Improved wound healing with a modified electrosurgical electrode

5rrrrsh J01tmd ,I/ PklJ IiC Sur‘w.l t I99 I I, 44. 495499 1991 The Trustees of Rritlsh Associatton of Plastic Surgeons

Improved wound healing with a modified electrasurgical electrode P. E. M. Butler, C. Barry-Walsh,

B. Curren,

P. A. Grace,

M. Leader and D. Bouchier-Hayes

D~~urt~?lent.~~i.~ur~er~., P~~tht}~~~~and Anutnnz_r, Royal Colkge qf’ Surgeons in Ireland and ~euMrn{?nt H~~.~~~t~~~~ ~uh~~~l

SUMiWAR Y. Previous studies comparing standard electrosnrgical (ES) electrode and steel scalpel (SS) wound healing have reported poor initial tensile strength, a delay in reaching maximum tensile strength and an increased inflammatory response in the ES wounds. The hypothesis that a smaller needle (m~ifi~) electrode would give better wound healing than a standard electrode was tested. Using histology as a parameter of wound healing, incisions created by a modified electrode, a standard electrode and a steel scalpel were compared. Sixty Sha Sba mice were divided into 10 groups. Standardised dorsal skin incisions were made using steel scalpel, standard and modified electrosurgical cutting electrodes. Mice were sacrificed on days 0, 1,2,3,5,7,9,14,28 and 42. The incised skin was processed for standard and immuuohist~hemical staining. The standard ES wound had significantly higher numbers of poIymorphonuclear leukocytes in comparison to the SS and modified ES wounds (p < 0.01). However, ma~rophage numbers were found to be significantly lower in the ES wounds when compared to the SS wounds on days two and five (p < 0.05). The libroblast response was delayed by up to two days in the ES wounds when compared to the SS wounds. Epithelialisation was completed by day two in the SS and modified ES groups but was only complete by day three in the standard ES group (p < 0.01). These results show a histological response closer to that of the steel scalpel in the modified electrosnrgical wounds during wound healing when compared with the standard electrosnrgical wounds, and demonstrate the superiority of the modified electrode over the standard electrode.

Since their development in the 1920’s, eiectrosurgical instruments have consistently been associated with poor wound healing. excessive charring and inadequate control of the cutting electrode when compared to the surgical scalpel (Ward, 1925; McLean, 1929; Ellis. 19.71: Reid, 1939). Development of new oscillator units. capable of delivering a pure sinusoidal current with variable power output, in the late 1960s regenerated interest in electrosurgical cutting devices. Since then, studies comparing electrosurgery and scalpel incisions, have shown:

(1) Increased

inflammatory response in electrosurgical wounds, although the predominant cell or cellular make up of the inflammatory exudate was not identified (Glickman and Imber. 1970; Nixon et cri., 1975; Sozio c’t ~1.. 1975; Glover et al., 197X; Bellina t’t &., 1984; Sowa et ul., 1985), (2) Poor initial tensile strength in electrosurgical wounds when compared to steel scalpel wounds (Ellis. I93 I : Laurenson and Stephens. 1970; Pope, 197 I ; Gtover (~1ul., 1978), tensile strength in (3) Delay in reaching maximum electrosurgical wounds when compared to steel scalpel wounds (Pope, 197 1; Glover rt 01.. 1978). However, studies comparing the histology of wound healing after eiectrosurgical cutting electrode and scalpel blade incisions have not been reported previously. Similarly, studies comparing healing in wounds using ~1standard and a smaller sized electrosurgical cutting electrode have not been undertaken. The present study was therefore initiated to compare

histologically the healing of incised wounds produced by a standard electrosurgicai cutting electrode, a modified electrosurgical cutting electrode and ;1 steel scalpel.

Materials and methods E.uperimmtul

animal

Sixty adult Sha Sha mice weighing between 24 and 28 grams were used for these experiments. This species ofmouse is a hairless mutant which is homozygous for the shaven gene, hence the name Sha Sha (Flanagan and Isaacson, 1987). The skin of these mice contains poorly developed hair follicles and is
equipment

The electrosurgical device used in these experiments was an “Electrocise” unit (Research and Development, Dublin). This unit delivered a~tern~~tin~ current at a frequency of 3.5 megahertz and voltage of 650sI 100 volts to the cutting electrode. The cutting electrodes used were a standard electrosurgical cutting electrode (Concept, Inc., USA; Tech-Switch electrode, No. 9 166), and a needle or “modified” tlectrosurgical cutting electrode (Coles Electrosurgical, C’levDent, USA ; Incising, Type E-l -A 1(Fig,. 1). A SwannMorton number 15 scalpel blade was used to create the scalpel incisions. The voltage setting of the Electrocise unit was determined pre(~pe~~itivel~ on an

British Journal of Plastic Surgery

496

Figure l-Photograph of cutting modalities. Left to right; standard electrode (2.5 mm cutting tip), modified electrode (0.35 mm cutting tip) and scalpel blade (Swarm-Morton number t 5).

anaesthetised test animal for both the standard and modified electrosurgical cutting electrodes.

