Gastrointestinal Surgical Techniques in Small Animals E-Book

• Herausgeber: John Wiley & Sons
• Kategorie: Fachliteratur
• Sprache: Englisch

Seitenzahl: 691

Veröffentlichungsjahr: 2020

Beschreibung

Gastrointestinal Surgical Techniques in Small Animals offers a highly detailed reference to surgical procedures in the gastrointestinal tract in dogs and cats. Each chapter describes the surgical techniques in depth, featuring high-quality illustrations depicting each step, and discusses tips and tricks for a successful surgery and potential complications. A companion website offers video clips demonstrating the procedures. Logically divided into sections by anatomy, each chapter covers indications, contraindications, and decision making for a specific surgery. Tips and tricks and potential complications are also covered. * Describes techniques for canine and feline gastrointestinal surgery in detail * Presents the state of the art for GI surgery in dogs and cats * Includes access to a companion website with video clips demonstrating techniques Gastrointestinal Surgical Techniques in Small Animals is an essential resource for small animal surgeons and veterinary residents.

Leseprobe

Table of Contents

Cover

List of Contributors

Preface

About the Companion Website

Section I: General Concepts

1 Gastrointestinal Healing

1.1 Anatomy

1.2 Phases of Wound Healing

1.3 Factors Affecting Gastrointestinal Tract Healing

References

2 Suture Materials, Staplers, and Tissue Apposition Devices

2.1 Suture Materials

2.2 Staplers, Linear, Circular, Skin Staples

References

3 Suture Patterns for Gastrointestinal Surgery

3.1 One‐ or Two‐Layer Closure

3.2 Tissue Inversion, Eversion, or Apposition

3.3 Stapled or Hand‐Sutured Anastomosis

3.4 Appositional Suture Patterns

3.5 Inverting Suture Patterns

3.6 Special Supplementary Patterns: Purse‐String

Bibliography

4 Feeding Tubes

4.1 Nasoesophageal and Nasogastric Tubes

4.2 Esophagostomy Tube

4.3 Gastrostomy Tube

4.4 Jejunostomy Tube

4.5 Gastrojejunostomy Tube

References

5 Drainage Techniques for the Peritoneal Space

5.1 Indications

5.2 Techniques

5.3 Tips

5.4 Complications and Aftercare

References

Section II: Oral Cavity

6 Maxillectomy and Mandibulectomy

6.1 Indications

6.2 Surgical Techniques

6.3 Tips

6.4 Complications and Post‐Operative Care

References

7 Glossectomy

7.1 Indications

7.2 Technique

7.3 Tips

7.4 Complications

References

8 Tonsillectomy

8.1 Indications

8.2 Technique

8.3 Tips

8.4 Complications

References

9 Palatal and Oronasal Defects

9.1 Indications

9.2 Surgical Techniques

9.3 Tips

9.4 Complications

References

10 Salivary Gland Surgery

10.1 Indications

10.2 Techniques

10.3 Tips

10.4 Complications and Outcome

Bibliography

Section III: Esophagus

11 Esophagotomy

11.1 Indications

11.2 Technique

11.3 Tips

11.4 Complications

References

12 Esophagectomy and Reconstruction

12.1 Indications

12.2 Technique

12.3 Tips

12.4 Complications

References

13 Cricopharyngeal Myotomy and Heller Myotomy

13.1 Indications

13.2 Technique

13.3 Tips

13.4 Complications

References

14 Vascular Ring Anomaly

14.1 Indications

14.2 Techniques

14.3 Tips

14.4 Complications and Aftercare

References

15 Hiatal Hernia

15.1 Indications

15.2 Techniques

15.3 Tips

15.4 Complications and Post‐Operative Cares

References

Section IV: Stomach

16 Anatomy and Physiology of the Stomach

16.1 Anatomy

16.2 Physiology

16.3 Acid Secretion and Gastrectomy

16.4 Stomach Motility and Gastrectomy

References

17 Gastrotomy

17.1 Indications

17.2 Techniques

17.3 Tips

