Techniques for mesoappendix transection and appendix resection: insights from the ESTES SnapAppy study
Authors: Bass Gary Alan , Kaplan Lewis J. , Forssten Maximilian Peter , Walsh Thomas N. , Cao Yang , Mohseni Shahin ,   ESTES SnapAppy Group, Ahl Hulme Rebecka , Biloslavo Alan , Kurihara Hayato , Martinez-Casas Isidro , Pereira Jorge , Pourlotfi Arvid , Ryan Éanna J. , Tolonen Matti , Louri Nayef , Nedham Fatema , Hashem Jamal , Corbally Martin , Farhan Abeer , Al Hamad Hamad , Elhennawy Rawan , AlKooheji Mariam , AlYusuf Manar , Aknouche Wissal , Zeidan Anas A. , Alsaffar Yusuf S. , Lipping Edgar , Talving Peep , Saar Sten , Graumann Katrina , Kibuspuu Liis , Harkov Eduard , Aaltonen Gisele , Sillman Iines S. , Haapanen Sami , Lampela Hanna , Sammalkorpi Henna , Eskola Sofia , Laakso Altti , Back Johan , Kettunen Ulla , Nummi Antti M. , Szwedyc Anika , Nykänen Taina , Rantala Rolle , Mäkäräinen-Uhlbäck Elisa J. , Meriläinen Sanna A. , Huhta Heikki I. , Rintala Jukka M. J. , Laitakari Kirsi E. M. , Lietzen Elina , Salminen Paulina , Rapola Risto K. A. , Zangouri Vahid , Karami Mohammad Y. , Tahmasebi Sedigheh , Akrami Majid , Golchini Alireza , Bahrami Faranak , Johnston Sean M. , Lim Sean T. , Ahonkhai Irele Ifijeh , Eltagani Eltahir , Ryan Odhran K. , O’Driscoll-Collins Ailbhe , O’Neill Aine , Penny Zakiya , Kelly Orlaith , Cullinane Carolyn , Reynolds Ian , Heneghan Helen , Martin Sean , Winter Des , Davey Matthew , Alkhattab Maha , Lowery Aoife J. , Kerin Michael J. , Hogan Aisling M. , Davey Martin S. , Oh Ke En , Kabir Syed Mohammad Umar , Huan Huilun , Aziz Charlotte , Sugrue Michael , Ryan Jessica M. , Connelly Tara M. , Alhazmi Mohammad , Al-Mukhaizeem Youssef , Cooke Fiachra , Neary Peter M. , Hill Arnold D. K. , Boland Michael R. , Lloyd Angus J. , Fallon Frances , Cleere Eoin F. , Toale James , Boland Patrick A. , Devine Michael , Keady Conor , Hunter Sarah , Barry M. Kevin , Kelly Michael E. , O’Dowling Aidan T. , Creavin Ben , Kavanagh Dara O. , Neary Paul , Ridgway Paul F. , McCarrick Cathleen A. , Bolger Jarlath , Maguire Barry , Keogh Cian , Chawla Surbhi , Conneely John , McCormack Emilie , Shanahan Ben , Raftery Nicola , Rice Darragh , McInerney Niall , Stakelum Aine , Mares Jan , Tan Jonavan , Hanna Mark , Balasubramanian Ishwarya , Fleming Christina , Barsky Guy , Shaked Gad , Giudici Simone , Ceolin Martina , Mei Simona , Mazzarella Francesca , Zucca Annalisa , Terranova Susanna , de Manzini Nicolo , Visconti Diego , Doria Emanuele , Santarelli Mauro , Scotton Giovanni , Notte Francesca , Bertelli Giacomo , Malpaga Anna , Armatura Giulia , Frena Antonio , Tartaglia Dario , Coccolini Federico , Cremonini Camilla , Cicuttin Enrico , Mazzoni Alessio , Chiarugi Massimo , Azevedo Constança M. , Mendes Filipa D. , Faria Luis Q , Nazario Carlos , Machado Daniela , Semiao Miguel , Casimiro Carlos , Pinto Jose , Pavão Tiago , Pereira Raquel , Barbosa Bruno , Tenreiro Nadia , Ferreira Catia , Guidi Goncalo , Martins Daniela C. , Leal Clara , Vieira Bruno B. , Castro Luís S. , Faria Aldara , Figueira Alberto , Sousa Mauro , Rodrigues Pedro , Roquette Rodrigo , Ribeiro Ricardo , Cardoso Paulo , Domingues Joana , Manso Maria Isabel , Pereira Rute , Revez Tatiana , Dumbrava Bogdan D. , Turcu Florin , Hutopila Ionut , Banescu Bogdana , Filip Gerald , Copaescu Catalin , Valmorisco Marcos Alba , Martín