Review for 10.1186/s12876-015-0230-5 (2015)

Reviewer's report
Title:Closure of iatrogenic large mucosal and full-thickness defects of the
stomach with endoscopic interrupted sutures in in vivo porcine models: Are they
durable enough?
Version:3Date:2 November 2014
Reviewer: Chia-Yuan Liu
Reviewer's report:
Reviewer’s report:
Complete manuscript title: “Closure of iatrogenic large mucosal and full-thickness
defects of the stomach with endoscopic interrupted sutures in in vivo porcine
models: Are they durable enough?” By Kobayashi, M. and Sumiyama, K. et al
As authors described in the cover letter, this study was a preclinical study to
evaluate the feasibility of closure of endoscopic submucosal dissection (ESD) or
endoscopic full-thickness resection (EFTR) induced gastric wall defects with an
endoscopic suturing device (OverstichTM, Apollo Endosurgery Inc., Austin, TX)
in live porcine model. ESD and EFRT are both advanced skills for endoscopist.
New methods or devices for ESD or EFRT gain the popularity in the
gastroenterology community. OverstichTM is a curved-needle-based endoscopic
suturing device. It provide the chance to perform depth-control tissue
approximation. The goals for this study are feasibility and durability of
OverstichTM for ESD and EFRT induced gastric wall defects.
Base on the study design, the result provided evidence about feasibility of
OverstichTM for ESD and EFTR in live porcie model. However, the strength of
evidence for durability-related study between ESD and EFTR should be further
discussed. If there is no undesired complication, ESD induced gastric wall defect
only limited on the mucosal to submucosal layer. From the pathological point of
view, the lesion created by ESD is different from EFTR (from mucosa to serosa).
Major Compulsory Revisions
1. In page 7, line 4: Endoscopic suturing technique
#The absorbability of suture material was critical factor for durability and retention
of stich. What kind of suture material was using in the study? Was it absorbable
or non-absorbable?
2. In page 8, line 23-page 9, line2: first paragraph of Results and discussion
“In this study, all pigs survived for the one-week survival period. The successful
primary closure rate was 85.7% (12/14) in the post-ESD group (Figure 5) and
100% (3/3) in the post-EFTR group (p = 0.67; Figure 6). Except for two post ESD
ulcers in the first animal of this study, the primary defect closure was achieved in
all attempts.”
#Does the failure cases were all on the first animal of this study? Since feasibility
was the major target for this study, the author should address technical issue or
learning curve for OverstichTM. Meanwhile, the median procedure time in ESD
and EFTR were 15.5/74 min for 2/4 stiches. Was there any difference for
OverstichTM during these two lesions?
3. In page 9, line 20-21:
“However, minor abscesses and adhesions were observed in 2 of 3 animals
(66%) in the post-EFTR group.”
In page 14, line 7-9:
“Therefore, we believe that a device based on a curved stitching needle such as
used in this study is currently the best available tool to safely achieve EFTR.”
In page 14, line 11-12: Conclusion
“In conclusion, this animal study demonstrated the feasibility and safety of the”
#Although minor abscess may have chance to recovery after antibiotics
treatment, the safety issue after EFTR should be discussed.
4. Different spelling in the manuscript should be revised.
In page 4, line 8: OverstitchTM
In page 5, line 1: Overstitch
In page 7, line 5/6: OverStitch
In page 11, line 4: Overstitch
In page 20, line 3: OverstitchTM
Discretionary Revisions:
1. In page 11-12: the 4th and 5th paragraph of Results and discussion
#In Reference 15, Kantsevoy et al. had published a retrospective study with 12
patients. The feasibility in human with OverstichTM had been proved. In these
two paragraphs, the author had proposed some hypothesis for the discrepancy
between human and live porcine study. Pathological analysis for ESD/EFTR
lesion was only available in porcine study. It may provide better evidence for
supporting above these hypothesis.
2. In page 13, line 14:
“The divergence between post-ESD and EFTR closure outcomes in this study
clearly demonstrates that the form of tissue apposition (e.g. everted mucosa to
mucosa, inverted serosa to serosa, or multi-layered) is more relevant to suture
durability than other factors.”
#The author may add reference to support the discussion (the form of tissue
apposition is more relevant to suture durability than other factors).
Voermans, R. P. et al. Comparison of endoscopic closure modalities for
standardized colonic perforations in a porcine colon model. Endoscopy; 43(3):
217-22
3. If possible, please upload higher resolution of endoscopic photo (Figure
3,5,6,7,8).
Level of interest: An article of limited interest
Quality of written English: Needs some language corrections before being
published
Statistical review: No, the manuscript does not need to be seen by a statistician.
Declaration of competing interests:
I declare that I have no competing interests.