17.4 Complications and Post‐Operative Cares

18 Gastrectomy

18.1 Indications

18.2 Technique

18.3 Tips

18.4 Complications and Post‐Operative Cares

References

19 Billroth I

19.1 Indications

19.2 Technique

19.3 Tips

19.4 Complications

References

20 Billroth II

20.1 Indications

20.2 Technique

20.3 Tips

20.4 Complications and Post‐Operative Care

References

21 Pyloroplasty

21.1 Indications

21.2 Technique

21.3 Tips

21.4 Complications

References

22 Roux‐en‐Y

22.1 Indications

22.2 Technique

22.3 Tips

22.4 Complications

References

23 Gastropexy

23.1 Indications

23.2 Surgical Procedures

23.3 Tips

23.4 Post‐Operative Care and Complications

References

Section V: Intestine

24 Enterotomy

24.1 Indications

24.2 Surgical Techniques

24.3 Tips

24.4 Post‐Operative Complications and Outcome

References

25 Enterectomy

25.1 Indications

25.2 Surgical Techniques

25.3 Tips

25.4 Post‐Operative Complications and Outcome

References

26 Enteroplication/Enteropexy for Prevention of Intussusception

26.1 Indications

26.2 Surgical Procedures

26.3 Tips

26.4 Post‐Operative Considerations and Prognosis

Bibliography

Section VI: Colon

27 Colectomy and Subtotal Colectomy

27.1 Indications

27.2 Surgical Techniques

27.3 Tips

27.4 Post‐Operative Considerations and Prognosis

References

28 Colotomy

28.1 Indications

28.2 Surgical Technique

28.3 Post‐Operative Considerations and Prognosis

References

29 Typhlectomy and Ileocecocolic Resection

29.1 Indications

29.2 Surgical Techniques

29.3 Tips

29.4 Post‐Operative Considerations and Prognosis

References

30 Colostomy and Jejunostomy

30.1 Indications

30.2 Surgical Technique

30.3 Tips

30.4 Post‐Operative Considerations and Prognosis

References

31 Colopexy

31.1 Indications

31.2 Surgical Techniques

31.3 Tips

31.4 Post‐Operative Care, Complications

References

Section VII: Rectum and Anal Sac

32 Approaches to the Rectum and Pelvic Canal

32.1 Indications

32.2 Surgical Approaches to the Rectum

32.3 Post‐Operative Care and Complications

References

33 Surgery of the Rectum

33.1 Indications

33.2 Surgical Techniques

33.3 Tips

33.4 Post‐Operative Care and Complications

References

34 Anal Sac Resection

34.1 Indications

34.2 Surgical Techniques

34.3 Tips

34.4 Post‐Operative Care and Complications

Bibliography

Section VIII: Liver and Gall Bladder

35 Liver Lobectomy

35.1 Indications

35.2 Technique

35.3 Tips

35.4 Complications

References

36 Surgery of the Gallbladder

36.1 Indications

36.2 Techniques

36.3 Tips

36.4 Complications and Post‐Operative Care

References

37 Biliary Diversion

37.1 Indications

37.2 Surgical Techniques

37.3 Tips

37.4 Complications

References

38 Surgery of the Bile Duct

38.1 Indications

38.2 Techniques

38.3 Tips

38.4 Complications

References

39 Biliary Stenting

39.1 Indications

39.2 Technique

39.3 Tips

39.4 Complications and Post‐Operative Care

References

40 Arterio‐Venous Fistula

40.1 Indications

40.2 Technique

40.3 Tips

40.4 Complications

References

41 Portosystemic Shunt

41.1 Indications

41.2 Technique

41.3 Tips

41.4 Complications

References

Section IX: Pancreas

42 Surgery of the Pancreas

42.1 Indications

42.2 Surgical Procedures

42.3 Tips

42.4 Post‐Operative Care and Complications

References

Index

End User License Agreement

List of Tables

Chapter 2

Table 2.1 Characteristics of suture materials used in digestive system proced...

Table 2.2 Suture, staple recommendations for GI surgery in small animals.

Chapter 6

Table 6.1 Indications for and comments on the different types of mandibulecto...

