End-on extramucosal single layer suture with double anchoring in the submucosa on rabbits

SUTURA EM PLANO ÚNICO EXTRAMUCOSO COM ANCORAMENTO DUPLO DE SUBMUCOSA EM COELHOS

END-ON EXTRAMUCOSAL SINGLE LAYER SUTURE WITH DOUBLE ANCHORING IN THE SUBMUCOSA ON RABBITS

Luiz Roberto do Nascimento ²

Virgínio Cândido Tosta de Souza ³

Manuel de Jesus Simões ⁴

Eduardo Chibeni Fernandes Ramos ⁵

Félix Carlos Ocáriz Bazzano ⁶

Neil Ferreira Novo ⁷

Yara Juliano ⁸

Paulo de Oliveira Gomes ⁹

Nascimento LR, Souza VCT, Simões MJ, Ramos ECF, Bazzano FCO, Novo NF, JulianoY, Gomes PO. End-on extramucosal single layer suture with double anchoring in the submucosa on rabbits. Acta Cir Bras [serial online] 1999 Apr Jun; 14(2). Available from: URL: http://www.scielo.br/acb

SUMMARY: The techniques of gastrointestinal surgical sutures have been frequently focused in controversial publications. These ones concern not only anastomosis’ types but also about thread types and how to apply them.

The values of the submucosa as layer of greatest resistence of the digestive tube was already known since the past century.

The aim of this study is to avaluate the suture in an extramucosal single-layer suture with double anchoring of the submucosa, a technical detail not found in the searched literature.

This experiment was carried out using 36 white,male adults New Zealand, rabbits divided into three groups which differed only regarding day of re-operation and euthanasia, as followed: group I ( 4 days), group II (7 days) and group III ( 15 days).

Two transversal and parallel gastrotomies were perfomed in the same animal, one distal and other proximal, of with 4 cm extension each. In these gastrotomies two types of sutures were alternated : 1- End-on extramucosal single-layer suture and 2- End-on extramucosal single-layer suture, with double anchoring in the submucosa.

Macroscopic and microscopic studies were perfomed on the suture line in both gastrotomies and in each period of euthanasia.

Except for the serosa item whose results were similar for both sutures, statiscally, the extramucosal single-layer suture, with double anchoring of submucosa layer showed better macro and microscopic results than the extramucosal single-layer suture in group I (4 days). In the others periods of euthanasia (groups II and III), the statistical results were similar.

SUBJECT HEADINGS: Suture techniques. Stomach. Rabbits

INTRODUCTION

Since the beginning of surgery, suture techniques used in the digestive tube have been focused on in many studies and controversial publications. These divergence regards to the most variable details, such as: disposition of stitches (suture), anastomosis techniques, type of threads used, distance between the stitches and between the surgical wound border among others.

HALSTED (1887) was the first investigator who argued against the double- layer suture, when he showed in the small intestine of a dog that the second layer, pressing the first, was harmful to blood circulation , because it promoted necrosis in the anastomosis area. He also was the first investigator to emphasize the importance of the submucosa as being the layer of greatest resistance of the gastrointestinal tunicae. He postulated that the sutures should be hermetic, anchored in the submucosa and performed with a fine thread; stitches should not be perforating and should be made in an extramucosal single layer.

These principles remained forgotten for decades, until GORODICHE and JOURDAN (1951), reviewing these hypothese proposed to perform sutures in extramucosal single layer with juxtaposition of the borders. Several clinical and experimental studies in the following decades confirmed the good performance of the single- layer suture. (GAMBEE, 1956 and Van GEERTRUYDEN, 1960; HEIFETZ, 1966; BRONWELL, RUTLEDGE, DALTON JR, 1967; LETWIN and WILLIAMS, 1967; REICHEL, 1968; ORR, 1969).

In Brazil ,ALMEIDA in 1971, modified the GAMBEE suture. FARIA in 1972 in a PhD thesis experimentally showed the advantages of a extramucosal single- layer suture over the double- layer suture. This study was a mark in the national literature and called the attention of many Brazilian surgeons to the importance of this type of suture, thus contributing to the diffusion of this technique.

Based on the principles of the single- layer suture and on the properties of the submucosa we decided to carry out this research in which a double anchoring is performed in the submucosa.