The incised wounds and adjacent tissues were examined using immunohistochemical and standard histological staining. The standard histological stains used were haematoxylin and eosin and Mallory’s trichrome stain. Two immune-histochemical stains were also used: (1) a monoclonal antibody specific for mouse macrophage (Seralab, MAS 034B) counterstained by a secondary antibody immunoperoxidase technique (Springer et af., 1978)and (2) a rabbit anti-human Van Willebrand factor antibody (Dakopatts A082 /128) counters~ained by a secondary antibody immunoperoxidase technique (Sehested and Hou-Jensen, 1981). All mouse tissue specimens from day 0 to day 42 were stained with haemotoxylin and eosin. Specimens from days 7-42 were stained with Mallory’s trichrome stain which stains immature or maturing collagen, so to identify the healing scar. Specimens from days l-9 were stained with the mouse macrophage immunohisto~hemi~al stain. Specimens from days 1-21 were stained with the factor VIII immunohist~hemical stain which stains endotheliat ceffs. Histologicai counting and examination

Experimental method

The mice were divided into 10 groups of 6 mice each and were sacrificed on days 0, 1, 2, 3, 5, 7, 9, 14, 21, and 42 post-operatively. The animals were anaesthetised with a modified face mask using a mixture of 4% halothane and oxygen, at a flow rate of 3 L per minute at induction. Anaesthesia was maintained throughout the experiment using a mixture of 2% halothane and oxygen at a flow rate of 3 L per minute. The anaesthetised mouse was placed prone on the electrosurgical earth plate and its back was cleaned with O.So/, chlorhexidine solution. Using a perspex grid to limit depth and length of the wound four transverse dorsal skin incisions 2 cm apart and 5 mm in length were made (Fig. 2). The first incision was made with the standard electrosurgical cutting electrode, a second with the modified electrosurgical cutting electrode and two others with the steel scalpel (Fig. 2). The type of incision at each particular site was varied randomly. I MODI~ED

I

ST!B_

1

SCALPEL

ELETCI’ROSURGICAL I I 1 SCAJ..PEL

I

STANDARD ELJXTROSURGICAt

I ,~~~L~E Fig. 2 Figure Z-Incisions

used on the dorsum of mouse.

Specimens from day 0 and day 42 were examined under low power magnification (X10) and the transverse diameter of the wounds was measured and tabulated using a counting graticule (EIIA, Graticules Ltd, England). All specimens stained with haematoxylin and eosin from days O-7 were examined under high power magni~cation (X40) and using the mounting graticufe the polymorphonu~l~ar leukocytes were counted in three sites in relation to the wound; at the base and on either side. Specimens stained with the mouse macrophage immunohistochemical stain were examined under a high power field counting graticule in three fields and the cells present were counted and tabulated. Specimens stained with the factor VIII immunohistochemical stain were examined using the counting graticule at high power magnification, the numberof fibroblasts (identified as blue spindle shaped cells) and the &apillary~endotheliaI cells (brown staining) present in three standard high power fields were counted. All specimens stained with haemato~yli~ and eosin from day 0 to day 5 were examined under medium power magnification (X20) and the percentage epidermal covering of the wound was measured using the counting graticule. The epidermal migration across the wound was given one of four percentage gradings, Oo/ lOO,&SO%, 100%. All data are presented as mean 2 standard deviation. Results were tested for statistical significance in all cases using the Student’s t-test except epidermaf response which was tested using the MannWhitney U-test (a test of statistical significance for non-parametrically distributed data). Statistical significance was taken as p < 0.05. Results

