Safety and efficacy of electrocautery scalpel utilization for skin opening in neurosurgery

Transcription

1 British Journal of Neurosurgery, June 2004; 18(3): TECHNICAL NOTE Safety and efficacy of electrocautery scalpel utilization for skin opening in neurosurgery B. SHEIKH Neurosurgery Department, King Faisal University, Saudi Arabia Abstract Diathermy is used widely in neurosurgical procedures, mainly for subcutaneous and deeper layers dissection. The use on scalp and skin of other body parts has been precluded by the fear of scar formation and wound dehiscence. One-hundred-andseventy-seven skin incisions for neurosurgical procedures have been performed using the micro-needle electrocautery scalpel (MES) and the steel scalpel. The elements in this study included: electrocautery generator unit, cutting mode, power, waveform, size and shape of the MES, depth of the incision, the speed of the electrode movement through tissue, amount of blood loss, physical inspection of the wound edges and wound complication. Patients tolerated the procedures well, with no increased risk from the use of the MES. Only two incisions had wound infection and dehiscence. All other patients had usual wound healing. Time taken during skin opening was significantly shorter when using the MES. Blood loss during skin opening was three to five times less when the micro-needle electrocautery scalpel was used. The MES is both safe and useful in neurosurgical procedures. The findings of this study recommend the use of the MES in all neurosurgical procedures, especially when blood loss has significant importance, such as in paediatric cases. Key words: Electrocautery scalpel, monopolar, neurosurgery, scalp incision, skin incision. Introduction The use of electrocautery in surgery dates back to 1909 when it was used to fulgurate tumours. 1 Later, in 1926, Cushing introduced it for neurosurgery use. 2 The general surgical use of electrocautery had been mainly reserved for incising and dissecting the subcutaneous tissue and deeper layers. The use of the electrocautery scalpel to open the skin in substitution for the classical steel scalpel has been rejected in the past for the fear of delay wound healing and the risk of infection. 3 Several reports reflected the recent change in this concept. The electrocautery knife has been used widely by general surgeons to create abdominal and thoracic incisions, with excellent results. The need for a fast and more haemostatic method to create incisions is even more important in neurosurgery, particularly for scalp incisions and in the paediatric age group. The present study evaluates the result of routine use of micro-needle electrocautery scalpel to perform skin incision in neurosurgical practice. Materials and methods The micro-needle electrocautery scalpel was used to perform 177 skin incisions during neurosurgical procedures. In each procedure, the proposed skin incision was marked and measured in millimetres. Each incision was then divided into two parts, one to be opened by the steel scalpel and the other half by the micro-needle electrocautery scalpel. The generator unit (Valleylab electrosurgical generator unit, Force FX-8C) was set on cutting pure mode, power of 5 W, and 390 khz sinusoid waveform. The microdissection needle tip (Colorado Biomedical, Inc.) was utilized as the electrocautery scalpel (Fig. 1). The size of the micro-dissection needle tip is 5 m. On completing total skin incision, the wound edges were inspected for physical differences between the parts performed by the steel scalpel and the micro-needle electrocautery scalpel. The total length and time taken to complete the incision on each side was calculated separately. The speed of skin incision was calculated in mm/s from the start of incising till completing the incision, including Correspondence: B. Sheikh, Neurosurgery Department, King Fahd Hospital of the University, PO Box 40040, Al-Khobar 31952, Saudi Arabia. Tel: (966) Fax: (966) bsheikh@helth.net.sa Received for publication 4 November Accepted 13 April ISSN print/issn X online/04/ # The Neurosurgical Foundation DOI: /

