1 Department of Surgery. Hospital General Universitario Dr. Balmis de Alicante, Alicante Spain; ISABIAL: Instituto de Investigación Sanitaria y Biomédica de Alicante, Alicante Spain; Department of Pathology and Surgery, Universidad Miguel Hernández, Alicante Spain.
2 Department of Surgery. Hospital Auxilio Mutuo, San Juan Puerto Rico.
3 Department of Surgery, Hospital Universitario de Badajoz, Badajoz Spain; University of Extremadura, Badajoz Spain.
4 Department of Surgery, Clinica Universidad de Navarra, Pamplona Spain.
5 Department of Surgery, Hospital Clínico Universitario, University of Valencia, Biomedical Research Institute, Valencia Spain.
6 Department of Surgery, Hospital Universitario de Bellvitge, Hospitalet de Llobregat, Barcelona Spain.
7 Department of Surgery, Hospital Universitario de Getafe, Getafe Spain.
8 Hospital Dr. Peset, Valencia Spain.
9 Department of Surgery, Hospital Universitario de Guadalajara, Guadalajara Spain.
10 Department of Surgery, Hospital Universitario Virgen de las Nieves, Instituto de Investigación Biosanitaria ibs.GRANADA, School of Medicine, University of Granada, Granada Spain.
11 Department of Surgery. Hospital General Universitario Dr. Balmis de Alicante, Alicante Spain; ISABIAL: Instituto de Investigación Sanitaria y Biomédica de Alicante, Alicante Spain.
12 Department of Surgery, Hospital General Universitario Dr. Balmis. Alicante Spain; ISABIAL: Instituto de Investigación Sanitaria y Biomédica de Alicante, Alicante Spain.
13 Department of Surgery, Hospital Auxilio Mutuo, San Juan Puerto Rico.
14 Department of Surgery, Complejo Hospitalario de Badajoz Spain.
15 Department of Surgery, Hospital Universitario Miguel Servet, Zaragoza Spain.
16 Department of Surgery, Clínica Universitaria de Navarra, Pamplona Spain.
17 Department of Surgery, Hospital Clínico de Valencia, University of Valencia, Biomedical Research Institute, Valencia Spain.
18 Hospital Universitario de Getafe, Getafe Spain.
19 Department of Surgery, University of Puerto Rico School of Medicine, Puerto Rico.
20 Hospital Universitario de Guadalajara, Guadalajara Spain.
21 Hospital Universitario Virgen de las Nieves, Granada Spain.
22 Universidad de Granada, Granada Spain; Department of Pathology and Surgery, Universidad Miguel Hernández, Alicante Spain.
23 Department of Surgery, Hospital General Universitario Dr. Balmis. Alicante Spain; ISABIAL: Instituto de Investigación Sanitaria y Biomédica de Alicante, Alicante Spain; Department of Pathology and Surgery, Universidad Miguel Hernández, Alicante Spain.
24 H. U. Bellvitge.
25 H. U. Donostia.
26 H.U. Marqués de Valdecilla.
27 Clínica Universitaria de Navarra.
28 H.U. Virgen del Rocío.
29 H. Clínico de Valencia.
30 H. Insular de Gran Canaria.
31 H.U. Rio Ortega.
32 H. U. German Trias i Pujol; H. Mutua de Terrasa.