List of Illustrations

Chapter 2

Figure 2.1

Figure 2.2

Figure 2.3

Figure 2.4

Figure 2.5

Figure 2.6

Chapter 3

Figure 3.1

Figure 3.2

Figure 3.3

Figure 3.4

Figure 3.5

Figure 3.6

Figure 3.7

Chapter 4

Figure 4.1

Figure 4.2

Figure 4.3

Figure 4.4

Figure 4.5

Figure 4.6

Figure 4.7

Figure 4.8

Figure 4.9

Figure 4.10

Figure 4.11

Chapter 5

Figure 5.1

Figure 5.2

Figure 5.3

Figure 5.4

Chapter 6

Figure 6.1

Figure 6.2

Figure 6.3

Figure 6.4

Figure 6.5

Figure 6.6

Figure 6.7

Figure 6.8

Figure 6.9

Figure 6.10

Figure 6.11

Figure 6.12

Figure 6.13

Figure 6.14

Figure 6.15

Figure 6.16

Figure 6.17

Figure 6.18

Figure 6.19

Figure 6.20

Figure 6.21

Chapter 7

Figure 7.1

Figure 7.2

Figure 7.3

Figure 7.4

Chapter 8

Figure 8.1

Figure 8.2

Figure 8.3

Figure 8.4

Figure 8.5

Chapter 9

Figure 9.1

Figure 9.2

Figure 9.3

Figure 9.4

Figure 9.5

Figure 9.6

Figure 9.7

Figure 9.8

Figure 9.9

Figure 9.10

Figure 9.11

Figure 9.12

Figure 9.13

Figure 9.14

Figure 9.15

Figure 9.16

Figure 9.17

Figure 9.18

Figure 9.19

Chapter 10

Figure 10.1

Figure 10.2

Figure 10.3

Figure 10.4

Figure 10.5

Figure 10.6

Figure 10.7

Figure 10.8

Chapter 11

Figure 11.1

Figure 11.2

Figure 11.3

Figure 11.4

Figure 11.5

Figure 11.6

Figure 11.7

Figure 11.8

Chapter 12

Figure 12.1

Figure 12.2

Figure 12.3

Figure 12.4

Chapter 13

Figure 13.1

Figure 13.2

Figure 13.3

Figure 13.4

Chapter 14

Figure 14.1

Figure 14.2

Figure 14.3

Figure 14.4

Figure 14.5

Figure 14.6

Figure 14.7

Figure 14.8

Chapter 15

Figure 15.1

Figure 15.2

Figure 15.3

Figure 15.4

Figure 15.5

Figure 15.6

Figure 15.7

Figure 15.8

Figure 15.9

Figure 15.10

Figure 15.11

Figure 15.12

Figure 15.13

Figure 15.14

Figure 15.15

Chapter 16

Figure 16.1

Chapter 17

Figure 17.1

Figure 17.2

Figure 17.3

Figure 17.4

Chapter 18

Figure 18.1

Figure 18.2

Figure 18.3

Figure 18.4

Chapter 19

Figure 19.1

Figure 19.2

Figure 19.3

Figure 19.4

Figure 19.5

Figure 19.6

Figure 19.7

Chapter 20

Figure 20.1

Figure 20.2

Figure 20.3

Figure 20.4

Figure 20.5

Figure 20.6

Figure 20.7

Figure 20.8

Chapter 21

Figure 21.1

Figure 21.2

Figure 21.3

Chapter 22

Figure 22.1

Figure 22.2

Figure 22.3

Figure 22.4

Figure 22.5

Figure 22.6

Chapter 23

Figure 23.1

Figure 23.2

Figure 23.3

Figure 23.4

Figure 23.5

Figure 23.6

Figure 23.7

Figure 23.8

Figure 23.9

Figure 23.10

Figure 23.11

Figure 23.12

Figure 23.13

Figure 23.14

Figure 23.15

Figure 23.16

Chapter 24

Figure 24.1

Figure 24.2

Figure 24.3

Figure 24.4

Figure 24.5

Figure 24.6

Chapter 25

Figure 25.1

Figure 25.2

Figure 25.3

Figure 25.4

Figure 25.5

Figure 25.6

Figure 25.7

Figure 25.8

Figure 25.9

Figure 25.10

Figure 25.11

Figure 25.12

Figure 25.13

Figure 25.14

Figure 25.15

Figure 25.16

Figure 25.17

Figure 25.18

Figure 25.19

Chapter 26

Figure 26.1

Chapter 27

Figure 27.1

Figure 27.2

Figure 27.3

Figure 27.4

Figure 27.5

Figure 27.6

Figure 27.7

Figure 27.8

Figure 27.9

Figure 27.10

Figure 27.11

Figure 27.12

Chapter 28

Figure 28.1

Chapter 29

Figure 29.1

Figure 29.2

Chapter 30

Figure 30.1

Figure 30.2

Figure 30.3

Figure 30.4

Chapter 32

Figure 32.1

Figure 32.2

Figure 32.3

Figure 32.4

Chapter 33

Figure 33.1

Figure 33.2

Figure 33.3

Figure 33.4

Figure 33.5

Figure 33.6

Figure 33.7

Figure 33.8

Figure 33.9

Figure 33.10

Figure 33.11

Figure 33.12

Figure 33.13

Figure 33.14

Figure 33.15

Chapter 34

Figure 34.1

Figure 34.2

Figure 34.3

Chapter 35

Figure 35.1

Figure 35.2

Figure 35.3

Figure 35.4

Figure 35.5

Figure 35.6

Figure 35.7

Figure 35.8

Figure 35.9

Chapter 36

Figure 36.1

Figure 36.2

Figure 36.3

Figure 36.4

Figure 36.5

Figure 36.6

Chapter 37

Figure 37.1

Figure 37.2

Figure 37.3

Figure 37.4

Figure 37.5

Figure 37.6

Figure 37.7

Figure 37.8

Chapter 38

Figure 38.1

Figure 38.2

Figure 38.3

Figure 38.4

Figure 38.5

Figure 38.6

Figure 38.7

Chapter 39

Figure 39.1

Chapter 40

Figure 40.1

Figure 40.2

Figure 40.3

Figure 40.4

Figure 40.5

Chapter 41

Figure 41.1

Figure 41.2

Figure 41.3

Figure 41.4

Figure 41.5

Figure 41.6

Figure 41.7

Figure 41.8

Figure 41.9

Figure 41.10

Figure 41.11

Figure 41.12

Figure 41.13

Figure 41.14

Figure 41.15

Figure 41.16

Figure 41.17

Chapter 42

Figure 42.1

Figure 42.2

Figure 42.3

Figure 42.4

Figure 42.5

Guide

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Gastrointestinal Surgical Techniques in Small Animals

Edited by

Eric Monnet DVM, PhD, FAHA, DACVS, DECVS

Department of Clinical SciencesCollege of Veterinary Medicine and Biomedical SciencesColorado State UniversityFort Collins, CO, USA

Daniel D. Smeak DVM, DACVS

Department of Clinical SciencesCollege of Veterinary Medicine and Biomedical SciencesColorado State UniversityFort Collins, CO, USA

This edition first published 2020© 2020 John Wiley & Sons, Inc.

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, except as permitted by law. Advice on how to obtain permission to reuse material from this title is available at http://www.wiley.com/go/permissions.

The right of Eric Monnet and Daniel D. Smeak to be identified as the authors of the editorial material in this work has been asserted in accordance with law.

Registered OfficeJohn Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, USA

Editorial Office111 River Street, Hoboken, NJ 07030, USA

For details of our global editorial offices, customer services, and more information about Wiley products visit us at www.wiley.com.

Wiley also publishes its books in a variety of electronic formats and by print‐on‐demand. Some content that appears in standard print versions of this book may not be available in other formats.

