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Fong, Zhi Ven

https://orcid.org/0000-0001-6398-413X

Mayo Clinic

Mayo Clinic

Citations 37

The Association of Extended Venous Thromboembolism Prophylaxis and Venous Thromboembolism After Cancer Surgery
Tan, Po Hong, Lillemoe, Keith D., Stucky, Chee-Chee, Brady, Justin T., Pockaj, Barbara A. , Cronin, Patricia, Potter, Alexandra L. , Yang, Chi-Fu Jeffrey, Mavros, Michail N., Fagenholz, Peter J. , Kastrinakis, William V., Poruk, Katherine E. , Wasif, Nabil , Qadan, M., Pockaj, Barbara, Poruk, Katherine, Fong, Zhi Ven , Lillemoe, Keith D. , Stucky, Chee-Chee, Brady, Justin T. , Cronin, Patricia, Linderman, George C. , Yang, Chi‐Fu Jeffrey , Mavros, Michail N. , Thiels, Cornelius A. , Habermann, Elizabeth B. , Chang, Yu‐Hui , Qadan, Motaz

Journal of the National Comprehensive Cancer Network | March 19, 2026 | Volume: 24 | Issue: 4 | Pages: No page available

10.6004/jnccn.2025.7128 Get It

Background: ASCO recommends extended venous thromboembolism (VTE) prophylaxis with low-molecular-weight heparin (LMWH) or direct oral anticoagulants (DOACs) following cancer surgery. However, these recommendations were based on trials using routine venography, which detects asymptomatic VTEs, and real-life efficacy is not well studied. We aimed to assess the association of extended VTE prophylaxis with the incidence of clinically significant VTE after elective cancer surgery. Patients and Methods: In this retrospective, population-based cohort study, we identified patients who underwent surgical resection for lung, breast, esophageal, gastric, pancreas, and colon cancer from 2010 to 2017 using the SEER–Medicare linked dataset. Patients were divided into 1 of 2 main groups for comparative analyses: those who received extended VTE prophylaxis after cancer surgery and those who did not. Patients who received extended VTE prophylaxis after cancer surgery were identified as those prescribed prophylactic doses of LMWH or a DOAC within 7 days of discharge, as captured in Medicare Part D files. Results: A total of 113,739 Medicare beneficiaries were identified, of whom 1,570 (1.4%) received extended VTE prophylaxis. There was a year-over-year increase in the use of extended VTE prophylaxis during the study period, rising from 0.6% in 2010 to 3.3% in 2017. The overall incidence of VTE was 1.6% at 1 month, 4.3% at 6 months, 5.7% at 12 months, with significant differences observed across cancer types ( P <.001). However, patients who received extended VTE prophylaxis had a higher 1-year cumulative incidence of postoperative VTE compared with those who did not (11.4% vs 5.3%; P <.001), an association that was consistent across cancer sites. In adjusted analyses, extended VTE prophylaxis was independently associated with an increased risk of VTE (hazard ratio, 1.6; 95% CI, 1.3–2.0; P <.001). Extended prophylaxis was also associated with a higher 1-year incidence of bleeding events compared with patients who did not receive prophylaxis (12.0% vs 8.5%; P <.001). Conclusions: The utilization of extended VTE prophylaxis after cancer surgery remains low, although it has increased every year. Paradoxically, patients who received extended VTE prophylaxis had higher incidences of clinically significant VTE and bleeding compared with those who did not, likely reflecting patient selection and surveillance bias after surgery. In light of these findings, national guidelines recommending postoperative extended VTE prophylaxis, and its use as a surrogate for quality of care, should continue to be re-examined.
Conflation of Covariate Adjustments With Causal Effects—The Table 2 Fallacy in Surgical Literature
Mah, Alexis , Miller, Richard M., Hallet, Julie H., Ven Fong, Zhi, Hallet, Julie , Fong, Zhi Ven

