Physical and Biological Properties of a novel Siloxane Adhesive for Soft Tissue Applications

Cosmetic Use of Octyl—2—Cyanoacrylate for Skin, Closure in Facial Plastic Surgery Dean M. Toriumi, M.D., Kevin O’Grady, Devang Desai, M.D., and Amita Bagal, M.D. Chicago, Ill. Octyl—2-cyanoacrylate is a long carbon chain cyanoac- rylate derivative that is stronger and more pliable than its shorter chain derivatives. One hundred and eleven pa— ‘ tients underwent elective surgical procedures by the same surgeon using either octyl-2—cyanoacry1ate or sutures for skin closure at the University of Illinois at Chicago. Most patients underwent excision of benign skin lesions with a mean wound size of 112 mIn3. Patients were randomized into either control (vertical mattress suture closure) or test groups (closure with octyl—2-cyanoacrylate). Surgical judgment was used to determine which wounds in each group required application of subcutaneous sutures to . relieve tension and aid in skin edge eversion. Generally, full-thickness (through dermis) wounds larger than 1 cm3 required the use of subcutaneous sutures. The time re- quired to close the epidermis with suture (mean, 3 min- utes and 47 seconds) was about four times that of octyl- 2—cyanoacrylate (mean, 55 seconds). Wounds were evaluated at 5 to 7 days for infection, wound dehiscence, or tissue reaction, and at 90 days using the modified Hol- lander wound evaluation scale. At 1 year, photographs of the wounds were evaluated by two facial plastic surgeons that graded the cosmetic outcome using a previously,val— idated visual analog scale. There were no instances of wound dehiscence, hema- toma, or infection in either group. Results of wound eval- uation at 90 days determined by the modified Hollander scale revealed equivalent cosmetic results in both groups. Results of the visual analog scale ratings showed scores of 21.7 i 16.3 for the 49 patients treated with octyl-2—cya— noacrylate and 29.2 : 17.7 for the 51 control patients treated with sutures. The lower visual analog scale score represented a superior cosmetic outcome at 1 year with the octyl—2-cyanoacrylate as compared with sutures. This difference is statistically significant at p = 0.03. Addition- ally, patient satisfaction was very high in the group treated with octyl—2-cyanoacrylate. (Plast. Reconstr. Surg. 102: 2209, 1998.) Precise approximation of skin incisions and lacerations with wound closure devices is criti- cal to a favorable cosmetic and functional sur- gical result. Principles of wound closure focus on relieving tension on the wound and bring- ing the skin edges together in an everted ori- entation.” Application of sutures requires pas- sage of a foreignmaterial through the skin that is usually left in place for 5 to 10 days. If sutures are tied too tight or left in. too long, they may leave permanent suture tracks.3 If sutures are removedbefore adequate healing, the lack of wound tensile strength may result in wound dehiscence or a widened scar. Although suture removal usually causes minimal discomfort, the procedure is often associated with increased patient anxiety. Additionally, suture removal in sensitive areas of the face, such as the nose, eyelids, and lips, can result in significant dis- comfort. New technology in surgical adhesives may provide the option of sutureless skin clo- sure. The ideal adhesive would: (1) be safe for topical application, (2) be easy to apply, (3) polymerize rapidly, (4) support the approxi- mated skin edges and maintain the skin edge eversion necessary for maximum wound heal- ing and acceptable cosmesis, and (5) eliminate the need for suture removal. The development of such technology, although useful for a vari- ety of surgical applications, including plastic surgery, would be of particular benefit in the treatment and follow—up care of pediatric pa- tients.“’5 Over the years, cyanoacrylates have been used for skin closure,“‘7 fixation of implants,“ tissue adhesion,4’5’8 closure of cerebrospinal From the Division of Facial Plastic and Reconstructive Surgery, Department of Otolaryngology—Head and Neck Surgery, University of Illinois at Chicago. Received for publication February 23, 1998; revised May 11, 1998. Presented in part at the Annual Fall Meeting of the American Academy ofFacial Plastic and Reconstructive Surgery, San Francisco, California, September 4, 1997. 