Limit of Liability/Disclaimer of WarrantyThe contents of this work are intended to further general scientific research, understanding, and discussion only and are not intended and should not be relied upon as recommending or promoting scientific method, diagnosis, or treatment by physicians for any particular patient. In view of ongoing research, equipment modifications, changes in governmental regulations, and the constant flow of information relating to the use of medicines, equipment, and devices, the reader is urged to review and evaluate the information provided in the package insert or instructions for each medicine, equipment, or device for, among other things, any changes in the instructions or indication of usage and for added warnings and precautions. While the publisher and authors have used their best efforts in preparing this work, they make no representations or warranties with respect to the accuracy or completeness of the contents of this work and specifically disclaim all warranties, including without limitation any implied warranties of merchantability or fitness for a particular purpose. No warranty may be created or extended by sales representatives, written sales materials or promotional statements for this work. The fact that an organization, website, or product is referred to in this work as a citation and/or potential source of further information does not mean that the publisher and authors endorse the information or services the organization, website, or product may provide or recommendations it may make. This work is sold with the understanding that the publisher is not engaged in rendering professional services. The advice and strategies contained herein may not be suitable for your situation. You should consult with a specialist where appropriate. Further, readers should be aware that websites listed in this work may have changed or disappeared between when this work was written and when it is read. Neither the publisher nor authors shall be liable for any loss of profit or any other commercial damages, including but not limited to special, incidental, consequential, or other damages.

Library of Congress Cataloging‐in‐Publication Data

Names: Monnet, Eric, author, editor. | Smeak, Daniel D., author, editor.Title: Gastrointestinal surgical techniques in small animals / edited by Eric Monnet, Dan Smeak.Description: Hoboken, NJ : John Wiley & Sons, 2020. | Includes bibliographical references and index.Identifiers: LCCN 2019056768 (print) | LCCN 2019056769 (ebook) | ISBN 9781119369202 (hardback) | ISBN 9781119369226 (adobe pdf) | ISBN 9781119369233 (epub)Subjects: MESH: Digestive System Surgical Procedures–veterinary | Dogs–surgery | Cats–surgery | Surgery, Veterinary–methodsClassification: LCC SF911 (print) | LCC SF911 (ebook) | NLM SF 911 | DDC 636.089/743–dc23LC record available at https://lccn.loc.gov/2019056768LC ebook record available at https://lccn.loc.gov/2019056769

Cover Design: WileyCover Images: Courtesy of Eric Monnet

List of Contributors

Chad Lothamer, DVM, DAVDCDentistry and Oral SurgeryCollege of Veterinary MedicineUniversity of TennesseeKnoxville, TN, USA

Eric Monnet, DVM, PhD, DACVS, DECVSDepartment of Clinical SciencesCollege of Veterinary Medicine and Biomedical SciencesColorado State UniversityFort Collins, CO, USA

Jennifer Rawlinson, DVM, DAVDCDepartment of Clinical SciencesCollege of Veterinary Medicine and Biomedical SciencesColorado State UniversityFort Collins, CO, USA

Bernard Séguin, DVM, MS, DACVSDepartment of Clinical SciencesCollege of Veterinary Medicine and Biomedical SciencesColorado State UniversityFort Collins, CO, USA

Daniel D. Smeak, DVM, DACVSDepartment of Clinical SciencesCollege of Veterinary Medicine and Biomedical SciencesColorado State UniversityFort Collins, CO, USA

Preface

Small animal general surgery has evolved rapidly in the past decade. Procedures have become increasingly complex, including the expansion of minimally invasive surgery options. Gastrointestinal conditions requiring surgical therapy are very common in small animal practice. Therefore, we have created this gastrointestinal surgery textbook to serve as a current and comprehensive reference tool for general practitioners, surgery residents in training, and surgeons.

In this textbook, current techniques for gastrointestinal surgery are thoroughly described with detailed illustrations embedded in the text. With this in mind we chose to work closely with Molly Pullen (www.mborman.com) for her expert pen‐and‐ink illustrations. In addition, when necessary, surgical techniques are supplemented with intraoperative images.

For each technique described, tips are included by the authors to explain the surgeon's preferences among all the techniques depicted, and to give details to help the reader perform the procedures effectively. Our intent for adding tips was to allow chapter authors the ability to express their preferences in technique, many of which are not evidence‐based.

In this textbook we placed a strong emphasis on description of surgical techniques. We chose not to delve heavily in the pathophysiology or the diagnostic workup for the different surgical conditions mentioned because those topics are well described in other textbooks.

We would like to thank all the authors who assisted us during the arduous process of developing this new textbook. In the future, this textbook will be updated as needed to follow the progress and advances in veterinary gastrointestinal surgery.

About the Companion Website

Don’t forget to visit the companion website for this book:

www.wiley.com/go/monnet/gastrointestinal 

There you will find valuable material designed to enhance your learning, including:

Illustrations

Video clips

Scan this QR code to visit the companion website

Section IGeneral Concepts

1Gastrointestinal Healing

Eric Monnet and Daniel D. Smeak

Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA

The gastrointestinal tract heals as any other tissue in an orderly manner, with an inflammatory phase, a debridement phase, a granulation phase, and a maturation phase. However, there are some characteristics very specific to the gastrointestinal tract that sets it apart from other healing tissues.

The healing process of the gastrointestinal tract should not only re‐establish the anatomical integrity of the tract but also its function. Healing should happen with minimal scaring and stricture formation that could impede the motility of the gastrointestinal tract. Additionally, the formation of adhesions, even though rare in small animal surgery, could deteriorate gastrointestinal motility and should be minimized.

1.1 Anatomy

The wall of the gastrointestinal tract has a mucosa, a submucosa, a muscularis, and a serosa, except the esophagus and the distal rectum.

