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Sassun, Richard

0000-0001-7649-4703

Mayo Clinic

Division of Colon and Rectal Surgery, Mayo Clinic, Rochester, MN, United States.

Citations 8

Why Open Surgery Must Live: Accompanying Laparoscopy to Its Death, A Reply to Kim et al
Violante, Tommaso , Sassun, Richard , Novelli, Marco , Larson, David W. , Rottoli, Matteo , Larson, David W , Violante, Tommaso , Sassun, Richard

Annals of Surgery | September 10, 2026 | Volume: No volume available | Issue: No issue available | Pages: No page available

10.1097/sla.0000000000007224 Get It

Surgical management of small bowel adenocarcinoma in Crohn disease: a multicenter retrospective analysis
Violante, Tommaso , Ferrari, Davide, Rottoli, Matteo , Novelli, Marco, Aboelmaaty, Sara , Gomaa, Ibrahim A. , Sassun, Richard, Sileo, Annaclara , Shawki, Sherief S., Wignakumar, Anjelli , Dourado, Justin, Syed, Ajia, Wexner, Steven, Calini, Giacomo, Castagna, Giovanni , Isopi, Claudio , Holubar, Stefan, Alipouriani, Ali , Unal, Ece , Mathis, Kellie L. , Calini, Giacomo , Violante, Tommaso , Novelli, Marco , Sassun, Richard , Aboelmaaty, Sara A, Gomaa, Ibrahim , Sassun, Richard , Sileo, Annaclara , Holubar, Stefan D , Alipouriani, Ali , Mathis, Kellie L , Calini, G , Ferrari, Davide , Larson, David W. , Shawki, Sherief , Dourado, Justin , Wexner, Steven, Greco, Nicola Maria , Holubar, Stefan D.

Inflammatory Bowel Diseases | December 3, 2025 | Volume: 32 | Issue: 5 | Pages: 914-921

10.1093/ibd/izaf312 Get It

Abstract Background Patients with Crohn disease (CD) face an elevated risk of developing small bowel adenocarcinoma (SBA), a malignancy characterized by late-stage diagnosis and poor prognosis. In this study we aimed to characterize surgical management and oncologic outcomes for CD-associated SBA. Methods A retrospective review was conducted across 3 tertiary IBD centers, analyzing 99 patients with CD who underwent surgery for SBA between 1992 and 2025. Data included patient demographics, CD history, surgical details, and oncologic outcomes. Results The median time from CD diagnosis to SBA was 25 years. The SBA diagnosis was incidental in 74.8% of cases, discovered during surgery for other complications. Tumors were predominantly located in the ileum (80.8%) and showed aggressive features: 56.6% were poorly differentiated (grade 3), and 85.9% were pathologically advanced (T3/T4 on TNM staging). Nodal involvement was present in 45.5% of patients, and 18.2% had distant metastases at diagnosis. A complete (R0) resection was achieved in 90.9% of surgeries, with a 30-day morbidity rate of 26.3%. After a median follow-up of 36 months, the distant recurrence rate was 28.3%, and overall mortality was 27.3% (18.2% cancer related). Conclusion In patients with long-standing CD, SBA is typically an incidental diagnosis made at an advanced stage. While high rates of complete surgical resection are possible, the prognosis remains guarded due to aggressive tumor biology and high recurrence rates. These findings highlight a critical need for improved risk stratification to guide surveillance and for the development of evidence-based adjuvant treatment strategies.
Individualized Learning in Robotic Ileal pouch-anal anastomosis
Violante, Tommaso , Sassun, Richard , Mishra, Nitin , Merchea, Amit , Violante, Tommaso , Sassun, Richard , Ferrari, Davide, Behm, Kevin T. , Vierkant, Robert A. , Larson, David W.