2210 fluid leaksf’ and embolization of blood ves- sels.” In Europe and Canada, cyanoacrylate derivatives have been available as a surgical tissue adhesive for many years.5“7 Despite their availability, cyanoacrylate adhesives have failed to gain widespread popularity due, in part, to their suboptimal handling and application characteristics, variable outcomes, and the his- totoxicity associated with their use.”'13 The his- totoxicity associated with these materials is re- lated to the by-products of polymer degradation, length of the alkyl (R) group of the cyanoacrylate derivative, and the rate at which degradation occurs.“‘13 Degradation of the cyanoacrylate polymer yields the histotoxic by-products cyanoacetate and formalde- hyde.“'13 The shorter chain methyl—2—cyanoac- rylate and ethyl-2-cyanoacrylate derivatives de- grade at a faster rate than their longer chain counterparts, resulting in significant tissue tox- icity.“ Butyl—2-cyanoacrylate (Histoacryl, Braun, Germany), which has"/a four-carbon al- kyl constituent off the carboxyl group (COO- R), is approved for use in ,.Europe and Canada and is less toxic than methyl—2—cyanoacrylate and ethyl-2-cyanoacrylate because of its slower rate of degradation.” Octyl-2—cyanoacrylate (Dermabond, Ethicon Inc., Somerville, NJ.) was formulated to cor- rect some of the deficiencies of the shorter chain cyanoacrylate derivatives. As an eight- carbon alkyl derivative, the polymer should be less reactive than the shorter chain deriva- tives.“~13 The slower degradation of the octyl derivative may decrease the concentration of cyanoacrylate polymer by—products in sur- rounding tissues, resulting in less inflamma- tion. Additionally, plasticizers are used to pro- duce a stronger, more pliable, tissue- compatible end product that will flex with the skin and remain adherent for longer periods of time. Octyl-2—cyanoacrylate has a three-dimen- sional breaking strength that is three times that of butyl-2-cyanoacrylate.” Two recently published clinical studies ex- amined the external use of octyl-2—cyanoacry— late adhesive for superficial skin closure.15’16 Results of these studies showed no statistically significant difference in wound cosmesis be- tween wounds treated with octyl-2—cyanoacry- late and sutures.15=15 In our study, a prospective, randomized, controlled clinical trial was per- formed to determine if Octyl-2—cyanoacrylate is equivalent to standard suture skin closure. This study was performed as one arm of a multi- PLASTIC AND RECONSTRUCTIVE SURGERY, November 1998 institutional study with other centers in emer- gency medicine/ emergent care, dermatology, general surgery (hernia repair), obstetrics and gynecology (laparoscopic surgery), and ortho- pedic surgery. The University of Illinois at Chi- cago was the only facial plastic surgery center in the study. This study differs from the two previously published clinical studies on octyl-2- cyanoacrylate in that the same surgeon (DMT) performed all surgeries and long—term, 1-year follow-up photographs were obtained and an- alyzed to assess the final cosmetic outcomes. MATERIALS AND METHODS One hundred and eleven patients were ‘en- rolled and treated in an office minor surgical setting in facial plastic and reconstructive sur- gery according -to the guidelines of the Institu- tional Review Board of the University of Illinois at Chicago. Before study inclusion, a medical history and a review of recent and concomitant medications were performed. Patients were then evaluated on the basis of predetermined inclusion and exclusion criteria (Tables I and II‘). Those who successfully met and agreed to the study criteria and who read and signed the informed consent form were enrolled in the study. Using clinical indications as evaluated by the surgeon, patients were assigned to one of two treatment groups: (1) wounds with subcutane- ous sutures or (2) wounds without subcutane- ous sutures (Fig. 1). The primary criteria used to determine the need for subcutaneous su- tures are listed in Table III. Where appropri- ate, subcutaneous sutures (4-0 or 5-0 Polydiox- anone, Ethicon) were applied to aid in apposition of the wound edge margins, relieve tension, ensure adequate skin edge eversion, and prevent deposition of Octyl-2—cyanoacrylate TABLE I Enrollment Criteria Inclusion Criteria Exclusion Criteria Patients must: Patients presenting with: 1. Be at least 1 year of age 1. Significant