2 Electrocautery scalpel 269 FIG. 1. From right to left: micro-needle electrocautery scalpel, blade-tip monopolar, needle-tip monopolar and steel scalpel. haemostasis. The length in millimetres (mm) divided by the time in seconds gave the speed of incising movement (mm/s). The incision depth included the dermis, the epidermis and the superficial part of the subcutaneous layer. Only the tip of the micro-needle was allowed to come in contact with the proposed incision line, the sides were not allowed to touch the skin edges at any time. To avert the skin edges away as cutting proceeds, the surgeon and assistant applied mild traction pressure on either sides of the skin incision (Fig. 2). The variables evaluated in this study included: electrocautery generator unit, cutting mode, power, and waveform, size and shape of the electrode, depth of the incision, the speed of the electrode through the tissue, amount of blood loss, physical inspection of the wound edges and wound complication. Each wound was inspected on postoperative days 1, 3 and 14 for wound healing and complications. Results One-hundred-and-seventy-seven skin incisions were performed by or under direct supervision of a single neurosurgeon (BS), using the micro-needle electrocautery scalpel and steel scalpel. The reason for the neurosurgical operative intervention included: tumour, cerebrovascular malformation, aneurysm, depressed skull fracture, epidural haematoma, lumber and cervical disc herniation, ventriculo-peritoneal shunt, external ventricular drainage, spinal stenosis, thoraco-lumber spinal fracture-dislocation, compressive and traumatic peripheral nerve injury, neuro-endoscopic procedures, Arnold Chiari malformation and arachnoid cyst. The body distribution of the site of skin incision was: cranial 85 wounds, FIG. 2. Intraoperative photograph demonstrating skin averted by the surgeon and assistant to prevent wound edges contact with the shaft of the micro-needle electrocautery scalpel. abdominal 20 wounds, upper extremities 23 wounds, anterior neck 15 wounds, lumber trunk posterior midline and para-median 30 wounds, and four wounds on the antero-lateral thoraco-lumber trunk. Seventy-nine skin incisions were performed in patients in the paediatric age group (less or equal to 16 years) and 98 incisions in the adult age group. The depth of the incision included the dermis, the epidermis and the superficial part of the subcutaneous layer. The time calculated for the incision included neither fascia nor periosteum opening. The speed of skin incision was calculated in mm/s from the start of incising till completing the incision, including haemostasis. The speed of incision when the steel scalpel was used ranged between 0.17 and 0.37 mm/s, with an average of 0.3 mm/s. The speed of incision when the micro-needle electrocautery scalpel was used ranged between 1.8 and 2.5 mm/s, with an average of 2.3 mm/s. In comparison, a 10- cm skin incision using the steel scalpel would take an average of 5.5 min, while the same length incision using the micro-needle electrocautery scalpel would take an average of 45 seconds. The method of calculating blood loss utilizing both scalpel types was not accurate in milliliters or grams. Although this was a limitation, the number of gauze swabs and the size of blood staining on each gauze piece were measured. This averaged four times more on the side incised by the steel scalpel. The wound was inspected in each case immediately after completing skin incision by both scalpel and each half was compared. The comparison included the viability, colour, presence of charcoaling effect and dermal peeling. There was no macroscopic difference between the skin edges of the side incised by the steel scalpel and the other side by the micro-needle electrocautery scalpel (Fig. 3). Postoperative inspection on days 1, 3 and 14, did not

3 270 B. Sheikh FIG. 3. Intraoperative photograph immediately on completing skin incision. No macroscopic deference noticed between the two sides and no thermal burn effect seen. The micro-needle electrocautery scalpel was used to incise the right half and the left half was incised using the steel scalpel. reveal any difference in physical character. At 3 months follow-up visit the patients were questioned for any subjective notice of hair loss at the operative site. This was denied by both males and females adults, and by parents. Physical examination was performed to look for evidence of alopecia. On closeup inspection a minimal area of alopecia was noticed on the side performed by the micro-needle electrocautery scalpel (Fig. 4). Patients did not notice any difference in wound pain between the sides opened by the micro-needle electrocautery scalpel and the steel scalpel. Two patients had wound infection resulting in wound discharge and delay in wound healing. One had a lumber midline trunk incision for lumber microdiscectomy and the other had flank incision on the right iliac crest for bone graft harvest. The site of maximum wound dehiscence was checked. In the lumber wound, it involved the lower end of the wound (side opened by the micro-needle electrocautery scalpel). In the flank wound, it involved the middle part of the wound in which scalpel type side dehiscence started could not be identified. Both cases were treated successfully with appropriate antibiotics. Discussion The use of electrocautery in surgery involves the passage of high frequency electrical current through body tissue producing either a cutting or coagulation effect. 4 Currents up to 500 ma may then be safely passed through the patient. Heat will be produced wherever the current is locally concentrated. The high frequency current from the generator is FIG. 4. Temporal incision inspected three months after the operative procedure. No clinical evidence of alopecia seen. delivered to an active electrode held by the surgeon. When using monopolar electrocautery, the current is then spread through the body and returns to the generator via the patient s plate electrode. Modern equipment commonly used in surgery has cutting and coagulation modes with variable current inten-

