Reaction of oral tissues to suture materials

Gilbert E. Lilly, Lieute,nmt Colonel, DC, liXA* UNITED STATES ARMY MEDICAL RESEARCH UNIT, PRESIDIO OF

SAN FRANCISCO, CALIF.

T here is currently available to the clinician a wide variety of suture materials for the closure of oral wounds. Although these materials have been evaluated previously in animals anal. in human beings, such investigations have involved the closure of wounds other than those of the oral cavity.l-I5 The vascularity of the oral tissues, the moist environment, and the associated bacterial flora of the oral cavity are unique and may alter the tissue response to the va,rious suture materials. As a result this response may differ from that reported in other anatomic sites.

The present study was undertaken to compare the reactions of the oral tis- sues to selected suture materials.

MATERIALS AND METHODS

Nine different commercially available suture materials were selected for this study (Table I). All sutures were of the 4-O size and were prepackaged in indi- vidual sterile containers.

Fourteen adult mongrel dogs served as the experimental subjects. The animals were placed under general anesthesia, and interrupted sutures were placed through the intact buccal mucosa and lateral border of the tongue with a half- circle cutting needle. A separate sterile needle was used for each suture. Nine sutures (one of each type) were placed in the buccal mucosa, and a corre- sponding number and type were placed in the tongue of each animal. The loca- tion of the different suture materials was varied at each anatomic site from one animal to another.

Animals were sacrificed, in groups of two, 1, 2, 3, 4, 6, 8, and 10 days postoperatively. At sacrifice, tissues were recovered by block section, fixed in formalin, and processed for histologic study. Multiple sections were cut at 5 microns and stained with hematoxylin and eosin.

All sections were examined microscopically without the examiner knowing the

*Chief, Oral and Maxillofacial Sciences Program.

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Oral tissue reactions to suture materials 129

Table I

SzL;ture material

iStee (monofilament) Nylon (monofilament) Surgical gut (plain) Chromic (medium) Polyester fiber (green braided) Dermal (black twisted silk) Cotton (white twisted) Silk (black braided) Linen (natural color)

Tissue response Total

1 Moderate ) Severe ,ivllmber of

Mild spedmm

18 (7.5%) 6 (25%) 24 18 (75%) 6 (25%) 24

9 (64%) 4 (29%) 1( 7%) 14

: (‘;:7; z4 $;:; ; i;y${ 19

5 (212) 12 (50;) 7 (292) z: 5 (19%) 6 (23%) 26 3 (12%) 6 (23%) 2 )i$j I( 4%) 3 (13%) 19 (834)

26 23

The figures in each column indicate the number of specimens judged representative for each response to each material. Percentages are based on the total number of tissue specimens available for each suture material. Suture materials are listed in the order of their comparative mean tissue response, based on the arbitrary values of 1, 2, and 3 assigned to “mild,” “moderate,” and “severe” responses.

Fig. 1. Moderate reaction in tongue associated with cotton suture, 3 days postoperatively. Circumscribed inflammatory infiltrate is primarily neutrophilic. (Magnification, x45.)

type of suture material used. The tissue reaction was arbitra,rily classified as mild, moderate, or severe, depending upon its intensity, nature, and extent.

RESULTS

In general, four tissue specimens were available for each suture material for each sacrifice date. In some instances, however, sutures were lost in the post- operative period, and gut sutures were not present at 8 and 10 days. The results of the microscopic examination are summarized in Table I. No observable dif- ferences were noted in the character of the tissue responses in the tongue and buccal mucosa,.

Specimens examined during the first three postoperative days revealed edema and an inflammatory infiltrate which was primarily neutrophilic (Fig. 1).

130 IA&~ O.S., O.M. & 02. July, 1968

Fig. 2. Mild reaction in buccal mucusa, associated with steel suture, 6 days postopera- tively. Mild inflammatory infiltrate is predominantly lymphocytir. (Magnification, x35.)

Pig. 3. Severe reaction associated with linen suture placed in tongue 6 days previously. Note diffuse, dense inflammatory infiltrate of neutrophils. (Magnification, x45.)

Lymphocytes and an occasional foreign-body giant cell were observed in some of the 3-day specimens. The reactions differed from one another in the extent and density of the cellular infiltrate. There was less consistency in the tissue response to specific suture materials in this early period than was observed in later speci- m.ens.

Mild and moderate reactions, observed 4 to 6 days after placement of sutures, consisted of an inflammatory infiltrate made up predominantly of lymphocytes and plasma cells (Fig, 2), Fibroblastic proliferation was evident in the milder reactions. Severe reactions were characterized by a dense, diffuse, cellular in- filtrate containing microabscesses (Fig. 3).

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Oral tissue reactions to suture materials 131

Pig. 4. Mild rea&ion, 8 days postoperatively, to nylon suture in buccal mucosa. Note sparse infiltrate of lymphocytes and plasma cells. IV, Space occupied by suture. (Magnification, x430.)

Fig. 5. Severe reaction in buti mucosa associated with silk suture, 8 days postoperatively. S, Space occupied by suture. Dense inflammatory infiltrate is predominantly neutrophilic. (Magnification, x430.)

Mild reactions, 8 to 10 days postoperatively, exhibited fibrosis and a sparse cellular infiltrate which was primarily lymphocytic (Fig. 4). Moderate reactions showed less fibrosis and a denser infla.mmatory infiltrate made up of plasma cells and lymphocytes. Severe reactions contained a dense diffuse inflammatory in- filtrate (Fig. 5). Microabscesses were observed in some specimens.