multiple trauma 2. Be in good general health 2. Peripheral vascular disease with no significant systemic 3. Insulin—dependent diabetes abnormalities mellitus 3. Agree to return for follow-up 4. Blood clotting disorder visits 5. Personal or family history of keloid or hypertrophic scar formation 6. Known allergy to cyanoacrylate or formaldehyde Vol. 102, No. 6 / OCTYL—2-CYANOACRYLATE FOR SKIN CLOSURE A 2211 TABLE II Specific Wounds Excluded from the Study . Decubitus ulcers . Stellate lacerations Wounds on hair-bearing skin . Wounds from an animal or human bite Wounds with evidence of infection or rash . Wounds on mucosa or at mucocutaneous junctions . Wounds usually closed with 4-0 caliber suture or larger . Puncture wounds (other than punctures initiated from minimally invasive surgical procedures) ooxrmfitniapaww Patient Presen ts Patientliligible ‘ No———— Out Yes WounclEligib|e ‘ No-—-— Out Yes Physician Discretion No Subcutaneous Sutures 1 * L_.______/ Sutures octyl} i Sutures J Cy““°l‘“ V M J FIG. 1. Algorithm showing the method of randomizing patients into test and control groups. into the wound (Fig. 2, above). In some cases, wounds that could not be easily closed with 5-0—caliber skin sutures. were approximated with subcutaneous sutures to allow closure with 5-O—caliber (or smaller) sutures or octyl-2- cyanoacrylate. Subcutaneous sutures were rarely used in cases with partial-thickness wounds not penetrating through the dermis (Fig. 2, center and below). After appropriate as- signment, patients were randomized for skin closure into either the test group (octyl-2- cyanoacrylate) or the control group (sutures). Before surgical intervention, surgical sites were cleansed with an antiseptic agent and injected with local anesthesia (1% lidocaine TABLE III Criteria for Use of Subcutaneous Sutures Subcutaneous sutures are recommended for use when: 1. Subcutaneous dead space exists 2. The wound tendency is toward skin edge inversion 3. The wound is greater than 1 cm in length and/or greater than 1 cm in width 4. Tension on skin edges may prohibit easy closure with a 5-0 caliber suture 5. The depth of wound is beyond the depth of dermis (full- thickness) unless skin is thin (eyelid skin) with 1:l00,()00 epinephrine), The borders of the surgical site were marked with a marking pen, incisions were made, and the surgical de- fect was created (Fig. 3, above, left). Hemostasis was attained either by applying pressure or by using electrocauterization. Skin closure was performed based on patient randomization. Patients randomized to the control group, ei- ther with or without subcutaneous sutures, un- derwent vertical mattress skin closure with 5-0 or 6-0 nylon suture, whereas test patients, ei- ther with or without subcutaneous sutures, un- derwent skin closure using octyl-2-cyanoacry- late. In the test group without subcutaneous sutures, forceps were used to maintain skin edge eversion during application of the adhe- sive (Fig. 2, center, right). The adhesive was packaged in a sterile dis- posable blister pack that allowed easy applica- tion through a permeable tip after breaking th-einternal capsule containing the monomer. The adhesive was applied in multiple thin lay- ers over the incision site_._, v\n'th a 10- to 30- second delay between applications, to prevent pooling or running. Initial application of a thin layer of adhesive acted as a barrier, which minimized any heat dissipation to the tissues while polymerization, occurred. The adhesive was applied .n and around the incision, ex- tending,,5t/0010' mm beyond the incision, to ensure tissue stability (Fig. 3, above, right). Once completed, incision sites of the control pa- tients were treated with antibiotic ointment and covered with a bandage. Patients in the test group did not require an external bandage as the adhesive formed its own protective cov- ering (Fig. 3, below, left). The time required for epidermal skin clo- sure was recorded for both the test and control groups and only included the time required to apply the skin closure device (skin sutures or octyl-2-cyanoacrylate). This time did not in- clude application of the anesthesia, excision of the lesion, hemostasis or, where appropriate, application of the subcutaneous sutures be- cause these segments of the operations were independent of the method of epidermal skin closure. Patients in the control group were instructed