Initial and healed wound defects

The initial epidermal defect was 0.60 f 0.07 mm in the

Improved Wound Healing with a Modified Electrosurgical Electrode steel scalpel (SS) wound, 0.64&0.04 mm in the modified electrode (ME) group and 0.74 k 0.03 mm in the standard electrode (SE) group. The healed epiderma1 defect at 42 days stained with Mallory’s trichrome stain was found to be smallest in the SS wound 0.09 + 0.03 mm. larger in the ME group 0.3+0.05 mm and largest in the SE group 0.7 +0.03 mm (Fig. 3). Differences between SS. ME, and SE in the initial and healed incisions were statistically significant (pound The polymorphonuclear leukocyte response in the wound in the SS group peaked between days 1 (42 _+9) and 2 (35 + 7), falling to near normal by day 3 (11 k 5). The ME group showed elevated values on days 1 (60 ? 9) and :I (58 -+_9) but fell towards normal by day 3 (10 5 4). The SE values. however, were markedly elevated in comparison to the other two cutting modalities on days 1 (86 t_ 7), 2 (84-t 4), 3 (78 ? 6) and remained elevated up until day 5 (lOf4) (Fig. 4). Differences 0.8

0.6

0.4

0.2

0.0

Healed

p-: 0.01

vs steel scalpel and standard

+ p < 0.01 m 0 0

The macrophage response in the wound in the SS group was greatest on days 2 (9 f 5) and 3 (8 it_7) falling at day 5 (5.5 _t 6) returning to norrnal by day 7 ( I .5 k 3). Both electrosurgical wounds had responses on day 2 (ME; 5.3+5: SE; 625). day 3 (ME; 717: SE: 7+6). and day 5 (ME: 1.7+2: SE; 1.8+1.9) which were lower than the SS wound values. Differences between the SS and the electrosurgical groups were found to be statistically significant on days 2 and 5 (pGO.05) (Fig. 5). Fihrohlmt

response in the healing ~twntl

The fibroblast response in the SS wound began by day 3 (70 + 14) and reached a maximum between days 5 (137 + 17) and 7 (106 k 12), falling by day 9 (9X k 27) to resting values by day 14 (69 f 18). The response was delayed in both of the electrosurgical groups. the highest values in these groups being reached between day 7 (ME; 118224: SE; 137kl6) and day 9 (ME; 108+ 12: SE; 129? 13) and fell to normal by day 14 (ME; 88 i 14: SE; 96 _t9). Differences between SS and SE groups, between SS and ME: groups and between SE and ME groups were smtistically significant on days 7 and 9, and between SS ;~nd SE groups onday 14(p
l_-_L

E -: : 5 n

between the SS and SE groups, between SS and ME groups and between SE and ME groups on days I and 3 and between the SE group and SS on day 3 were %und to be statistically significant (p 5; 0.01 1(Fig. 4).

Epithelial cell migration across the heulinq ~~*omd

Epidermal migration began by day 1 In Al wounds but was significantly delayed in the SE wounds (p
electrode

vs steel scalpel

Modified Electrode Standard Electrode Steel Scalpel

Fig. 3 Figure 3 modaLtie\

Inltu

and healed wound defects

in the three

cutting

Discussion Numerous studies comparing steel scalpel and electrosurgery incisions have shown an increased inflamma-

0 Modified Electrode + Standard Electrode + Steel Scalpel

0

1

2

3

4

D Modified + Standard

Electrode Electrode

5

Day 0 * p < 0.01

t p c 0.01

vs steel scalpel and standard

2

4

Fig. 5

Fig. 4 leukocyte

8

’ p < 0.05 vs steel scalpel

vs steel scalpel

Figure 4 ~-~Polyntorphonuclear wound Vrom days 0 5.

6

Day

electrode

response

In the healing

Figure So--Macrophage 1.

response

in the healrng

w.>,und from days I

498

* % u 6 5 2 z’

British Journal of Plastic Surgery

0 Modified Electrode + Standard Electrode + Steel Scalpel

120loo806040

, 2

0

4

/ 6

, 8

, / , , , 10 12 14 16 18 20 Day

’ p ~0.01 vs steel scalpel and standard electrode + p < 0.0 1 vs steel scalpel

Fig. 6 Figure CFibroblast 21.

response in the healing wound from days l-

+ Modified Electrode Standard Electrode

0

2

1

3

Day * p < 0.0 1 vs steel scalpel and modified electrode

Fig. 7 Figure 7-Epidermal

response in the healing wound from days O-3.