METHOD

White, male, adult New Zealand rabbits (Oryctolagus cuniculus) identified by numbering from 01 to 36, tattooed on the internal face of the right ear and weighing ranging from 2,800g to 3,240g were used.

The rabbits were fed with a specific ration until 48 hours before surgery when feeding was discontinued. Twelve hours before the procedure water was also discontinued.

They were divided into three groups according to time of re-operation and euthanasia:

GROUP I (GI) - 12 animals re-operated on the 4 ^Th. postoperative day.

GROUP II (GII) - 12 animals re-operated on the 7 ^Th. postoperative day.

GROUP III (GIII) - 12 animals re-operated on the 15 ^Th. postoperative day.

PROCEDURES

Anesthesia was done with intramuscular premedication of 2 mg/kg body weight acepromazine, 30 minutes prior to anesthesia with 4mg/kg body weight xylazine associate with 40 mg/kg body weight ketamine, both intramuscularly.

The rabbit was then placed in a horizontal dorsal decubitus on the surgical table and its paws fixed to the extremities of the table with thin ropes.

Hair from the regio abdominis cranialis and media, at the site of surgery, were clipped close to the skin with an electric device.

Antisepsis of the surgical site was performed with 2% iodinated alcohol solution and the surgical area was demarcated with sterilized fields.

Medial laporotomy was performed, starting 1 cm below the processus xiphoideus following a caudal direction until completing a 5 cm extension. Inspection of the peritoneal cavity was systematically performed during which the stomach was identified and exteriorized from the peritoneal cavity.

Two types of sutures were performed:

1- Extramucosal single-layer suture with juxtaposition of the borders and separated stitches (suture A), according to figure 1.

2- Extramucosal single-layer suture with double anchoring in the submucosa, with juxtaposition of the borders also with separated stitches (suture B) according to figure 2. Both with 5-0 polypropylene thread, and a 1.5 cardiovascular needle cm. The knots were done in the serosal face, at a 3 mm distance from each other and 2 mm from the gastrotomy border.

Then, the ventriculi major curvatura was freed, 3cm from the pylorus (Figure 3)

The ventriculi minor curvature was freed for an extension of 2cm just below the arteria gastrica sinistra, both on the anterior and posterior face.

The anterior wall of the stomach was demarcated, by stitches, forming a quadrangle with 4 cm sides (Figure 3).

A 4cm gastrotomy at the distal demarcation (Figure 4) was performed and closed randomly with suture A or B. Afterclosing the distal gastrotomy (Figure 5), the same procedure was carried out in the proximal demarcation, thus, performing a proximal gastrotomy of equal extension which was closed with suture B( figure 6) when the distal gastrotomy was closed with the suture A and vice-versa.Thus, closing both gastrotomies (Figure 7).

The abdominal wall was closed in a single layer closure of the abdominal-wall with 000 cotton stitches was performed. The skin was closed in a similar way.

RE-OPERATION

The animals were re-operated on predetermined days of the postoperative period according to their respective group: GI, fourth days ,GII seventh days and GII fifteenth days of the postoperative period;.

Laparotomy was performed in the same way during the first surgical act, register of the peritoneal cavity was carried out giving a special attention to the gastrorrhaphy areas.

Next, the specimen was resected as monoblock removing the anterior wall of the stomach. The specimen was examined regarding presence of ulcer, coaptation of mucosa and serosa. Euthanasia of the animals was performed by intracardiac injection of 19.1% of 3 ml potassium chloride in the quantity.

The abdominal wall was closed using a technique similar to the first surgical act.

Histopathological of the tests were performed with sections perpendicular to the line of the suture including all structures of the gastric wall on both sides of the suture.

Five micrometer histological sections were stained using hematoxylin-eosin (HE). Histological test gave special attention to the presence of ulcer, aspect of coaptation of the mucosa, submucosa, muscular and serosa.

RESULTS

Comparison between proximal and distal gastrotomies separately, for sutures A and B, showed no statistically significant differences when in the proximal or distal sutures were performed. For this reason, the area was not considered and the results were presented jointly.

The asterisk above graph and after numbers means statistical significance.

Fig. 8 Graph representing the presence of ulcer between sutures A and B in the studied groups. Macroscopy.