The mucosa has three distinct layers: the epithelium, the lamina propria and the muscularis mucosa. The lamina propria layer is made of vessels, lymphatics, and mesenchymal cells whereas the muscularis mucosa is a thin muscle layer. After completing the anastomosis, the mucosa heals very fast by epithelial cells migration over the defect providing a rapid barrier from the intestinal content. For intestinal healing to occur, a good surgical apposition of layers is required; everting or inverting patterns interfere with mucosal healing.

The submucosa layer, incorporating the bulk of the collagen, is the holding layer in intestinal surgery. Type I collagen (68%) predominates in the submucosa, followed by type III (20%) and finally collagen type V (12%) (Thornton and Barbul 1997). It is a loose connective tissue with lymphatic, nerve fibers, ganglia, and blood vessels that should be preserved during surgery. The muscularis layer consists of an inner circular muscle layer, a longitudinal outer muscle layer and collagen fibers. The serosal surface is made of connective tissue with mesothelial cells, lymphatics, and blood vessels. The serosa is important in the healing process because it helps prevent leakage of the gastrointestinal content in the immediate post‐operative period.

1.2 Phases of Wound Healing

1.2.1 Partial Thickness Injury

A partial thickness injury affecting only the mucosa or the serosa heals with epithelial cells and mesothelial cells proliferation without scaring. A full‐thickness trauma of the gastrointestinal tract results in an inflammatory reaction and a non‐epithelial cell proliferation that can result in scaring secondary to fibroblast activity (Thornton and Barbul 1997; Thompson et al. 2006).

1.2.2 Full‐Thickness Injury

As soon as the wall of the gastrointestinal tract is incised, hemorrhage occurs but it is rapidly controlled by an intense vasoconstriction. Following this initial phase, vasodilation occurs with migration of neutrophils, macrophages, platelets, and liberation of inflammatory mediators which characterizes the inflammatory phase. The platelets, by releasing diverse platelet‐derived growth factors (PDGF) and cytokines, contribute to hemostasis and cell recruitment like macrophages and fibroblasts. The neutrophils predominate during the first 24 hours but then macrophages become predominant past 48 hours following the initial injury. The macrophages play an important role in healing of the gastrointestinal tract by controlling local infection with phagocytosis, production of oxygen radicals, and nitric oxide. They also participate in debridement with phagocytosis and production of collagenase and elastase. The macrophages also regulate matrix synthesis and cell recruitment and activation. They release several growth factors (PDGF, transforming growth factor (TGFβ), fibroblast growth factor (FGF), IGF) and cytokines (TNFα, IL‐1) important for tissue healing. The macrophages recruit lymphocytes that liberate interleukin (IL‐6) and interferon (IFN) and promote angiogenesis with production of VEGF (Vasculogenic Endothelial Growth Factor). Finally, the capillary permeability is increased resulting in inflammation and edema on the edges of the incision that can persist for two weeks. Care should be taken initially when the sutures are placed to not induce tissue strangulation and necrosis. A fibrin seal develops over the serosa very quickly to provide a leakage protection of the surgical site (Pascoe and Peterson 1989; Thornton and Barbul 1997; Thompson et al. 2006).

Overlapping with the inflammatory phase is the debridement phase, with removal of injured tissue by macrophages. The debridement phase should not exceed 1–2 mm from the edges of the incision. During this process, collagen is resorbed by collagenase and synthesized by smooth muscle and fibroblast. The smooth muscles are the major contributor in collagen production within the gastrointestinal tract. The collagen degrade by the collagenase activity weakens the strength of the anastomosis. In the colon, the collagenase activity is increased over the entire length of the colon while in the small intestine, it is increased only at the site of the anastomosis (Hawley 1970; Jiborn et al. 1978a). The risk of dehiscence is high between 3 and 10 days after surgery. Usually, after 4 to 5 days, collagen synthesis is superior to lysis and the anastomosis regains strength. This collagenase activity can be increased by the amount of trauma induced by tissue manipulation at the time of surgery or the presence of a foreign body, and by the degree of contamination. The amount of collagen synthesized is affected by hypotension, hypovolemia, shock, and certain medications.

The granulation tissue appears at the beginning of the proliferative phase of intestinal healing. Fibroblast is the major cell type present past day 4 after surgery. The fibroblasts migrate under the control of PDGF, TGFβ and FGF. Fibroblast and smooth muscle lay down collagen fibers and new capillaries appear in the field.

After one to two weeks following the anastomosis, the epithelial layer is fully restored. The epithelialization of the anastomosis reduces the formation of excessive fibrosis tissue secondary to inflammation. The excessive fibrosis could lead to stricture formation. During the maturation phase, the collagen fibers are reorganized and the anastomosis is becoming thinner.

In summary, an intestinal anastomosis loses bursting strength during the first 3 to 5 days to finally regain 50–70% of the initial bursting strength in 2 to 3 weeks (Jiborn et al. 1978a, 1978b; Thompson et al. 2006; Munireddy et al. 2010).

1.3 Factors Affecting Gastrointestinal Tract Healing

1.3.1 Ischemia and Tissue Perfusion

Ischemia interferes with healing of any tissue and especially the gastrointestinal tract. The oxygen delivery to the peripheral tissue depends on the anatomy of the capillaries, vasomotor control, and oxygen saturation. The tissue perfusion depends on the amount of soft tissue trauma and especially trauma to the blood supply of the loop of intestine. The placement of tight sutures interferes with tissue perfusion and may increase the risk of dehiscence, especially in the colon and esophagus (Shikata et al. 1982; Chung 1987; Jonsson and Hogstrom 1992; Thornton and Barbul 1997). Hypovolemia and hypotension are critical factors that divert blood flow to essential organs, and oxygen delivery is also very important for collagen synthesis. A partial pressure of oxygen of at least 40 mmHg is required for collagen synthesis. During a hypovolemic event, the gastrointestinal tract downregulates its own blood flow. Anemia does not interfere with healing as long as the patient has a good cardiac output to compensate (Thompson et al. 2006).