to keep their wounds clean and dry before suture removal. Test patients were allowed to get their wounds wet, but they were asked to avoid soaking or scrubbing the surgical site. Patients were further instructed to allow the polymer to slough off from the wound site 2212 PLASTIC AND RECONSTRUCTIVE SURGERY, November 1998 FIG. 2. (Above, left) Everting subcutaneous suture used to take all tension off skin edges and evert wound after full-thickness incision through dermis. Note how the sutures are applied on the undersurface of the undermined dermal layer to obliterate all subcutaneous dead space and maximize eversion of the skin edges. (Above, right) Precise apposition of skin edges prevents subcutaneous deposition of octyl-2-cyanoacrylate. (Center, left) Partial-thickness skin incision or laceration with limited penetration of the dermal layer. Subcutaneous sutures are usually not necessary because there is limited separation of the dermis or subcutaneous tissues. (Center, right) Soft tissue forceps can be used to evert the skin edges while applying octyl-2-cyanoacrylate. (Below) Note how skin edge eversion can be achieved using octyl-2—cyanoacrylate without subcutaneous sutures. without assistance. Patients who received su- tures underwent suture removal at 5 to 7 days postoperatively. At each postoperative visit, wounds were examined for infection, inflam- mation, wound dehiscence or separation, and scarring. At the 90-day follow—up visit, the wounds were graded for cosmesis using the modified Hollander wound evaluation scale, which eval- uates six clinical categories, including step-off borders, contour irregularities, scar width, edge inversion, excessive inflammation, and overall cosmetic appearance of the wound.” For each patient, a score of 0 or 1 was assigned for each category. The six categories were then added together and a total score was recorded. A score of 0 reflected an optimal cosmetic outcome, whereas a score of 1 to 6 reflected a suboptimal cosmetic outcome. Wound evalua- tion scores of both the test and control groups were then compared to determine if any signif- icant difference was evident between wounds closed with sutures versus wounds closed with octyl-2—cyanoacrylate. A final long-term follow-up visit, at approxi- mately 1 year posttreatment, was also con- ducted. This additional long-term follow-up visit, which was not part of the multicenter or V0 2213 Vol. 102, No. 6 / ocm.-2—(:\ANoAcRY1A'rE FOR SKIN CLOSURE Flt}. (Above, lefl) Fusiform 2-cm defect created after excising facial lesion. (Above, righl) Application ofoctyl—2-cyanoaciylate to the opposed, everted skin edges after completion of subcutaneous closure. Multiple thin layers are applied, and the adhesive extends 5 to 10 mm beyon(l the incision to provide support. (Below, left) Octyl—2—cyanoac1ylate closure at end ofprocedure. Note that the polymer is clear and the wound can be visualized to assess for dehiscence or infection. (Below, right) One-year postoperative photograph ofsurgical scar after excision of benign skin lesion and closure with octyl-2-cyanoacrylate. Arrows point [0 SCAII Vol. 102, No. 6 / OCTYL—2-CYANOACRYLATE FOR SKIN CLOSURE ‘ 2213 FIG. 3. (Above, lefi) Fusiform 2-cm defect created after excising facial lesion. (Above, right) Application of octyl-2—cyanoacrylate to the opposed, everted skin edges after completion of subcutaneous closure. Multiple thin layers are applied, and the adhesive extends 5 to 10 mm beyond the incision to provide support. (Below, left) Octyl-2—cyanoacrylate closure at end of procedure. Note that the polymer is clear and the wound can be visualized to assess for dehiscence or infection. (Below, right) One—year postoperative photograph of surgical scar after excision of benign skin lesion and closure with octyl-2-cyanoacrylate. Arrows point to scar. 2214 protocol, required contacting all of the study participants by telephone or letter to schedule standardized studio photographs. A Nikon F3 camera body (Nikon, Tokyo, Japan) with a 105—mm lens and point flash was used for all photographs. The photographs were taken with 35-mm ASA 100 Ektachrome film (Kodak, Rochester, N.Y.) and were shot at a 1:1 and 1:2 magnification to provide good discrimination of the treatment site. The photographs were then given to two facial plastic surgeons that were unfamiliar with the study design, the purpose or site of the