Isabel Manzano , Garcíade de Arboleya Rocio Martín , Ortega Seda José , Rodríguez González Pablo , Becerra Toro Jose Antonio , Rodríguez Lara Enrique , González Minchón Jose Antonio , Segura-Sampedro Juan José , Jerí-McFarlane Sebastián , Gil-Catalán Alejandro , Craus-Miguel Andrea , Fernández-Vega Laura , González-Argenté Xavier , Estaire-Gómez Mercedes , Fernández-Pacheco Borja Camacho , Vitón-Herrero Rebeca , Jimenez-Higuera Elisa , Barbero Alejandro , Valverde José M. , Colás-Ruiz Enrique , Escales-Oliver Maria del Mar , Claramonte-Bellmunt Olga , Castro-Suárez Marta , Pagés-Valle Naila , Cifuentes-Ródenas José Andrés , Alvarez Marta Merayo , Campos Jose Luis Michi , González Luis Alejandro García , Aguilera Beatriz Carrasco , Menéndez Jaime Iturbe , Miravalles Jose Luis Rodicio , Haro Carmen Rodríguez , O’Sullivan Sara Núñez , Virosta Mariana García , O’Reilly María Hernández , Balciscueta-Coltell Izaskun , Lorenzo-Perez Javier , Martinez-Alcaide Sonia , Martinez-Ramos Susana , Sebastian-Fuertes Maria , Gomez-Romer Laura , Pelloni Maria M. , Rahy-Martín Aida Cristina , Yepes-Cano Andrés Felipe , Reguera-Rosal Julio , Lopez-Ruiz Jose A. , Marenco Beatriz , Retamar-Gentil Marina , Romero-Vargas Estela , Gil-Olarte Angeles , Landaluce-Olavarria Aitor , Estraviz-Mateos Begoña , De Francisco-Rios Jose-Mario , Sainz-Lete Aitor , Emaldi-Abasolo Ane , Leon-Valarezo Manolo , Lopes Claudia C. Moreira , Lizarazu Perez Aintzane , Rodriguez Gonzalez Araceli , Augusto Ponce Iñigo , Goena Iglesias Ignacio Maria , González-Prado Cristina , Cabriada Guillermo , López Beatriz , Otero Michelle C. , Muñoz-Plaza Nerea , Palomo Alberto , Mendoza-Moreno Fernando , Díez-Alonso Manuel , García-Moreno-Nisa Francisca , Matías-García Belén , Ovejero-Merino Enrique , Quiroga-Valcárcel Ana , Sánchez-Guillén Luis , Oller-Navarro Inmaculada , Soler-Silva Álvaro , Sanchís-López Antonio Francisco , Blanco-Antona Francisco , Muñoz-Bellvis Luis , López-Sánchez Jaime , Garrosa-Muñoz Sonsoles , Barón-Salvador Beatriz , Nieto-Arranz Juan Manuel , Campos-Serra Andrea , Gràcia-Roman Raquel , Muñoz-Campaña Anna , Zerpa-Martin Carla , Torrecilla-Portoles Andrea , Landa Tessa , Durán Muñoz-Cruzado Virginia , Pareja-Ciuró Felipe , Aparicio-Sánchez Daniel , Perea del Pozo Eduardo , García-Moriana Antonio Jesús , Dios-Barbeito Sandra , García-Sánchez Carlos , Turrado-Rodriguez Victor , Termes-Serra Roser , Gonzalez-Atienza Paula , Morales-Sevillano Xavier , Torroella Alba , Ginestà César , Escartín Alfredo , Gomez Ferney , Pinillos Ana , Ortega Jaume , Lopez Guillermo , Gutierrez Eric , Membrilla-Fernandez Estela , Ocho-Segarra Francisco , González-Castillo Ana María , Pelegrina-Manzano Amalia , Guzmán-Ahumada Juan , Sancho-Insenser Juan Jose , García-Jiménez María Lourdes , Castro-Diez Laura , González-Bermúdez Manuel , Torres-Díaz Mónica , Madarro Pena Carla , Blanco Rodríguez Angélica , Trivedi Dhanisha , Reda Souheil , Edvardsson Hans , Strömmer Lovisa , Caragounis Eva-Corina , Sillén Karin , Warfvinge Sofia , Bergstedt Fredrik , Enström Philip , Olsson Harald , Rosemar Anders , Young Nathalie , Popowicz Agnieszka , Lerström Johanna , Jäderbo Johanna , Hammarqvist Folke , Zacharias Hanna , Wikström Maria B. , Stene Hurtsén Anna , Bayadsi Haytham , Jansson Emma , Brunstrom Nils , Malers Ellen B. , Loftås Per I. , Möller Anders , Atanasova