1.3.2 Suture Intrinsic Tension

Incising oral and visceral tissues stimulate an initial vasoconstriction, followed by secondary vasodilation and increased vascular permeability mediated largely by kinins, ultimately causing edema and swelling of tissue edges. This should be kept in mind when tensioning suture lines or stitches because ischemic necrosis may develop as the suture strangulates the swelling tissue. In general, sutures in viscera of the digestive tract should be tensioned such that the incision edges are held firmly together without crushing or cutting through the needle purchase. When inverting suture patterns are used, the suture line is firmly tensioned such that the incised edges are fully inverted and minimal suture is exposed on the surface of the organ (Thornton and Barbul 1997).

1.3.3 Surgical Technique

A simple apposition of the submucosa of the gastrointestinal tract is desired to achieve primary healing because it is associated with the least amount of fibrous tissue and better function. An apposition of the submucosa is important for the rapid healing of the mucosa and preventing migration of microorganisms within the surgical site. An eversion or inversion of the mucosa has been shown to interfere with primary healing (Jiborn et al. 1978a, 1978c; Jansen et al. 1981; Ellison et al. 1982; Jonsson et al. 1985; Pascoe and Peterson 1989; Thornton and Barbul 1997). Stapled anastomoses are becoming commonplace in veterinary surgery (Hansen and Smeak 2015; Duell et al. 2016; Snowdon et al. 2016). Staples do not promote better healing of the gastrointestinal tract when sepsis or ischemia are present (Thornton and Barbul 1997). Sutureless anastomoses have been performed with devices working by compressing two inverted ring of bowel (Maney et al. 1988; Corman et al. 1989; Ryan et al. 2006; Bobkiewicz et al. 2017).

1.3.4 Nutrition

The nutritional support of the patient is paramount for the healing of the gastrointestinal tract. Malnourished patients are at increased risk for dehiscence. The addition of a feeding tube is very important to support the anorectic patient in the post‐operative period as the enterocytes are getting their nutrients mostly from the intestinal content traveling in the lumen. Vitamin A, C, and B6 are required for collagen synthesis. Iron and copper are also important for the cross‐linking of protein and tissue healing. The enteral nutrition is beneficial for the integrity of the gastrointestinal tract and prevent bacterial translocation (Thornton and Barbul 1997; Marks 2013).

1.3.5 Blood Transfusion

A blood transfusion has been associated with an increased risk of leakage after gastrointestinal surgery. It has been postulated that blood transfusion is affecting the inflammatory phase and the migration of macrophages (Apostolidis et al. 2000; Munireddy et al. 2010).

1.3.6 Local Infection

A local infection increases protease activity, which delays epithelialization because protease resorbs growth factors required for healing. A braided suture should be avoided even if they received an antimicrobial treatment as bacteria adhere to them more than to monofilament (Chu and Williams 1984; Masini et al. 2011). Polydioxanone seems to have the lowest affinity for bacteria (Chu and Williams 1984).

1.3.7 Intraperitoneal Infection

A septic peritonitis interferes with healing of an intestinal anastomosis because it reduces collagen content at the level of the anastomosis. The combination of bacterial and neutrophil collagenases increases the collagen fibers breakdown. The collagen synthesis and deposition are reduced by the peritonitis (Ahrendt et al. 1996; Munireddy et al. 2010). The septic exudate present in the anastomosis prevents synthesis and deposition of collagen and angiogenesis (Thornton and Barbul 1997).

1.3.8 Medications

In an experiment in rats, it was shown that the administration of methylprednisolone did not affect the mechanical strength of colonic anastomosis (Mastboom et al. 1991a). However, the effect of steroids on the healing of the gastrointestinal tract is controversial (Thornton and Barbul 1997; Thompson et al. 2006).

The administration of NSAIDs after gastrointestinal surgery is also very controversial (Mastboom et al. 1991b; Gorissen et al. 2012; Bhangu et al. 2014; Collaborative 2014). The non‐selective cyclo‐oxygenase inhibitors seem to increase the risk of leakage after colorectal surgery (Gorissen et al. 2012). Two meta‐analyses in human patients reported opposite results (Bhangu et al. 2014; Collaborative 2014). However, both of those studies have focused on colorectal surgery, which is not performed frequently in small animal surgery. In one of the studies, animal experiments were reviewed and showed that NSAID administration in the post‐post‐operative period increased the risk of leakage (Bhangu et al. 2014). The NSAIDs affect production of VEGF and angiogenesis. They also interfere with collagen formation and cross‐linking (Inan et al. 2006; Gorissen et al. 2012). After administration of NSAIDs, hydroxyproline concentration was significantly reduced after resection and anastomosis of the ileum. This effect was mostly present three days after surgery. Seven days after surgery, the concentration of hydroxyproline had risen again (Mastboom et al. 1991b). In a study on rats, NSAIDs increased the morbidity and mortality rates without necessarily leading to an increased risk of leakage (Mastboom et al. 1991b).