Annals of Surgery | February 18, 2026 | Volume: 284 | Issue: 2 | Pages: 445-447

10.1097/sla.0000000000007034 Get It

Redefining Upfront Resectable Pancreatic Ductal Adenocarcinoma: Should Vein Abutment Matter?
Tan, Po Hong, Thiels, Cornelius A., Poruk, Katherine E. , Miller, R., Hor, Hoe Yan , Tu, Melody Pi Yin , Huyser, Michelle R., Stucky, Chee-Chee, Wasif, Nabil , Bold, Richard J. , Smoot, R., Starlinger, Patrick P., Warner, Susanne G., Kendrick, M., Stauffer, John A., Truty, M., Fong, Zhi Ven, _, _, Poruk, Katherine, Miller, Richard Max, Thiels, Cornelius A. , Stucky, Chee‐Chee , Starlinger, Patrick , Warner, Susanne G. , Kendrick, Michael L. , Stauffer, John , Truty, Mark J. , Fong, Zhi Ven

Journal of the National Comprehensive Cancer Network | February 9, 2026 | Volume: 24 | Issue: 2 | Pages: 27-33

10.6004/jnccn.2025.7097 Get It

Background: Upfront resectable pancreatic ductal adenocarcinoma (PDAC) is defined by the NCCN as disease with ≤180° portomesenteric vein (PMV) abutment. However, the clinical significance of PMV abutment in this cohort remains unexplored, and we sought to investigate its impact. Methods: This multi-institutional study included patients who underwent pancreatoduodenectomy (PD) for upfront resectable PDAC from 2002 to 2023. Patients with PDAC with ≤180° PMV abutment were compared with those without. Overall survival (OS) was compared and stratified based on whether patients underwent upfront surgery or neoadjuvant therapy (NAT). Results: Among 1,446 patients included, 521 (36.0%) had PMV abutment. Median OS for patients with PMV abutment was 28.8 months compared with 31.2 months for those without ( P =.17). In a stratified analysis of patients who underwent upfront surgery, patients with PMV abutment had worse OS (19.2 vs 27.6 months; P <.05) and lower R0 resection rates (63.1% vs 87.2%; P <.05) compared with those without. However, in patients who underwent NAT, this difference in R0 resection rate was not observed (91.4% vs 94.0%, respectively; P =.27). Furthermore, there was no significant difference in median OS with NAT (42.5 vs 51.6 months, respectively; P =.48). Conclusions: In this largest cohort to date of patients with upfront resectable PDAC, PMV abutment was associated with worse OS compared with no PMV abutment when an upfront resection strategy was used. The use of NAT in patients with PMV abutment mitigated this survival difference with increased R0 resection rates. These findings suggest that patients with upfront resectable PDAC with PMV abutment benefit from a NAT approach for optimal survival outcomes, and that the current criteria guidelines need to be redefined.
Association Between Surgical Robotic Availability and Open Operation Rate: A Geographic Analysis
Anderson, Charles K, Wall-Wieler, Elizabeth, Fazal, Zahra , Sahai, Nikhil, Hoeler, Don, Lee, Pamela C, Ven Fong, Zhi, Fong, Zhi Ven , Wall‐Wieler, Elizabeth , Mitzman, Brian

Journal of the American College of Surgeons | February 9, 2026 | Volume: 243 | Issue: 1 | Pages: 193-200

10.1097/xcs.0000000000001837 Get It

BACKGROUND: Despite the widespread adoption of minimally invasive surgery in the US, disparities in its use persist. One unexplored contributor is geographic access to robotic surgical systems. This study evaluates the geospatial association between: (1) Social Vulnerability Index (SVI) and open surgery rates, (2) availability of robotic systems and open surgery, and (3) open surgery rates in demographically similar areas with differing robotic access. STUDY DESIGN: Data from 6 sources were linked at the ZIP Code Tabulation Area (ZCTA) level to identify hospitals and to extract procedure modality, presence of robotic systems, and area characteristics. Regression analysis assessed the association between SVI and open surgery rates. Open rates were then compared between hospitals with and without robotic systems. Propensity score matching was used to compare open rates across matched ZCTAs by robotic access and SVI levels. RESULTS: Higher social vulnerability was associated with increased open surgery rates (estimate = 0.20; p < 0.01), with rates ranging from 18.3% in low-vulnerability areas to 32.7% in high-vulnerability areas. Among 3,446 eligible ZCTAs, 57% had at least 1 robotic system. ZCTAs without robotic systems had higher open surgery rates (42.9 vs 19.4 per 100 procedures; relative rate = 2.21; p < 0.01). This association remained significant after matching (relative rate = 1.66; p < 0.01), for the low-mid- and high-SVI strata, and 3 of the 5 procedures examined. CONCLUSIONS: When correcting for geographic variation, the availability of robotic surgery was associated with a decrease in open surgery rates.
Blood loss during pancreatic surgery: defining minimal clinically significant difference using standardized estimation
Perri, Giampaolo , Ribeiro, Tiago , Maekawa, Aya , Dall’Olio, Tommaso, Romandini, Elisa, Ghorbani, Poya , Marchegiani, Giovanni , Sparrelid, Ernesto , Hallet, Julie , Cillo, Umberto , Marchegiani, Giovanni , Hallet, Julie , Perri, Giampaolo , Fong, Zhi Ven