The reaction to the pkcement of steel and nylon sutures was definitely less than that associated with other materials. In no instance was the reaction asso- ciated with these materials judged to be severe.

In general, the tissue rea’ction associated with plain surgical gut was moderate

132 hilly O.R., o.IvI. & 02. J oly, 1968

t,o mild in nature, and there was no crvidence of oxccssive e(lcma. Kraction to plain gut could not be evaluated in X- and l&day specimens because the su- tures were absent. The reaction to chromic gut, although more intense than t,hat to plain gut, was judged severe in only 21 per cent of the specimens.

Reactions to polyester, dermal, cotton, and silk sut,ures were comparable in both severity and incidence. The tissue reaction to linen sutures wa.s consistently more severe than the reactions to other materials.

DISCUSSION

Although there wa,s some variation in the responses of the tissues to each suture material, there was sufficient consistency to make differences in the ma- terials readily apparent.

The milder tissue reaction associated with the monofilament suture materials was of particular interest. The favorable tissue response to steel and nylon sutures is similar to that reported for these materials in other anatomic sites.2p 6 There was a greater reaction to plain gut and chromic gut, but it was definitely milder than that observed with the multifilament mat,eria.l. These observations are in direct contrast to reports concerning the use of t,he same materials in other areas of the body.g-ll, 14, I5

The findings of this study indicate that the tissue reaction to the placement of sutures in the mouth is different from that seen at other locations. The milder reaction to the monofilament as compared to the multif?lament suture materials suggests t,hat the physical character of the suture material may be an important consideration in determining bhe tissue response when sutuses are used intra- orally. A possible expla.nation of this difference may be related to the transmis- sion of bacteria a,nd ora,l fluids into the depths of the wound by a wicking action which, theoretically, could be more active in multif2ament materials.

The responses to the various multifilament suture materials were not suffi- ciently different to be of practical clinica. value in determining suture accept- ability within this group, with t,he exception of linen, which consistently elicited more severe reactions.

SUMMARY

The comparative responses of oral tissues to nine different suture materials were evaluated histologically in the oral mucosa of dogs. Monofilament steel and nylon sutures produced the least reaction. Plain gut and medium chromic sutures resulted in greater tissue response than nylon and steel but considerably less than the multifilament materials studied. There was litt.le apparent difference among the multifilament materials, except for linen, which was consistently as- sociated with severe reactions.

The response of oral tissues to some intraoral sutures is considerably dif- ferent from that described for other anatomic sites. A possible explanation for this difference may be a wicking action which transmits bacteria and oral fluids into the wound.

The author wishes to express his appreciation for the excellent technical assistance pro- vided by Mr. James Armstrong in the preparation of the histologic material.

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REFERENCES

1. Britt, C. I., Miller, E. M., Felder, M. E., and Sirak, H. D.: Comparative Reaction of Mersilene and Silk Sutures Imnlanted Within the Heart. Ann. Burg. 153: 52-62. 1961.

2. Dettinger, G. B., and Bowers, W.’ F.: Tissue Response to brlon and Dacron Sutures: A Comparison With Nylon, Cotton, and Silk, Surgery 42: 325335, 1957.

3. Latimer, E. O., and Werr, J. A.: Clinical Experience With Dacron as a Nonabsorbable Suture Material, Burg. Gynec. & Obst. 112: 373-374, 1961.

4. Narat, J. IT., Csngelosi, J. P., and Belmonte, J. V.: Evaluation of Dacron Suture Ma- terial for General Surgery, Surg. Forum 3: 176-177, 1957.

5. Postlethwait, R. W., Floyd, B. J., Dillon, M. L., and Stowe, D. G.: Tissue Reaction to Blood Vessel Sutures, Am. Surg. 28: 799801, 1962.

6. Postlethwait, R. W., Schauble, J. F., Dillon, M. L., and Morgan, J.: Wound Healing. II. An Evaluation of Surgical Suture Material, Surg. Gynec. & Obst. 108: 555-566, 1959.

7. Postlethwait, R. W., Schauble, J. F., Dillon, M. L., and Freeman, J.: Wound Healing, Arch. Surg. 78: 958-961, 1959.

8. Shumacker, H. B., and Mandelbaum, I.: Clinical Evaluation of Dacron Suture Material, Arch. Surg. 83: 647-649. 1961.

9. Gaskin, Ey R., and Childers, M. D.: Increased Granuloma Formation From Absorbable Sutures, J. A. M. A. 185: 142-144, 1963.

10. Madsen, E. T.: An Experimental and Clinical Evaluation of Surgical Suture Materials. II, Surg. Gynec. & Obst: 97: 439-444, 1953.

11. Localio, 5. A., Casale, W., and Hinton, J. W.: Wound Healing-Experimental and Statisti- cal Study. V. Bacteriology and Pathology in Relation to Suture Material, Surg. Gynec. & Obst. 77: 481-492, 1943.

12. Large, 0. P.: Comparison of Tissue Reactions From New Sutures, Am. J. Surg. 69: 414-423, 1943.

13. Bellas, J. E.: Influence of Sutures Upon Operative Wounds, Ann. Surg. 112: 112-121, 1940.

14. Deterling, R. A., Jr., Coleman, C. C., Jr., Kee, J., and Humphreys, C. H., II: An Experi- mental Evaluation of Catgut as a Vascular Suture Material and a Report on Its Clinical Use. J. Thoracic Sure. 23: 303-326. 1952.

15. Howes, E. L.: The Strength of Wounds Sutured With Catgut and Silk, Surg. Gynec. fi Obst. 57: 309-317, 1935.