4 Electrocautery scalpel 271 sities. Cutting mode involves the generator producing a continuous output, while coagulation mode involves a pulsed output. The blend facility only functions when in cutting mode and allows a combination of cutting and coagulation to increase the degree of haemostasis during cutting. 3 During use of the cutting mode, the passage of current into tissue cause cellular fluid to turn into steam, bursting cell wall and disrupting the structure. Although the use of electrocautery in surgery started in 1909, the instrument was only later introduced to neurosurgery use by Cushing in Several previous studies have investigated the use of electrocautery in skin opening. Most were concerning with general surgery and mainly for abdominal or thoracic skin incisions. These have shown that the use of electrocautery to create surgical wounds on the abdominal or thoracic regions does not increase the risk of wound dehiscence. 5 7 Allan et al. have studied the bursting stress of abdominal wounds incised by steel scalpel and diathermy cutting current. They found no significant difference in the mechanical strength of the wounds incised by either method. 5 Eisenmann et al. studied the healing process at the cellular level under electron microscope. They showed no differences between steel scalpel and electrocautery scalpel. 6 Furthermore, on clinical study, Kearns et al. have indicated that the electrosurgical scalpel has significant advantages over steel scalpel based on incision time, blood loss, early postoperative pain and analgesia requirements. 8 In a review on electrocautery and wound healing, Williams noted the articles reviewed were not giving similar information for unifying comparison and proper judgment on the validity and safety of the method. These included generator type and waveform, size and shape of the electrode, and the speed of the electrode movement through the incised tissue. 9 In the present study, detailed methodology is given to enable uniformity of comparison with previous or future investigation. Sozio et al. reported the size of the electrode tip to be mm and the speed of 1.27 cm/s. 10 They did not elaborate on the type of the generator unit, the cutting mode set, or the power generated. David et al. compared the haemostatic Shaw scalpel with the steel scalpel. 11 Their results indicated that the standard steel scalpel produced less damage. For the sake of comparison, the haemostatic Shaw scalpel should not be taken as a precise minimal electrocautery tissue interface. During the passage of the Shaw scalpel through the incised tissue, the whole length of the Shaw scalpel is in continuous touch along the sides of the skin wound causing prolonged electrocautery time for side effect. This means that theoretically the smaller the contact between the electrocautery electrode and the body tissue the less should be the electrocautery side effect. Butler et al. compared the effect of size 2.5 and 0.35 mm electrocautery electrodes on experimental animals. 12 They noticed the improved wound healing with the use of the modified smaller electrosurgical electrodes. This was also found by Farnworth et al. on another animal model. They compared microneedle electrocautery, standard-size needle and the Shaw scalpel. 13 The microneedle was found to cause less necrosis and very little tissue distortion as compared with the others. In this study, the microneedle electrocautery was the only size used. Papay et al. have studied the use of the microneedle scalpel and the steel scalpel. 14 However, there results concentrated on alopecia occurrence along the incision line and compared both electrocautery and the cold scalpel. They concluded that there was an adverse effect on the hair-bearing scalp region. In the present study we did note the presence of an area of alopecia that was noticed by the treating neurosurgeon on clinic follow-up, but none of the patients had a direct complaint in this regard. Groot et al. studied wound infection rate in cases of abdominal or thoracic wounds and compared the electrocautery and steel scalpel. 7 They found that electrocautery does not increase the wound infection rate. In neurosurgical practice, the acceptable rate of infection is 1%. 15 In the present study, two wounds out of the 177 incisions were complicated by infection and dehiscence, giving a rate of wound infection among this study group to be 0.011%. This is well within acceptable range of neurosurgical wound infection rate, indicating no increase rate of wound infection with the use of micro-needle electrocautery scalpel. Conclusion The micro-needle electrocautery scalpel is both safe and useful in neurosurgical procedures. The findings of this study support the use of the micro-needle electrocautery scalpel in all neurosurgical procedures, especially when blood loss forms a significant value such as paediatric cases. References 1 Garison FH. History of medicine. Philadelphia: WB Saunders Co., Fulton J. Harvey Cushing: the story of a great medical pioneer. Springfield: Charles C. Thomas publisher, Bovie WJ. New electrosurgical unit. Surg Gynecol Obstet 1928;47: Ulmer BC. Electrosurgical generator with instant response technology, Users guide. Colorado: Valleylab Co., Allan SN, Spitz L, van Noort R, Black MM. A comparative study of scalpel and electrosurgical incision on subsequent wound healing. J Pediat Surg 1982;17(1): Eisenmann D, Malone WF, Kusek J. Electrone microscopic evaluation of electrosurgery. Oral Surg 1970;29: Groot G, Chappell EW. Electrocautery used to create incisions does not increase wound infection rate. Am J Surg 1994;167: Kearns SR, Connolly EM, McNally S, McNamara DA, Deasy J. Randomized clinical trial of diathermy versus scalpel incision in elective midline laparotomy. Br J Surg 2001;88:41 4.

5 272 B. Sheikh 9 Williams VD. Electrosurgery and wound healing: a review of the literature. J Am Dent Ass 1984;108(2): Sozio RB, Riley EJ, Shklar GA. A controlled study of electrosurgical currents and wound healing. Oral Surg 1976;41(6): Sowa DE, Masterson BJ, Nealon N, von Fraunhofer A. Effects of thermal knives on wounds healing. Obstet Gynecol 1985;66: Butler PEM, Barry-Walsh C, Curren B, Grace PA, Leader M, Bouchier-Hayes D. Improved wound healing with a modified electrosurgical electrode. Br J Plast Surg 1991;44: Farnworth TK, Beals SP, Manwaring KH, Trepeta RW. Comparison of skin necrosis in rats by using a new microneedle electrocautery, standard-size needle electrocautery, and the Shaw hemostatic scalpel. Ann Plast Surg 1993;31(2): Papay FA, Stein J, Luciano M, Zins JE. The microdissection cautery needle versus the cold scalpel in bicoronal incisions. J Craniofac Surg 1998;9(4): Wilkins RH. Principles of neurosurgical operative technique. In: Wilkins RH, Rengachary SS, eds, Neurosurgery. McGraw- Hill companies, 1996:

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