Annals of Surgery | August 12, 2025 | Volume: No volume available | Issue: No issue available | Pages: No page available

10.1097/sla.0000000000006907 Get It

Objective: This study establishes objective benchmarks for robotic ileal pouch-anal anastomosis (IPAA) proficiency, evaluating individual surgeon learning curves using risk-adjusted cumulative sum (RA-CUSUM) analysis. Summary Background Data: IPAA is a standard surgical treatment for conditions like refractory ulcerative colitis; robotic assistance offers potential advantages. However, the robotic IPAA learning curve is not clearly defined. Conventional analyses often overlook significant inter-surgeon variability and patient-specific factors, hindering surgical training optimization. Methods: A multi-site retrospective analysis of 123 consecutive robotic IPAA procedures performed by 11 surgeons between June 2015 and December 2023 was conducted. Patient-related variables were used for risk adjustment, and RA-CUSUM charts were generated to assess 30-day complications, operative time, and length of hospital stay at both aggregate and individual surgeon levels. Results: Aggregate RA-CUSUM data indicated general improvement trends for operative time and length of stay, alongside higher-than-expected complication rates in the early phase. Disaggregated analyses at the individual surgeon level revealed significant heterogeneity in performance trajectories and learning patterns across all three outcomes, directly challenging the concept of a standardized, uniform learning curve. Although postoperative complication and length of stay outcomes did not significantly differ between surgeons, operative time varied significantly. Conclusions: The acquisition of skill in robotic IPAA is a highly individualized process, suggesting the traditional uniform learning curve model is insufficient for contemporary surgical education. These findings strongly advocate for a shift towards personalized training paradigms that incorporate deliberate practice, targeted feedback, and simulation to optimize learning and patient outcomes.
Tumor Deposits in Colon Cancer
Sassun, Richard , McKenna, Nicholas P , Sassun, Richard , McKenna, Nicholas P.

Diseases of the Colon & Rectum | June 18, 2025 | Volume: 68 | Issue: 9 | Pages: 1038-1040

10.1097/dcr.0000000000003864 Get It

Impact of elective surgery on tumor necrosis factor‐α, interleukin‐6 and quality of life in uncomplicated diverticular disease
Sassun, Richard , Roufael, Francesca, Crippa, Jacopo , Achilli, Pietro , Dinuzzi, Vincenza Paola , Maggioni, Dario, Costanzi, Andrea , Siracusa, Claudia , Leoni, Valerio , Mari, Giulio , Achilli, P , Larson, David Wesley, Crippa, J , Sassun, Richard , Magistro, Carmelo , Bertoglio, Camillo Leonardo , Montroni, Isacco , Spinelli, Antonino , Dominici, Roberto , Larson, David W.

Colorectal Disease | June 10, 2025 | Volume: 27 | Issue: 6 | Pages: No page available

10.1111/codi.70132 Get It

Abstract Aim Growing evidence suggests that immune/inflammatory pathways play a crucial role in the persistence of symptoms in diverticular disease (DD). We hypothesize that chronic diverticulitis triggers a self‐sustained inflammatory status which can be detected by measuring the levels of tumor necrosis factor‐α (TNF‐α) and interleukin‐6 (IL‐6). The aim of this study was to investigate the systemic levels of TNF‐α and IL‐6 before and after elective surgery in patients with DD, and their relationship with the gastrointestinal quality of life index (GIQLI) score. Method This prospective multicentric study enrolled patients from the Diverticular Disease Registry (DDR‐Trial, NCT04907383). All adult patients diagnosed with symptomatic uncomplicated diverticular disease (SUDD), uncomplicated recurrent diverticulitis (URD) and smouldering diverticulitis (SmD) between 1st December 2022 and 31st December 2023 were included in this study. Exclusion criteria were as follows: no surgery, a concurrent chronic immunomodulated systemic disease, a SARS‐CoV‐2‐positive test in the previous 12 months, a history of cancer in the previous 5 years, patients treated with immunomodulators, an American Society of Anesthesiologists category of class IV, and complicated acute diverticulitis. Results Seventy‐two patients were included: 52 (72%) with URD, 11 (15%) with SUDD, and nine (13%) with SmD. The median postsurgery – presurgery (Δ)IL‐6 and ΔTNF‐α levels were −16.8 and −17.3 pg/mL, respectively ( p < 0.001 for both; Wilcoxon test). Spearman correlation revealed a significant, negative association between the ΔGIQLI and the ΔIL‐6, as well as the ΔTNF‐α ( p < 0.001 for both). Greater reduction in the levels of IL‐6 and TNF‐α following surgery are associated with higher GIQLI scores postoperatively. Conclusion Patients with chronic diverticulitis may experience persistent systemic inflammation driven by a colonic trigger. Surgical removal of this trigger appears to enhance GIQLI outcomes reducing IL‐6 and TNF‐α across surgery.
Pathological staging predicts survival more accurately than clinical staging in locally advanced rectal cancer following total neoadjuvant therapy
Ng, Jyi Cheng , Sassun, Richard , Sileo, Annaclara , Perry, William , Mathis, Kellie L. , Larson, David W. , Larson, David W , Cheng, Jyi Ng , Perry, William R , Sassun, Richard