British Journal of Surgery | October 15, 2025 | Volume: 112 | Issue: 10 | Pages: No page available

10.1093/bjs/znaf215 Get It

Metabolic inflammation and cancer risk: A potential target with GLP‐1 agonist or bariatric surgery?
Cheung, Dillon, Yu, Stephanie, Lim, Pei‐Wen , Fong, Zhi Ven , Fong, Zhi Ven

Cancer | October 15, 2025 | Volume: 131 | Issue: 20 | Pages: No page available

10.1002/cncr.70124 Get It

The authors explore the association of remnant cholesterol and CRP with the longitudinal development of cancer in a prospective cohort study and if there is an opportunity to modulate risk with bariatric surgery or GLP‐1 agonist.
Revisiting Minimum Case Volume Recommendations for Complex Surgery in Contemporary Practice
Kartik, Akash , Stucky, Chee-Chee, Etzioni, David A. , Bold, Richard J. , Wasif, Nabil , Ven Fong, Zhi, Cronin, Patricia A. , Etzioni, David, Bold, Richard, Fong, Zhi Ven , Chang, Yu‐Hui

JAMA | October 8, 2025 | Volume: 334 | Issue: 21 | Pages: 1945

10.1001/jama.2025.17274 Get It

This study examines the relevance of minimum case volume recommendations in contemporary practice.
Long-Term Survival After Surgical Resection for Rectal Cancer Is Associated With Textbook Outcome but Not Surgical Case Volume
Aly, Mohamed R., Stucky, Chee-Chee, Etzioni, David A. , Wasif, Nabil , Etzioni, David, Chang, Yu‐Hui , Fong, Zhi Ven

Annals of Surgery Open | August 18, 2025 | Volume: 6 | Issue: 3 | Pages: e601

10.1097/as9.0000000000000601 Get It

Objective: Analyzing textbook outcome (TO) following rectal cancer resection and its association with long-term survival when compared to hospital case volume alone. Background: TO is a quality metric representing the ideal result following complex cancer surgery. Prior studies have suggested improved long-term survival for rectal cancer patients undergoing surgery at HV institutions. Methods: Patients undergoing surgery for rectal adenocarcinoma from 2014 to 2015 were identified using the National Cancer Database. Low (LV), medium (MV), and high-volume (HV) hospital strata were defined by quartile cutoffs (low <25th, high >75th, and 25–75th medium volume). TO was achieved with adequate lymph node count (≥12), negative margins (R0 resection), length of stay <75th percentile, absence of 30-day readmission/mortality event, and appropriate plus timely systemic therapy. Adjusted analyses for long-term survival were performed using a hierarchical multivariable Cox regression model. Results: TO was achieved in 28.5% of 48,484 patients. LV or MV hospital patients were more likely to be older, uninsured/Medicaid, and less likely to achieve a TO (HV 31.2% vs MV 29.6% vs LV 23.2%, P < 0.001). TO was associated with improved 5-year survival (84.0% vs 72.0%, P < 0.001). On multivariable analyses, TO was the strongest protective factor against mortality (HR 0.60, 95% confidence interval = 0.56–0.64), even after controlling for case volume. Conclusions: Only 28.5% of patients undergoing resection for rectal cancer achieve TO. However, they had a 40% reduction in long-term mortality independent of hospital volume. Optimizing long-term survival in patients with rectal cancer can be achieved by TO criteria rather than increasing surgical case volume.
Variations in the Use of Outpatient Surgery
Sangaralingham, Lindsey R. , Houten, Holly K. Van , Kendrick, Michael L. , Etzioni, David A. , Hanson, Kristine, Sangaralingham, Lindsey, Fong, Zhi, Kendrick, Michael, Etzioni, David, Zhang, Chi , Hanson, Kristine T. , Fong, Zhi Ven , Chang, Yu‐Hui , Habermann, Elizabeth B. , Thiels, Cornelius A.

