Myenteric plexitis: A frequent feature in patients undergoing surgery for colonic diverticular disease
Authors: Angelo Sidoni
Gian A Binda
Vincenzo Villanacci
Gabrio Bassotti
Rachele Del Sordo
Moris Cadei
Marianna Salemme
Riccardo Nascimbeni
Christoph A Maurer
Alessandra Manca
Nunzia Bernardini
Roberto Bandelloni
Maria P Dore
Gieri Cathomas
Journal: United European Gastroenterology Journal (2015)
Discipline: CLINICAL MEDICINE
Keywords: Colon; diverticular disease; diverticulitis; hemicolectomy; histology
Affiliations: Department of Medicine, University of Perugia School of Medicine, Perugia, Italy., Pathology Institute, Spedali Civili, Brescia, Italy., Department of Experimental Medicine, University of Perugia School of Medicine, Perugia, Italy., Department of Medical and Surgical Sciences, University of Brescia School of Medicine, Brescia, Italy., Department of Clinical and Experimental Medicine, University of Sassari, Sassari, Italy ; Baylor College of Medicine, Houston, TX, USA., Department of General Surgery, Galliera Hospital, Genova, Italy., Department of Pathology, Galliera Hospital, Genova, Italy., Department of Clinical and Experimental Medicine, University of Sassari, Sassari, Italy., Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy., Hospital of Baselland, University of Basel, Liestal, Switzerland.

Abstract:  Background: Diverticular disease of the colon is frequent in clinical practice, and a large number of patients each year undergo surgical procedures worldwide for their symptoms. Thus, there is a need for better knowledge of the basic pathophysiologic mechanisms of this disease entity. Objectives: Because patients with colonic diverticular disease have been shown to display abnormalities of the enteric nervous system, we assessed the frequency of myenteric plexitis (i.e. the infiltration of myenteric ganglions by inflammatory cells) in patients undergoing surgery for this condition. Methods: We analyzed archival resection samples from the proximal resection margins of 165 patients undergoing left hemicolectomy (60 emergency and 105 elective surgeries) for colonic diverticulitis, by histology and immunochemistry. Results: Overall, plexitis was present in almost 40% of patients. It was subdivided into an eosinophilic (48%) and a lymphocytic (52%) subtype. Plexitis was more frequent in younger patients; and it was more frequent in those undergoing emergency surgery (50%), compared to elective (28%) surgery (p = 0.007). All the severe cases of plexitis displayed the lymphocytic subtype. Conclusions: In conclusion, myenteric plexitis is frequent in patients with colonic diverticular disease needing surgery, and it might be implicated in the pathogenesis of the disease. 

Retracted: No

PubPeer comments:
 Concerns exist over the fact that the paper fails to mention whether the authors have collected an informed consent from patients included in this study and the protocol was formally approved by an appropriate ethical committee or local IRBs. Indeed, it appears that patients samples were sent from various hospital to one single center but there is no mention whether this was pre-approved by any ethical committee. Could the authors provide these documents ? See the Method section here Methods Archival resection samples from the proximal resection margins of patients and controls were always analyzed according to a standard protocol. The proximal resection margin was chosen, in order to have a homogeneous standard and to avoid architectural distortions, due to the inflammatory process of diverticulitis. We obtained full-thickness sigmoid samples from formalin-fixed tissue and obtained transversal sections after paraffin embedding and processing for both conventional histological hematoxylin and eosin (H E) staining and immunohistochemistry (IHC). We assessed the presence of T lymphocytes by IHC, using the monoclonal mouse anti-human CD3 antibody (Dako Cytomation, Carpinteria, CA, USA) at a dilution of 1:40. , 
 the study was carried out according to ethical guidelines for retrospective studies using anonymized data ,