tory response in the electrosurgery wounds, although the predominant cell present was not identified (Glickman and Imber, 1970; Nixon et al., 1975; Sozio etal., 1975; Glover etal., 1978; Bellina et al.. 1984; Sowa et al., 1985). In the present analysis we have demonstrated that the polymorphonuclear leukocyte is the predominant cell in the inflammatory response associated with electrosurgical wounds. The numbers of polymorphonuclear leukocytes were lower in the modified electrosurgical wounds than in the standard electrosurgical wounds, but both electrosurgical wounds had significantly higher numbers of polymorphonuclear leukocytes when compared to the steel scalpel wounds. Simpson and colleagues demonstrated that a lack of polymorphs does not adversely affect wound healing (Simpson and Ross, 1972). However, if they are present in large numbers they can delay wound healing by causing premature clot lysis (RamStrom, 1984). Surprisingly, the macrophage, the other cell normally present in the acute inflammatory exudate, was found in significantly lower numbers in the electrosurgical wounds. Whether, in general, the proliferation of polymorphs could inhibit the appearance or migration of macrophages in a healing wound is speculative; nevertheless, this would appear to have occurred in the electrosurgical wounds. Macrophage

infiltration always precedes the onset of fibroplasia and is essential for the process of wound healing. Studies in monocytopenic guinea pigs have shown a significant delay in fibroplasia, collagen formation and wound healing (Dieglemann et al., 1981). In the present study the fibroblast response in the electrosurgical groups was found to be delayed, possibly secondary to the depressed macrophage response seen in the electrosurgical wounds. This delay in fibroplasia may explain the previously reported poor initial tensile strength and delay in reaching maximum tensile strength of electrosurgical wounds (Ellis, 1931; Laurenson and Stephens, 1970; Pope, 1971; Glover et al., 1978). The epidermal migration rate was found to be significantly delayed in the standard electrosurgical wounds when compared to the steel scalpel and modified electrosurgical groups. The present investigation shows that modified electrosurgical wounds have a histological response closer to that of steel scalpel wounds than standard electrosurgical wounds and suggests that incisions created by the modified electrode heal better than those resulting from the standard electrosurgical electrode. The findings of this study suggest that the steel scalpel is better than cutting electrodes as a pure cutting modality. However. as a cutting electrode the modified electrode is significantly better than the standard electrosurgical electrode. Nonetheless, electrosurgery has many advantages over the scalpel. These include : reduction or elimination of foreign material from the wound (i.e. ligatures) (Ellis, 1931; Gloveret al., 1978),reductioninoperating time (D’Arsonval, 1891; Glover et al., 1978), reduction in post-operative pain (Ellis, 1931), sealing of lymphatics in excision of malignant tumours (Mayo, 1925 ; Glover et a/., 1978) and reduced distortion of tissues when cutting (Butler, 1972). The present analysis suggests that a modified electrosurgical electrode may have certain advantages over standard electrosurgical electrodes. More recently the increasing incidence of diseases transmitted by blood such as HIV and hepatitis B makes electrocautery an attractive alternative to scalpel dissection as it reduces or eliminates blood from the operative field. The use of electrosurgery as a cutting tool in both emergency and elective situations has obvious advantages in reduction of health risks to medical personnel and we suggest that the modified electrosurgical electrode may be the instrument of choice in these situations. Acknowledgement I wish to thank Professor during this project.

N. P. Butler

who provided

assistance

References Bellha, J. H., Hennings, R., Voros, J. and Ross, L. (1984). Carbon dioxide laser and electrosurgical wound study with an animal model: a comparison of tissue damage and healing patterns in peritoneal tissue. American Journal ofObstetrics and Gynecology, 148,327. Butler, N. P. (1912). The principles and application oj high,fkequenc> electrical current in conseroatiw dentistry. Report of the meeting of teachers of conservative dentistry of Great Britain and Ireland.

Improved -----Wound Healing

with

a Modified

Electrosurgical

Electrode

D’ Arsonval, A. ( 189 I ). Action physiologique descourants alternatifs. Com~tc,s rendus Societe BioIogique. 43. as cited in : Glover, J. L., Bendick. P. J. and Link. W. J. (1978). The use of thermal knives m surgery: Flectrosurgery. lasers and plasma scalpel. Currr~nt Prohlemr m Surgrr~,. 1, I Diegelmann. R. F., Cohen, I. K. and Kaplan, A. M. (1981). The role of macrophages m wound repair: a review. P[ostic uncl Reconstruc111C Surgery, 68, 107. Ellis, J. I). ( I93 I ). The rate of healing of electrosurgical wounds as expressed by tensile strength Journal of the Amrrrcon Medrccrl Avwcrc~ron. 96. 16. Flanagan, S. P. and Isaacson, J. H. (1987). Close linkage between genes which cause halrlessnesa in the mouse. Journml of Gen~trcnl Rtwarch

Comhridge.