Mc Nemar Test

GI A > B p = 0.0156 *

G II p = 0.3125

GIII p = 0.1250

Fig 9. Graph representing the a good coptation of the mucosa between the sutures A and B in studied groups . Macroscopy.

Mc Nemar Test

GI p = 0,0156 * A< B

GII results do not require analisys

GIII results do not require analisys

Fig. 10.Graph representing good coaptation of the serosa layer between the sutures A and B in the studied groups . Macroscopy.

Mc Nemar Test . results do not require analisys.

Fig. 11.Graph representing the presence of ulcer between sutures A and B in the studied groups. Microscopy.

Mc Nemar Test

GI p = 0,0156 * A> B

GII p= 0,3125

GIII p= 0,1250

Fig. 12.Graph representing a good + regular integration of the submucosa between the sutures A and B in the studied groups. Microscopy.

Mc Nemar Test

GI p = 0,0312 * A<B

GII p= 0,3125

GIII results do not require analisys

Fig. 13.Graph representing a good + regular integration of the muscular layer between sutures A and B in studied groups. Microscopy.

Mc Nemar Test

GI p = 0,0312 * A<B

GII p= 0,3125

GIII results do not require analisys

Fig 14. Graph representing a good + regular integration of the serosa between the sutures A and B in the studied groups . Microscopy.

Mc Nemar Test

GI p= 0,0625

GII p= 0,5000

GIII results do not require analisys

DISCUSSION

Many investigators showed that the method of border apposition influences to the process of epithelial repair (MELLISH, 1966; RAVITCH, CANALIS, WEINSHELBAUN and McCORMICK, 1967; JANSEN, BECKER, BRUMMELKAMP and KEEMAN, 1981).

Extramucosal single-layer suture, with juxtaposition of the borders, type A suture, described by GORODICHE & JOURDAN (1951) was chosen as the control group, with the following advantages: less exudative inflammatory reaction and an earlier and more intense fibroblast proliferation (FARIA, 1972).

Suture B was performed with double anchoring of the extramocosal submucosa, a technical detail not mentioned in the investigated literature. The theoretical objective of this supplementary point would be to perform a more effective approach of the tunicae, specially of the submucosa with the submucosa, rendering the suture more hermetic and resistant. The additional advantage would be that on performing a double anchoring, a second layer would be used without inconvinience of a double- layer suture such as overlapping of the layers and invagination of the borders.

NIGRO et al (1993) performed two 10 cm long seromuscular gastrotomies in a gastric body of dogs in order to study of two types of suture threads.

In the present study, two gastrotomies were also performed but with a complete section of all tunicae with 4 cm extension and with 4 cm distance from each other. Alternation of sutures A and B in the distal and proximal gastrotomies was performed in order that the frequency of each suture was the same in both gastrotomies.

With the objective to verify if the behavior of each of the sutures eventually depended on the proximal or distal position, a confrontation between the two areas were performed. This confrontation was separately performed for the A and B techniques. Exact Fisher’s test was applied, showing no differences in performing sutures in a distal or proximal position.

The statistical analysis showed that suture with double anchoring in the submucosa (suture B) had a better result on the fourth postoperative day when compared with an extramucosal single-layer suture (suture A) as concerns the following macroscopical items: presence of ulcer and coaptation of the mucosa. Regarding the item coaptation of the serosa, the result was statistically similar in both sutures.

The same analysis of the Groups II and III, regarding all the parameters studied showed no statistically significant differences between the sutures A and B.

In the statistical analysis of the microscopy results, the mode results labelled GOOD and REGULAR were incorporated in the same group because both represent similar cicatricial processes.

The results of the histological analysis followed the macroscopy results. Thus, a single-layer suture with double anchoring in the submucosa (suture B) presented a statistically significant better result than an extramucosal single-layer suture (suture A) when compared with each other in the Group I, reagrding to the following parameters: presence of ulcer, integration of the mucosa and integration of the muscular layer. Regarding the parameter integration of the serosa, the results were similar in both sutures. In Groups II and III the same comparisons performed as concerns all the parameters did not show differences.

No procedure similar to single-layer suture with double anchoring in the submucosa was found in the literature, thus not allowing comparison with these results.