JAMA Network Open | July 31, 2025 | Volume: 8 | Issue: 7 | Pages: e2524165

10.1001/jamanetworkopen.2025.24165 Get It

ImportanceIdentification of factors associated with variation in outpatient surgery may further quality improvement efforts to safely reduce postoperative hospital length of stay nationally.ObjectivesTo explore variation in the use of outpatient surgery, incorporating patient, geographic, and hospital factors.Design, Setting, and ParticipantsThis retrospective cross-sectional study used deidentified administrative claims data from OptumLabs Data Warehouse. Participants included adults who underwent 1 of 10 general, urological, or gynecological operations between January 1, 2015, and June 30, 2021, in the US. Patients who underwent combined procedures or reoperations or had at least 15 Elixhauser comorbidities were excluded. Data were analyzed from July 26 to December 16, 2023.ExposureInpatient or outpatient surgical procedures.Main Outcomes and MeasuresMultilevel logistic regression assessed variation in the use of outpatient surgery rates by hospital characteristics (bed size, presence of trainees, and rural referral center status) and hospital census division, adjusting for patient factors (age, sex, number of Elixhauser comorbidities, year, and rural-urban commuting area). This multilevel model allowed for the sources of variability to be quantitatively attributed to patient characteristics, geography, and hospital characteristics.ResultsA total of 330 424 (72.3%) of 456 954 included patients underwent outpatient surgery. The median age was 54 (IQR, 41-67) years, and of those with data available, most patients were female (268 692 of 414 193 [64.9%]). The likelihood of outpatient surgery varied significantly by hospital census division for all 10 operations (eg, MIS salpingo-oophorectomy range, 29.6%-58.8%; P &amp;lt; .001). Variation in hospital census division contributed most to outpatient surgery for 8 of 10 operations compared with other patient and hospital characteristics. Hospital census division contributed the greatest degree to the variation in outpatient simple mastectomy (20.6%) and the least to outpatient open ventral hernia repair (0.7%). Multivariable analysis showed that the odds of outpatient surgery for patients from metropolitan areas were higher for minimally invasive salpingo-oophorectomy (odds ratio [OR], 1.62; 95% CI, 1.34-1.95) and open ventral hernia repair (OR, 1.16; 95% CI, 1.09-1.24). Hospitals with 400 or more beds were independently associated with decreased odds of outpatient surgery compared with hospitals with 50 to 199 beds for 4 of 7 operations (MIS paraesophageal hernia repair [OR, 0.58; 95% CI, 0.47-0.71; P &amp;lt; .001]; MIS cholecystectomy [OR, 0.73; 95% CI, 0.68-0.78; P &amp;lt; .001]; open ventral hernia [OR, 0.51; 95% CI, 0.46-0.57; P &amp;lt; .001]; MIS ventral hernia repair [OR, 0.66; 95% CI, 0.56-0.77; P &amp;lt; .001]). The presence of a residency training program was independently associated with increased odds of outpatient surgery for simple mastectomy (OR, 1.35; 95% CI, 1.16-1.58; P &amp;lt; .001) and mastectomy with reconstruction (OR, 1.50; 95% CI, 1.27-1.77; P &amp;lt; .001) and decreased odds of outpatient surgery for minimally invasive cholecystectomy (OR, 0.96; 95% CI, 0.92-1.00; P = .04), open ventral hernia repair (OR, 0.93; 95% CI, 0.86-1.00; P = .04), and total thyroidectomy (OR, 0.84; 95% CI, 0.71-1.00; P = .04).Conclusions and RelevanceIn this cross-sectional study, significant variation existed in the use of outpatient surgery in the US and appeared to be driven primarily by hospital geography. Addressing these variations may improve the use of resources.