{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,24]],"date-time":"2026-08-24T10:34:35Z","timestamp":1787567675527,"version":"build-2736575974"},"reference-count":30,"publisher":"MDPI AG","issue":"17","license":[{"start":{"date-parts":[[2026,8,24]],"date-time":"2026-08-24T00:00:00Z","timestamp":1787529600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Cancers"],"abstract":"<jats:p>Background: Robotic liver resections (RLRs) are rapidly expanding, yet the association between the learning curve, procedural complexity, and outcomes at intermediate-volume centers remains poorly defined. We evaluated the learning-curve trajectory and perioperative outcomes of a single surgeon\u2019s initial RLR experience according to procedural complexity (IWATE difficulty score). Methods: We retrospectively analyzed 58 consecutive RLRs at an intermediate-volume center. We stratified outcomes by IWATE difficulty category and chronological tertile (early\/middle\/late). Textbook outcomes (TOs) and a composite failure endpoint (conversion, major complications [Clavien\u2013Dindo \u2265 IIIa] and 90-day mortality) were also assessed. Learning-curve behavior was examined with CUSUM and risk-adjusted CUSUM (RA-CUSUM) analyses. Results: Fifty-four procedures (93.1%) were minor resections and four were major hepatectomies; two were classified as IWATE Expert difficulty. Median estimated blood loss was 100 mL; conversion occurred in 10.3%, overall morbidity in 10.3% and severe complications (Clavien\u2013Dindo \u2265 IIIa) in 3.4%, with no mortalities within 90 days. TOs were achieved in 69.0% using the Delphi (TOLS) definition and in 46.6% using a length-of-stay-extended definition. Operative time and length of stay increased significantly with IWATE difficulty (p &lt; 0.001 and p = 0.030), as did the composite failure endpoint (p = 0.039), whereas blood loss and complications did not. TOs decreased with difficulty under the extended definition (p = 0.016). No outcome except estimated blood loss differed across chronological tertiles (p = 0.032). Operative time was associated with the IWATE score (26.3 min per point; R2 = 0.32) but not with case order (p = 0.93). CUSUM and RA-CUSUM curves showed a non-linear, multiphase pattern without an identifiable inflection point, with extremes attributable to individual high-complexity procedures. Conclusions: In this exploratory single-surgeon series, consisting predominantly of minor resections, no case-number threshold could be identified, and perioperative outcomes were more closely associated with procedural complexity than with chronological experience, supporting a complexity-adjusted interpretation of RLR outcomes rather than a fixed case-number learning threshold.<\/jats:p>","DOI":"10.3390\/cancers18172739","type":"journal-article","created":{"date-parts":[[2026,8,24]],"date-time":"2026-08-24T09:20:02Z","timestamp":1787563202000},"page":"2739","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Perioperative Outcomes and Learning Curve for Robotic Liver Resection: An Exploratory Single-Surgeon CUSUM Analysis Stratified by IWATE Difficulty Score"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0256-1728","authenticated-orcid":false,"given":"Roberta","family":"Vella","sequence":"first","affiliation":[{"name":"IRCCS ISMETT\u2014UPMC Italy, Via E. Tricomi 5, 90127 Palermo, Italy"},{"name":"UPMC Italy, 90127 Palermo, Italy"},{"name":"Department of Precision Medicine in Medical, Surgical and Critical Area (MePreCC), University of Palermo, 90127 Palermo, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kejd","family":"Bici","sequence":"additional","affiliation":[{"name":"IRCCS ISMETT\u2014UPMC Italy, Via E. Tricomi 5, 90127 Palermo, Italy"},{"name":"UPMC Italy, 90127 Palermo, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sergio","family":"Li Petri","sequence":"additional","affiliation":[{"name":"IRCCS ISMETT\u2014UPMC Italy, Via E. Tricomi 5, 90127 Palermo, Italy"},{"name":"UPMC Italy, 90127 