The rabbit stomach presents delay in emptying and food residues are an aggressive factor regarding sutures since in some histological sections, both suture A and B, vegetal fibers were found between the tunicae of the gastric wall.

No methodology to quantify this finding and its frequency for each type of suture was applied sincethis was not within the scope of our study.

A great number of ulcers in sutures A and B was observed, being statistically greater in suture A of Group I which affected the healing process macro- and microscopically.

The presence of foreign body, devitalized tissues decrease collagen formation and extend the latent phase of healing (KHOURY et al., 1983, KORUDA & ROLANDELLI, 1990).

In this study, the finding of vegetal fibers between the sutured layers certainly also contributed to the delay in healing; however, we can not correlate this finding to the appearance of ulcers since such study was not carried out.

The only discordant variable between the two sutures was the double anchoring in the submucosa performed in suture B.

Macro - and microscopic analyses show that the healing process was impaired in the most internal layers of the gastric wall such as the mucosa, submucosa and muscular layer in the suture A. In the serosal layer this fact did not occur.

If we admit that double anchoring of the submucosa would render the suture more hermetic, not allowing entrance of a foreign body (vegetal fibers) between the sutured layers, we could explain why the more internal layers were impaired in the healing process, which did not occur with the serosa. We would also explain why in suture B, healing of the submucosa and muscular layer was similar in the studied groups. However, we can not prove this fact and therefore it is not clear due to which mechanism (s) suture B presented better results then suture A in group I.

CONCLUSIONS

1 - Extramucosal single-layer suture with double anchoring in the submucosa, presented better results than extramucosal single-layer layer on the fourth postoperative day .

2- Extramucosal single-layer suture with double anchoring in the mucosa presented similar results to extramucosal single-layer suture on the seventh and fifteenth postoperative day.

REFERENCES

Almeida AD. A modified single layer suture for use in the gastrointestinal tract. Surg Gynecol Obstet 1971; 132:895.

Bronwell AW, Rutledge R, Dalton Jr ML. Sigle layer open gastrointestinal anastomosis. Ann Surg 1967; 165:925-30.

Buchin R, Van Geertruyden J. Valeur comparée des sutures intestinales en un plan et en deux plans: etude experimentale et clinique. Acta Chir Belg 1960; 59:461-80.

Faria PAJ. Sutura gastro-intestinal em plano único extramucoso e em 2 planos, um total e um seromuscular invaginante: estudo experimental no cão [dissertação]. São Paulo: Escola Paulista de Medicina; 1972.

Gambee LP. A single layer open intestinal anastomosis applicable to the small as well as the large intestine. Western J Surg Obstet Gynecol 1951; 59:1-5.

Gambee LP. Tem years experience with a single layer anastomosis in colon surgery. Am J Surg 1956; 92:222-7.

Gorodiche J, Jourdan P. Anastomoses digestives en un plan de suture. Sem Hosp Paris 1951; 27:3740-7.

Halsted WS. Circular suture of the intestine: an experimental study. Am J Med Sci 1887; 94:436-61.

Heifetz CJ. Technique of single layer end-to-end intestinal anastomosis by triangulation. Surg Clin North Am 1966; 46:223-8.

Jansen A, Becker AE, Brummelkamp WH, Keeman JN. The importance of the apposition of the submucosal intestinal layers for primary wound healing of intestinal anastomosis. Surg Gynecol Obstet 1981; 152:51-8.

Khoury GA, Waxman B.P. Large bowel anastomose: I. The healing process and sutured anastomoses: a review. Br J Surg 1983; 70:61-3.

Koruda MJ, Rolandelli RM. Current research rewiew: experimental studies on the healing of colonic anastomoses. J Surg Res 1990; 48:504-15.

Letwin E, Wiliams HTG. Healing of intestinal anastomosis. Can J Surg 1967; 10:109-16.

Mellish P. Inverting or everting sutures for bowel anastomoses: an experimental study. J Pediatr Surg 1966; 1:260-5.

Nigro AJT, Hirota RT, Paula RM, Simões AGS, Vieira WTT. Estudo comparativo, em cães, das gastrorrafias feitas com fios de polipropileno ou de ácido poliglicólico. Acta Cir Bras 1993; 8:118-23.