9. 99.

Glickman, 1. and Imber, L. (1970). Comparison of gingival resection with electrosurgery and periodontal knives-a biometric and histological study. Journal of Periodontologl,. 41, 147. Clover, J. L.. Bendick, P. J. and Link, W. J. (1978) The use of thermal kmves in surgery: Electrosurgery. lasers and plasma scalpei. Currenf Prohlrms in Surger.p. 1, 1. Laurenson, K. B. and Stephens, F. 0. (I 970). The use of electrocuttmg and electrocoagulation in surgery. Australian and ,Yew Zealand Journul of Surgery, 39.417. Mayo. W. J. (I 925 ). The relative values of surgery and radiotherapy hlinnrrotn ,M&cine. 8. 7. as cited in : Williams, V. D. (1984). The healing of oral wounds. Journnlofthe American Demo1 Associntion. 108 1-, ?O.

McLean, A. J. (1929). The Bovie electrosurgical current generator. .Irchire.\ ol Surpry. 18. 1863. Nixon, K. C., Adkins, K. F. and Keys, D. W. (1975). HistologIcal evaluation of effects produced in alveolar bone following gingival Incision with an electrosurgical scalpel. Journal(?/‘Pf,riodonrolog,,. 46,40

Pope, J. W. !IS’il). Effect of electrosurgery on wound healing. Jrlurntrl o/ /he renne.ssee State Dental Association. 51, I8 28. as cited in: Williilms, V. D. (1984). The healing of oral wounds. Journcrlo/

the American

Dental Association,

108, 220.

Ramstrom, G. (1984). Contamination of oral wounds with saliva and bacteria Scandinavian JournalofHaemurology, 33,424. Reid, M. R. i 1939). Discussion of “The influence of control of haemorrhage and protection of delicate granulation tissue in wound healing”. Surgery, Grnrcolog)) and Obstetrics. 69, 155. as cited m : Glover. J. L . Bendick. P. J. and Link. W. J. (1978). The use of thermal knives in surgery: Electrosurgery, lasers and plasma scalpel. Current Problems in Surgery. 1, I. Sehested, M. and HowJensen, K. (1981). Factor VIII-related antigen as an endothelial cell marker in benign and malignant diseases.

499

__.

C’irchows Archives, 391, 217. as cited in Dakopatts Rabbit AntiHuman von Willebrand Factor Specification Sheet. Simpson, D. M. and Ross, R. (1972). The neutrophilic leucocyte in wound repair. A study with antineutrophll serum Journal o/ C‘linicol Imwtigation,

51, 1009.

Sowa. D. E., Masterson, B. J., Nealon. N. and Van Fraunhofer, J. A. (1985). Effects of thermal knives on wouml healing. Ohrrerrrcv ond Gpecology,

66.436.

Sozio, R. B., Riley, E. J. and Shklar, G. (1975) A histological and Non-filtered full electronic evaluation of electrosurglcal currents wavemodulated \q. filteredcurrent. Jotrrnmlol Prrkrfht,trc Dwti.\tr\,. 33, 300 Springer, T.. Galfre, G., Secher. D. S. and Milstein. C. (1978~. Monoclonal xenogenic antibodies to murine :ell ,,urface antigens: Identification of novel leukocyte differentiatior antlgens. Europvun Journnlqf Immunology. 539, as cited in Sera-Lab Data Sheet on monoclonal antibody against macrophag,: Ward, G. E. (193). Values of elcctrothermic methods in the treatment of malignancy. Journal (I/ the, 4 wcrwn Mrdinrl 4ssocrrrt;on. 84. 660.

The Authors P. E. M. Butler, BSc, MB, BAO, BCh(NUI). LRCP and LRCSlrel, Senior House Officer in Surgery, Beaumont llospital. Dublin. C. Barry-Walsh, MB, BAO. BCh, MRCPath. Senior Lecturer in Pathology, Department of Pathology, Royal Cl.1leg.e of Surgeons in Ireland and Beaumont Hospital. Dublin. B. Curren. FIMLS, Senior TechnicIan. Departmen . Bouchier-Hayes. Professor ot Surgery. Royal College of Surgeons 1n Ireland. Beaumont Hospital. Dublin. Paper received 9 May 1990. Accepted 17 April 1991 after revision.