Efficacy of amoxicillin/clavulanic acid after surgical drainage of perianal abscess in the prevention of the development of anal fistula (PERIQxA study): study protocol for a multicenter randomized, double-blind clinical trial
Authors: Polaino Moreno Verónica , Caballero-Bermejo Antonio F. , Artés Caselles Mariano , Serrano González Javier , Remírez Arriaga Xabier , González Alcolea Natalia , Equisoain Azcona Aritz , Iglesias García Eva , Lucena de la Poza José Luis , Sánchez Movilla Arsenio , Ruiz-Antorán Belén ,   PERIQxA Study Group, Alonso Sebastián Isabel , Melero Montes Daniel , León Fernández Carmen , Álvarez Sánchez Jesús , Muñoz Rodríguez Joaquín , González González Juan , García-Oria Serrano Miguel , Sánchez Ramos Ana , García Pavía Arturo , Jiménez Cubedo Elena , Román García de León Laura , Chaparro Cabezas Maria Dolores , López Monclús Javier , Pueyo Rabanal Alberto , Cea Soriano Matías , Artuñedo Pe Pedro , Rial Justo Xiana , Suárez Sánchez Miguel , Gil Cidoncha Lucía , Martín Rodrigo María del Pilar , Torguet Muñoz María , Fernández Rodriguez Manuel , Grillo Marín Cristián , Fidalgo Martínez Celia , Callau Pontaque Javier , Galindo Jara Pablo , Colao García Laura , Díaz Pérez David , Gallardo Herrera Ana Belén , Esteban Agustí Enrique , Hernández Bartolomé Miguel A. , Gutierrez Samaniego María , García Llorente César , Rabadán Ruiz Lorenzo , Barriga Sánchez Raquel , Núñez Tasaico Hector Ernesto , Zabala Salinas Jaime , Almeida Romera Natalia , Ríos Blanco Raquel , Josa Martínez Benito Miguel , Bra Insa Eneida , Sagarra Cebolla Elena , García Aparicio Mónica , Garaulet González Paloma , San Pío Carvajal Eduardo , Fraile Vasallo Miriam , Muros Bayo José Manuel , Olivares Pizarro Sergio Pedro , Herrera Cabrera Vicente , Corrales Castillo Isaac Silvio , Pertejo Muñoz Elsa , Ortega García Ricardo , Sánchez Gollarte Ana , Maqueda González Rocío , Sáez Rodríguez Carlos , Álvarez Gallego Mario , Díaz San Andrés Beatriz , Cantero Cid Ramón , González Gómez Carolina , Rubio Pérez Inés , Tone Villanueva Fernando , Asensio Gómez Luis , Díaz Serrano Esteban , Monje Vera Blanca , Castillo Marcos Celia , Suárez Enriquez Ana Belén , Abad Moret Rebeca , Huerta Serracin Kriss 
Published: February 2024

Abstract
Background
Anorectal fistula, which is a relatively common pathology, is the chronic manifestation of the acute perirectal process that forms an anal abscess. The development of a fistula after incision and drainage of an anal abscess is seen in approximately 26–37%. Its treatment is a relevant topic, and the role of the use of antibiotic therapy in its prevention remains controversial, after the publication of several studies with contradictory results and several methodological limitations. Our hypothesis is that the combination of amoxicillin and clavulanic acid will reduce the incidence of anal fistula.

Method
The aim of this study is to evaluate the efficacy of antibiotherapy after surgical drainage of perianal abscess in the development of perianal fistula. The PERIQxA study is a multicenter, randomized, double-blind controlled trial. The study has been designed to include 286 adult patients who will be randomly (1:1) assigned to either the experimental (amoxicillin/clavulanic acid 875/125 mg TDS for 7 days) or the control arm (placebo). The primary outcome measure is the percentage of patients that develop perianal fistula after surgery and during follow-up (6 months).

Discussion
This clinical trial is designed to evaluate the efficacy and safety of amoxicillin/clavulanic in the prevention of perianal fistula. The results of this study are expected to contribute to stablish the potential role of antibiotherapy in the therapeutics for anal abscess.

Trial registration
EudraCT Number: 2021–003376-14. Registered on November 26, 2021.