The chemotherapy drugs because of their immunosuppressant effect can negatively affect the healing of the gastrointestinal tract (Thornton and Barbul 1997).

1.3.9 Disease

There is very little evidence that diabetes interferes with gastrointestinal healing. In a rat model of diabetes, collagen synthesis was not affected. However, the bursting pressure of the intestinal anastomosis was reduced on day 3 after surgery, but this effect did not persist past day 7 (Verhofstad and Hendriks 1994; Thornton and Barbul 1997). Icterus has been shown to interfere with tissue healing (Bayer and Ellis 1976; Muftuoglu et al. 2005).

1.3.10 Large Intestine

The colon is considered by most surgeons as a rather “unforgiving” structure when it is incised and repaired, largely because of its unique healing qualities, and when leakage occurs, the results are often devastating to the animal (Williams 2012). An understanding of colonic healing is important, and incorporation of all the principles of repair are critical to reduce life‐threatening anastomotic dehiscence. Healing of the colon undergoes similar phases of wound healing to those found in the skin and other tissue layers but with a number of important differences (Agren et al. 2006). During the inflammatory phase, a fibrin clot forms over the site and, although this clot has minimal strength, it is important to achieve an early “seal,” and it is vital that it remains to act as a scaffold for fibroblast migration during the early repair phase. For the first three to four days, nearly all support for the colonic repair comes from the suture or staple line. Angiogenesis and migration of fibroblasts occurs and eventually replaces the fibrin clot scaffold during days 3 and 4. It is during this stage of repair that breakdown is most likely to occur (Williams 2012).

Although a fragile mucosal bridge also occurs within the first three to four days, depending on the size of the defect, substantive wound strength occurs only when local recruited smooth muscle cells and fibroblasts from the colonic submucosa and muscularis bridge the incision and begin producing collagen. Appropriate‐sized tissue bites are particularly important when repairing the colon because a zone of active collagen lysis occurs in a 1–3 mm zone immediately adjacent to the incised colon edge. The activity of matrix metalloproteases that cause collagen degradation peaks during the debridement phase through day 3 (Agren et al. 2006). Provided there is ample vascular supply after this time, collagen synthesis is accelerated, coupled with a rapid gain in wound strength. Aggressive tissue handling and excess contamination of the colonic wound can greatly increase the debridement activity at the sutured wound edge and this increases the risk of early tissue disruption, leading to dehiscence and leakage (Williams 2012). Return of strength at the healing site reaches about 75% of normal strength at four months after surgery, which is considerably slower than in the small intestine (Thornton and Barbul 1997). Surgeons can influence uncomplicated colonic healing by ensuring adequate tissue perfusion, eliminating any tension on the repair, accurately apposing colonic edges without inducing excess trauma, containing contamination, and avoiding increased intraluminal pressures by eliminating any distal obstruction (Holt and Brockman 2003; Williams 2012). Omental pedicle wraps have been advocated to reinforce the gastrointestinal repairs and support the local healing environment. Omentum may stimulate and augment angiogenesis and may also help maintain the vital fibrin clot and seal during the early phases of wound healing. The benefit of omental wraps in colonic surgery have not been proven in recent human clinical studies of colonic resection and anastomosis. However, most surgeons still recommend covering colonic repairs with omentum (Hao et al. 2008).

References

Agren, M.S. et al. (2006). Action of matrix metalloproteinases at restricted sites in colon anastomosis repair: an immunohistochemical and biochemical stud`.

Surgery

140 (1): 72–82.

Ahrendt, G.M. et al. (1996). Intra‐abdominal sepsis impairs colonic reparative collagen synthesis.

Am. J. Surg.

171 (1): 102–107; discussion 107–108.

Apostolidis, S.A. et al. (2000). Prevention of blood‐transfusion‐induced impairment of anastomotic healing by leucocyte depletion in rats.

Eur. J. Surg.

166 (7): 562–567.

Bayer, I. and Ellis, H. (1976). Jaundice and wound healing: an experimental study.

Br. J. Surg.

63 (5): 392–396.

Bhangu, A. et al. (2014). Postoperative nonsteroidal anti‐inflammatory drugs and risk of anastomotic leak: meta‐analysis of clinical and experimental studies.

World J. Surg.

38 (9): 2247–2257.

Bobkiewicz, A. et al. (2017). Gastrointestinal tract anastomoses with the biofragmentable anastomosis ring: is it still a valid technique for bowel anastomosis? Analysis of 203 cases and review of the literature.

Int. J. Color. Dis.

32 (1): 107–111.

Chu, C.C. and Williams, D.F. (1984). Effects of physical configuration and chemical structure of suture materials on bacterial adhesion. A possible link to wound infection.

Am. J. Surg.

147 (2): 197–204.

Chung, R.S. (1987). Blood flow in colonic anastomoses. Effect of stapling and suturing.

Ann. Surg.

206 (3): 335–339.

Collaborative, S.T. (2014). Impact of postoperative non‐steroidal anti‐inflammatory drugs on adverse events after gastrointestinal surgery.

Br. J. Surg.

101 (11): 1413–1423.

Corman, M.L. et al. (1989). Comparison of the valtrac biofragmentable anastomosis ring with conventional suture and stapled anastomosis in colon surgery. Results of a prospective, randomized clinical trial.

Dis. Colon Rectum

32 (3): 183–187.

Duell, J.R. et al. (2016). Frequency of dehiscence in hand‐sutured and stapled intestinal anastomoses in dogs.