Elena , Zwicky Simone N. , Schnüriger Beat , Rutka Olga , Kattakayam Arjun T. , Alam Mushfique , Taylor John V. , Mihailescu Andrei , Karip Eszter T. , Zeb Ehtisham , O’Connor Adam , Pokusevski Goran , Khan Mansoor , Florance Charlotte , Swaminathan Christie , Jaunoo Shameen , Sajid Mohammed , Duffy Caoimhe C. , Rees John , Seamon Mark J. , Martin Niels D. , McCurry Ian J. , Vail Emily A. , Bormann Bradford C. , Cullinane Daniel C. , Sawhney Jaswin S. , Dreifus Jonathan , Sheppard Forest R. , Coimbra Raul , Albini Paul , Edwards Sara 
Published: January 2023

Abstract
Introduction
Surgically managed appendicitis exhibits great heterogeneity in techniques for mesoappendix transection and appendix amputation from its base. It is unclear whether a particular surgical technique provides outcome benefit or reduces complications.

Material and methods
We undertook a pre-specified subgroup analysis of all patients who underwent laparoscopic appendectomy at index admission during SnapAppy (ClinicalTrials.gov Registration: NCT04365491). We collected routine, anonymized observational data regarding surgical technique, patient demographics and indices of disease severity, without change to clinical care pathway or usual surgeon preference. Outcome measures of interest were the incidence of complications, unplanned reoperation, readmission, admission to the ICU, death, hospital length of stay, and procedure duration. We used Poisson regression models with robust standard errors to calculate incident rate ratios (IRRs) and 95% confidence intervals (CIs).

Results
Three-thousand seven hundred sixty-eight consecutive adult patients, included from 71 centers in 14 countries, were followed up from date of admission for 90 days. The mesoappendix was divided hemostatically using electrocautery in 1564(69.4%) and an energy device in 688(30.5%). The appendix was amputated by division of its base between looped ligatures in 1379(37.0%), with a stapler in 1421(38.1%) and between clips in 929(24.9%). The technique for securely dividing the appendix at its base in acutely inflamed (AAST Grade 1) appendicitis was equally divided between division between looped ligatures, clips and stapled transection. However, the technique used differed in complicated appendicitis (AAST Grade 2 +) compared with uncomplicated (Grade 1), with a shift toward transection of the appendix base by stapler (58% vs. 38%; p < 0.001). While no statistical difference in outcomes could be detected between different techniques for division of appendix base, decreased risk of any [adjusted IRR (95% CI): 0.58 (0.41–0.82), p = 0.002] and severe [adjusted IRR (95% CI): 0.33 (0.11–0.96), p = 0.045] complications could be detected when using energy devices.

Conclusions
Safe mesoappendix transection and appendix resection are accomplished using heterogeneous techniques. Technique selection for both mesoappendix transection and appendix resection correlates with AAST grade. Higher grade led to more ultrasonic tissue transection and stapled appendix resection. Higher AAST appendicitis grade also correlated with infection-related complication occurrence. Despite the overall well-tolerated heterogeneity of approaches to acute appendicitis, increasing disease acuity or complexity appears to encourage homogeneity of intraoperative surgical technique toward advanced adjuncts.