated synthetic melanin. MINT inks are designed to be durable, high-contrast, easily injectable, and colloidally stable for at least 2 months and to elicit minimal macrophage-mediated inflammatory responses in vitro. In live porcine colon studies, submucosal injection of MINT inks resulted in highly localized tattoos with minimal lateral spread over 9 weeks of follow-up, which is a significant advantage over the extensive diffusion observed with clinical carbon ink. MINT tattoo markings were distinctly visible from both mucosal and serosal surfaces of the intestine and enabled reproducible multipoint and quadrant-based marking, which enhanced spatial orientation. Collectively, these findings demonstrate that MINT inks are biocompatible and capable of providing precise, long-lasting, high-contrast marking of lesions in the colon. By overcoming the limitations of conventional carbon-particle-based tattoos, MINT inks represent a promising next-generation contrast agent for improving endoscopic localization and surgical outcomes in GI diseases.

ABSTRACT Background Post‐pancreatectomy exocrine insufficiency is common after resection for pancreatic cancer and requires pancreatic enzyme replacement therapy (PERT). We sought to determine the out‐of‐pocket cost of PERT and the association between PERT and survival. Methods The SEER‐linked Medicare database was queried for patients with pancreatic cancer who underwent pancreaticoduodenectomy (PD) or distal pancreatectomy (DP) from 2010 to 2019. Cumulative out‐of‐pocket costs were calculated and stratified by procedure and radiation. Results 11,854 Medicare beneficiaries with resected pancreatic cancer were identified, 4,653 (39%) required PERT and 7,201 (61%) did not. Median age was 73.0, 50.6% were female and 83.6% White. 25.9% underwent DP and 74.1% underwent PD; 7% received neoadjuvant radiation while 23.5% received adjuvant radiation. Logistic regression demonstrated that female sex (OR 1.25, 95% CI 1.16‐1.35, p < 0.001), neoadjuvant radiation (OR 1.93, 95% CI 1.67‐2.24, p < 0.001), and PD (OR 2.45, 95% CI 2.23‐2.7, p < 0.001) were risk factors for requiring PERT. Patients without subsidies who underwent DP paid a cumulative $4,736 out‐of‐pocket for PERT after 5 years, those who underwent PD paid $5,601 out‐of‐pocket. Conclusions Nearly 40% of Medicare beneficiaries took PERT after resection for pancreatic cancer and paid thousands in out‐of‐pocket costs. While a conservative estimate, these findings highlight the importance of addressing this financial burden to patients.

Acute cholecystitis affects ∼200,000 individuals annually in the United States, with laparoscopic cholecystectomy as the gold standard treatment. However, in high-risk surgical candidates, alternative drainage methods are necessary. Percutaneous transhepatic gallbladder drainage (PT-GBD) has traditionally served as the primary alternative intervention, offering rapid decompression, but is limited by a negative impact on the patient’s quality of life, the risk of long-term or even permanent tube placement, adverse events, and high recurrence rates. Endoscopic approaches, such as endoscopic transpapillary gallbladder drainage (ET-GBD) and, more recently, endoscopic ultrasound-guided gallbladder drainage (EUS-GBD), have emerged as viable alternatives to PT-GBD. EUS-GBD, first introduced in 2007, offers technical and clinical outcomes comparable to PT-GBD with fewer adverse events, shorter hospital stays, and lower rates of recurrence. The introduction of lumen-apposing metal stents (LAMS) has revolutionized EUS-GBD, simplifying deployment and enabling subsequent internal gallbladder access, which allows additional interventions such as cholecystoscopy and stone removal. EUS-GBD is now supported by international guidelines, and 1 device has achieved FDA approval for the management of acute cholecystitis in nonsurgical candidates. Proper patient selection is essential, guided by multidisciplinary evaluation, with EUS-GBD contraindicated in specific scenarios such as gallbladder perforation, coagulopathy, and large-volume ascites. Technical considerations include choice of access site (transgastric versus transduodenal), stent type, and procedural route [direct (freehand) or wire-guided]. Postprocedural care and stent management remain variable and nonstandardized. Emerging data suggest that interval cholecystectomy can still be performed safely after EUS-GBD. As adoption of EUS-GBD with LAMS expands, structured training and standardization of practice are crucial to optimizing outcomes.

e16017 Background: Pancreatic ductal adenocarcinoma (PDAC) is the most common form of pancreatic cancer and remains one of the deadliest malignancies worldwide, largely due to late-stage diagnosis. Early-stage PDAC is frequently asymptomatic, limiting opportunities for timely detection and intervention. We aimed to develop prognostic models using routinely acquired pre-diagnostic clinical data to identify individuals at high risk for PDAC prior to clinical manifestation. Methods: We conducted a retrospective study of patients treated at Mayo Clinic sites in Rochester, MN; Phoenix, AZ; and Jacksonville, FL between January 2011 and February 2023. The cohort included 1,151 patients with PDAC and 3,745 noncancer controls. CT scans were standardized to axial abdominal acquisitions with slice thickness between 0.8–3.0 mm. Radiology reports were de-identified, normalized, and parsed into structured sections (Indications, Findings, Impression), with an additional pancreas-specific section aggregating pancreas-related sentences. Demographic and clinical variables, e.g., age, sex, race, etc., were encoded using a templated sentence representation. All textual inputs were embedded using a Sentence-BERT model. A multimodal deep learning survival model was developed to integrate CT imaging, radiology report embeddings, and demographic features. The model was trained using a negative log-likelihood loss to estimate patient-specific PDAC risk scores. Model performance was assessed using the concordance index (C-index). Internal validation included patients from MN and AZ sites, while external validation used the FL cohort. Results: We evaluated unimodal (imaging, text, and demographics) and multimodal inputs. Fusion of imaging, radiology report, and demographic features achieved the highest performance, with internal and external validation C-indices of 0.885 (95% CI, 0.856–0.908) and 0.751 (95% CI, 0.719–0.783), respectively. Subgroup analysis by tumor location demonstrated differential performance. For pancreatic head tumors, internal and external C-indices were 0.916 (95% CI, 0.841–0.960) and 0.778 (95% CI, 0.730–0.823). For pancreatic body tumors, C-indices were 0.954 (95% CI, 0.897–0.997) internally and 0.929 (95% CI, 0.897–0.953) externally. For pancreatic tail tumors, internal and external C-indices were 0.903 (95% CI, 0.830–0.974) and 0.789 (95% CI, 0.689–0.874). Conclusions: A multimodal deep survival model leveraging pre-diagnostic CT imaging, radiology report embeddings, and demographic data can effectively identify individuals at high risk for PDAC prior to clinical diagnosis. Differences in performance were observed across pancreatic head, body, and tail tumors. This approach highlights the potential of opportunistic cancer risk stratification from routine imaging to enable earlier detection and targeted intervention strategies.