Vet. Surg.

45 (1): 100–103.

Ellison, G.W. et al. (1982). End‐to‐end approximating intestinal anastomosis in the dog – a comparative fluorescein dye, angiographic and histopathologic evaluation.

J. Am. Anim. Hosp. Assoc.

18 (5): 729–736.

Gorissen, K.J. et al. (2012). Risk of anastomotic leakage with non‐steroidal anti‐inflammatory drugs in colorectal surgery.

Br. J. Surg.

99 (5): 721–727.

Hansen, L.A. and Smeak, D.D. (2015). In vitro comparison of leakage pressure and leakage location for various staple line offset configurations in functional end‐to‐end stapled small intestinal anastomoses of canine tissues.

Am. J. Vet. Res.

76 (7): 644–648.

Hao, X.Y. et al. (2008). Omentoplasty in the prevention of anastomotic leakage after colorectal resection: a meta‐analysis.

Int. J. Color. Dis.

23 (12): 1159–1165.

Hawley, P.R. (1970). Collagenase activity and colonic anastomotic breakdown.

Br. J. Surg.

57 (5): 388.

Holt, D.E. and Brockman, D. (2003). Large intestine. In:

Textbook of Small Animal Surgery

(ed. D. Slatter), 665–682. Philadelphia: Saunders.

Inan, A. et al. (2006). Effects of diclofenac sodium on bursting pressures of anastomoses and hydroxyproline contents of perianastomotic tissues in a laboratory study.

Int. J. Surg.

4 (4): 222–227.

Jansen, A. et al. (1981). The importance of the apposition of the submucosal intestinal layers for primary wound healing of intestinal anastomosis.

Surg Gynecol. Obstet.

152 (1): 51–58.

Jiborn, H. et al. (1978a). Healing of experimental colonic anastomoses. I. Bursting strength of the colon after left colon resection and anastomosis.

Am. J. Surg.

136 (5): 587–594.

Jiborn, H. et al. (1978b). Healing of experimental colonic anastomoses. II. Breaking strength of the colon after left colon resection and anastomosis.

Am. J. Surg.

136 (5): 595–599.

Jiborn, H. et al. (1978c). Healing of experimental colonic anastomoses. The effect of suture technic on collagen concentration in the colonic wall.

Am. J. Surg.

135 (3): 333–340.

Jonsson, T. and Hogstrom, H. (1992). Effect of suture technique on early healing of intestinal anastomoses in rats.

Eur. J. Surg.

158 (5): 267–270.

Jonsson, K. et al. (1985). Comparison of healing in the left colon and ileum. Changes in collagen content and collagen synthesis in the intestinal wall after ileal and colonic anastomoses in the rat.

Acta Chir. Scand.

151 (6): 537–541.

Maney, J.W. et al. (1988). Biofragmentable bowel anastomosis ring: comparative efficacy studies in dogs.

Surgery

103 (1): 56–62.

Marks, S.L. (2013). Enteral and parenteral nutrition. In:

Canine and Feline Gastroenterology

(eds. R.J. Washabau and M.J. Day), 429–444. St Louis: Elsevier.

Masini, B.D. et al. (2011). Bacterial adherence to suture materials.

J. Surg. Educ.

68 (2): 101–104.

Mastboom, W.J. et al. (1991a). Influence of methylprednisolone on the healing of intestinal anastomoses in rats.

Br. J. Surg.

78 (1): 54–56.

Mastboom, W.J. et al. (1991b). The influence of NSAIDs on experimental intestinal anastomoses.

Dis. Colon Rectum

34 (3): 236–243.

Muftuoglu, M.A. et al. (2005). Effects of high bilirubin levels on the healing of intestinal anastomosis.

Surg. Today

35 (9): 739–743.

Munireddy, S. et al. (2010). Intra‐abdominal healing: gastrointestinal tract and adhesions.

Surg. Clin. North Am.

90 (6): 1227–1236.

Pascoe, J.R. and Peterson, P.R. (1989). Intestinal healing and methods of anastomosis.

Vet. Clin. North Am. Equine Pract.

5 (2): 309–333.

Ryan, S. et al. (2006). Comparison of biofragmentable anastomosis ring and sutured anastomoses for subtotal colectomy in cats with idiopathic megacolon.

Vet. Surg.

35 (8): 740–748.

Shikata, J. et al. (1982). The effect of local blood flow on the healing of experimental intestinal anastomoses.

Surg Gynecol. Obstet.

154 (5): 657–661.

Snowdon, K.A. et al. (2016). Risk factors for dehiscence of stapled functional end‐to‐end intestinal anastomoses in dogs: 53 cases (2001–2012).

Vet. Surg.

45 (1): 91–99.

Thompson, S.K. et al. (2006). Clinical review: healing in gastrointestinal anastomoses, part I.

Microsurgery

26 (3): 131–136.

Thornton, F.J. and Barbul, A. (1997). Healing in the gastrointestinal tract.

Surg. Clin. North Am.

77 (3): 549–573.

Verhofstad, M.H. and Hendriks, T. (1994). Diabetes impairs the development of early strength, but not the accumulation of collagen, during intestinal anastomotic healing in the rat.

Br. J. Surg.

81 (7): 1040–1045.

Williams, J.M. (2012). Colon. In:

Veterinary Surgery Small Animal

, 2e (eds. K.M. Tobias and S.A. Johnston), 1542–1563. St Louis: Elsevier.