Palermo, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3987-9262","authenticated-orcid":false,"given":"Duilio","family":"Pagano","sequence":"additional","affiliation":[{"name":"IRCCS ISMETT\u2014UPMC Italy, Via E. Tricomi 5, 90127 Palermo, Italy"},{"name":"UPMC Italy, 90127 Palermo, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Pasquale","family":"Bonsignore","sequence":"additional","affiliation":[{"name":"IRCCS ISMETT\u2014UPMC Italy, Via E. Tricomi 5, 90127 Palermo, Italy"},{"name":"UPMC Italy, 90127 Palermo, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alessandro","family":"Tropea","sequence":"additional","affiliation":[{"name":"IRCCS ISMETT\u2014UPMC Italy, Via E. Tricomi 5, 90127 Palermo, Italy"},{"name":"UPMC Italy, 90127 Palermo, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sergio","family":"Calamia","sequence":"additional","affiliation":[{"name":"IRCCS ISMETT\u2014UPMC Italy, Via E. Tricomi 5, 90127 Palermo, Italy"},{"name":"UPMC Italy, 90127 Palermo, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Caterina","family":"Accardo","sequence":"additional","affiliation":[{"name":"IRCCS ISMETT\u2014UPMC Italy, Via E. Tricomi 5, 90127 Palermo, Italy"},{"name":"UPMC Italy, 90127 Palermo, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4946-512X","authenticated-orcid":false,"given":"Ivan","family":"Vella","sequence":"additional","affiliation":[{"name":"IRCCS ISMETT\u2014UPMC Italy, Via E. Tricomi 5, 90127 Palermo, Italy"},{"name":"UPMC Italy, 90127 Palermo, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Irene","family":"Vitale","sequence":"additional","affiliation":[{"name":"IRCCS ISMETT\u2014UPMC Italy, Via E. Tricomi 5, 90127 Palermo, Italy"},{"name":"UPMC Italy, 90127 Palermo, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Federica","family":"Chimenti","sequence":"additional","affiliation":[{"name":"IRCCS ISMETT\u2014UPMC Italy, Via E. Tricomi 5, 90127 Palermo, Italy"},{"name":"Department of General Surgery, Milano Bicocca University Hospital, 20126 Monza, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1411-3140","authenticated-orcid":false,"given":"Marco","family":"Barbara","sequence":"additional","affiliation":[{"name":"IRCCS ISMETT\u2014UPMC Italy, Via E. Tricomi 5, 90127 Palermo, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fabrizio","family":"di Francesco","sequence":"additional","affiliation":[{"name":"IRCCS ISMETT\u2014UPMC Italy, Via E. Tricomi 5, 90127 Palermo, Italy"},{"name":"UPMC Italy, 90127 Palermo, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9684-8035","authenticated-orcid":false,"given":"Salvatore","family":"Gruttadauria","sequence":"additional","affiliation":[{"name":"IRCCS ISMETT\u2014UPMC Italy, Via E. Tricomi 5, 90127 Palermo, Italy"},{"name":"UPMC Italy, 90127 Palermo, Italy"},{"name":"Department of General Surgery and Medical-Surgical Specialties, University of Catania, 95123 Catania, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,24]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"5549","DOI":"10.1097\/JS9.0000000000002567","article-title":"Robotic versus laparoscopic liver resection: A systematic review and meta-analysis of comparative studies","volume":"111","author":"Hoogteijling","year":"2025","journal-title":"Int. J. 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A"}],"container-title":["Cancers"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-6694\/18\/17\/2739\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,24]],"date-time":"2026-08-24T09:32:55Z","timestamp":1787563975000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-6694\/18\/17\/2739"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,8,24]]},"references-count":30,"journal-issue":{"issue":"17","published-online":{"date-parts":[[2026,9]]}},"alternative-id":["cancers18172739"],"URL":"https:\/\/doi.org\/10.3390\/cancers18172739","relation":{},"ISSN":["2072-6694"],"issn-type":[{"value":"2072-6694","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,8,24]]}}}