Orr NWM. A single layer intestinal anastomosis. Br J Surg 1969; 56:771-4.

Ravitch MM, Canalis F, Weinshelbaun A, McCormick J. Studies in intestinal healing: III. Observations on everting intestinal anastomoses. Ann Surg 1967; 166:670-80.

Reichel K. Die einreihige enteroanastomose experimentelle und klinische ergebnisse. Langenbecks Arch Klin Chir 1968; 322:1005-11.

Nascimento LR, Souza VCT, Simões MJ, Ramos ECF, Bazzano FCO, Novo NF, JulianoY, Gomes PO. Sutura em plano único extramucoso com ancoramento duplo de submucosa em coelhos. Acta Cir Bras [serial online] 1999 Apr Jun; 14(2). Available from: URL: http://www.scielo.br/acb

RESUMO: As técnicas de sutura gastrointestinais sempre foram motivo de estudos e controvérsias na literatura. As divergências dizem respeito não só aos tipos de anastomose, mas também aos tipos de fios e ao modo de aplicá-los.

Desde o século passado o valor da submucosa como camada de maior resistência das túnicas do tubo digestivo já era conhecida.

O propósito desse trabalho é avaliar a sutura em plano único extramucoso, com ancoramento duplo de submucosa, um pormenor técnico não encontrado na literatura consultada.

O experimento foi realizado em 36 coelhos Nova Zelandia, brancos, adultos, machos, distribuídos em três grupos que diferiram entre si, só quanto ao dia da reoperação e eutanásia : grupo I (4dias); grupo II (7 dias ) e grupo III ( 15 dias).

Foram realizadas no mesmo animal duas gastrotomias transversais, uma proximal e outra distal, paralelas entre si e com 4 cm de extensão cada. Nessas gastrotomias foram alternadas dois tipos de suturas :1- sutura em plano único extramucoso, com ancoramento duplo na submucosa e 2- sutura em plano único extramucoso. Realizou-se estudos macroscópicos e microscópicos nas linhas de sutura de ambas gastrotomias e em cada período de eutanásia.

Com exceção do ítem serosa, cujos resultados foram semelhantes entre as duas suturas, estatísticamente a sutura em plano único extramucoso, com ancoramento duplo de submucosa, apresentou melhores resultados macro e microscópicos do que a sutura em plano único extramucoso, no grupo grupo I (4 dias). Nos demais períodos de eutanásia, grupos II e III, os resultados foram estatísticamente semelhantes.

DESCRITORES: Técnicas de sutura. Estômago. Coelhos.

Address for correspondence:

Luiz Roberto do Nascimento

Rua. Expedito da Silva Maia ,75

37550-000 Pouso Alegre – MG

Tel: [phone]-2531

e-mail: [e-mail].

Data do recebimento: 09/03/99

Data da revisão: 09/04/99

Data da aprovação: 05/05/99

1

¹

Summary of Master Thesis approved in the Post Graduation Course in Technical Surgery and Experimental Surgery of the UNIFESP-EPM – Federal University of São Paulo – Paulista School of Medicine, SP, Brazil oriented by the professor Doctor (PhD) Virgínio Cândido Tosta de Souza .

²

Master in Surgical Technique and experimental Surgery of UNIFESP-EPM

³

Doctor in Medicine of UNIFESP- EPM and Full Professor of the Department of Surgical Clinic - Pouso Alegre Medical School. M.G

⁴

Doctor and Professor of Department of Morfological Sciences UNIFESP- EPM .

⁵

Master in Surgical Technique and experimental Surgery of UNIFESP-EPM

⁶

Master in Surgical Technique and experimental Surgery of UNIFESP-EPM

⁷

Doctor and Professor of Biostatistic Division of Departament of Preventive Medicine of the UNIFESP-EPM.

⁸

Doctor and Professor of Biostatistic Division of Departament of Preventive Medicine of the UNIFESP-EPM.

⁹

Doctor in Medicine of UNIFESP- EPM and Professor of the Department of Surgical Clinic- UNIFESP- EPM.

Publication Dates

• Publication in this collection
  16 July 1999
• Date of issue
  Apr 1999

History

• Accepted
  05 May 1999
• Received
  09 Mar 1999
• Reviewed
  09 Apr 1999