British Journal of Surgery | March 11, 2025 | Volume: 112 | Issue: 3 | Pages: No page available

10.1093/bjs/znaf034 Get It

Validated Integration of Tumor Deposits in N Staging for Prognostication in Colon Cancer
Sassun, Richard , Sileo, Annaclara , Ng, Jyi Cheng , Violante, Tommaso , Gomaa, Ibrahim A. , Mandrekar, Jay , Rumer, Kristen K. , Gomaa, Ibrahim , Violante, Tommaso , Cheng, Jyi Ng , Sassun, Richard , McKenna, Nicholas P. , Larson, David W.

JAMA Surgery | February 5, 2025 | Volume: 160 | Issue: 4 | Pages: 408

10.1001/jamasurg.2024.6729 Get It

Importance Tumor deposits have prognostic value in colon cancer, but the current American Joint Committee on Cancer (AJCC) staging only considers them if there are no concurrent positive lymph nodes. Objective To devise a staging system for colon cancer by integrating counts of tumor deposits with positive lymph nodes while retaining the current AJCC staging framework. Design, Setting, and Participants This retrospective cohort study examines data from a large-volume, tertiary care center database (January 2010 through March 2023 with follow-up until December 2023) and the population-based National Cancer Database (January 2010 through December 2020 with follow-up until December 2021). Participants were adults (age 18-75 years) with stage III colon adenocarcinoma who underwent chemotherapy, and had a specified positive lymph node count and tumor deposit count were selected. Exposure A real positive lymph nodes count was developed and used to derive Sassun-Mayo N/tumor, lymph node, and metastasis (TNM) stages that were compared with the AJCC N/TNM stages. Main Outcomes and Measures Receiver operating characteristic (ROC) curves and Kaplan-Meier analyses for 3-year overall survival were performed to assess the efficiency of the 2 staging systems. The concordance index was used for validation using the National Cancer Database. Results From a total patient number of 11 162 (institutional) and 848 704 (national), the final patient numbers were 788 and 77 790, respectively. The institutional database patients had a mean (SD) age of 58.5 (11.5) years; there were 433 male patients (54.9%) and 355 female (45.1%). The national database patients had a mean (SD) age of 59.3 (10.6) years; there were 40 315 male patients (51.8%) and 37 475 female (48.2%). ROC curve areas were improved using the Sassun-Mayo stages (3-year death for AJCC TMN, 0.63 [95% CI, 0.57-0.69] vs 0.66 [95% CI, for 0.60-0.72] for Sassun-Mayo TNM). Kaplan-Meier curves revealed visible overlaps among AJCC N stages, which were absent in the Sassun-Mayo N stages. The concordance index in the Sassun-Mayo N/TNM stages was 0.611 and 0.616, respectively, while in the AJCC N/TNM stages, it was 0.598 and 0.606, respectively. Patients upstaged from N1 to N2 (n = 10 307; 13.2%) had a 3-year overall survival rate nearly identical to that of AJCC N2a patients. Additionally, 3001 patients (3.9%) were upstaged from N2a to N2b, indicating that 13 308 patients (17.1%) with stage III colon cancer across cohorts were understaged. Conclusions and Relevance This study found that Sassun-Mayo N/TNM staging provided superior overall survival stratification compared with the current AJCC staging, suggesting that their implementation could improve prognostication in colon cancer.
Neoadjuvant immunotherapy versus adjuvant chemotherapy in anorectal melanoma
Sassun, Richard , Sileo, Annaclara , Ng, Jyi Cheng , Violante, Tommaso , Gomaa, Ibrahim A. , Block, Matthew S. , Perry, William , Rumer, Kristen K. , Larson, David W. , Larson, David W , Violante, Tommaso , Cheng, Jyi Ng , Perry, William R , Sassun, Richard , Sileo, Annaclara , McKenna, Nicholas P.

British Journal of Surgery | November 4, 2024 | Volume: 111 | Issue: 11 | Pages: No page available

10.1093/bjs/znae269 Get It