surgical incision, or the type of treatment re- ceived (sutures versus octyl-2-cyanoacrylate). Each surgeon was asked to rate the cosmetic results of the surgical sites using a visual analog scale by placing a mark along the scale that would correspond to the cosmetic out- come.15'“’V18 The wound cosmesis visual analog scale was based on a 100—mm line, with the best possible scar positioned at point 0 on the left side of the line and the worst possible scar positioned at the 100-mm point on the right side of the line. The score was then determined by measuring the distance in millimeters from point 0 to the recorded score. The mean score was determined for each patient to prow'de a quantitative subjective analysis of each wound. The wound cosmesis visual analog scale was used instead of the modified Hollander scale on the 1-year results to provide a completely nonbiased analysis by two individuals who spe- cialized in facial plastic surgery. Statistical Analysis The visual analog scale scores for both treat- ment groups were analyzed using analysis of variance (BMDP Statistical Software, 1nc., Los Angeles, Calif.). In a previous study, the l00—mm visual analog scale was validated.” Sta- tistical analysis was also performed on the dif- ferences in treatment time between the wounds closed with octyl-2-cyanoacrylate and sutures. RESULTS Of the 111 patients enrolled in the study, 57 patients (51.3 percent) were randomized into the control group, and 54 (48.7 percent) were randomized into the test group. The mean age of the patients studied was 41.2 years (range, 11 to 82 years), with no statistically significant difference in mean age between test and con- trol groups (test, 40.8 years; control, 41.6 PLASTIC AND RECONSTRUCTIVE SURGERY, November 1998 TABLE IV Patient Population (11 = 110) Ethnicity No. of Patients . Patient % Caucasian 69 62.7 African American 17 15.5 Asian/Pacific Islander 13 11.8 Hispanic 11 10.0 years). Table IV shows the ethnic breakdown of the patients who were enrolled in the study. In the control group, 34 patients (59.7 percent) required subcutaneous sutures, whereas 32 pa- tients (59.3 percent‘) received subcutaneous su- tures in the test group. The range in size (length >< width >< depth) of all wounds treated was 1 mm?‘ to 1350 mm3, with a mean wound size of -112 mm3. There was no statisti- cally significant difference in wound size be- tween treatment groups. Ninety—six percent of all procedures were confined to either the face or the neck, with the majority of patients un- dergoing excision of skin lesions (66.7 per- cent) and scar revisions (23.4 percent). After appropriate treatment, incision sites were closed according to patient randomization. The mean time for epidermal skin closure using suture (control) was 3 minutes and 57 seconds, whereas the mean time for epidermal skin closure using octyl-2-cyanoacrylate (test) was 55 seconds (Fig. 4). The total time for epidermal skin closure for both groups was 225.1 minutes, with 194.55 minutes (86.4 per- cent) devoted to suture closure of control wounds and 30.55 minutes (13.6 percent) for closure of test wounds with octyl-2-cyanoacry- late. Statistically, this difference in time for skin closure between octyl-2-cyanoacrylate and su- tures was significant (p < 0.0001). Time Required for Epidermal Skin Closure (Mear1_\_/$3.91- . . l i Octyi-2-cyanoacrylate i 1 Control (Sutures) 0 50 100 150 200 250 Time in Seconds FIG. 4. Time required for epidermal skin closure. Com- parison of time required using sutures (control) versus octyl- 2-cyanoacrylate (test). -u..-... Vo. Fit thc Or in! ity aft pa ho lO\ an er; ite are wi' tis wc an tic II]! de sit ra: of wt th 1.- C3 Cy Vol. 102, No. 6 / OCTYL-2—CYANOACRYLATE FOR SKIN CLOSURE Five- to Seven-Day Follow-up All 111 patients successfully returned for their 5- to 7-day postoperative follow—up visit. One control patient presented with a localized inflammatory reaction resulting from sensitiv- ity to the antibiotic ointment that was applied after suture placement. Additionally, one test patient reported an inflammatory reaction 48 hours posttreatment. However, at_ the early fol- low—up visit, there was no evidence of infection and the wound healed without sequelae. Sev- eral of the wounds closed with sutures exhib- ited increased inflammation and erythema around the incision site, whereas those closed with octyl-2-cyanoacrylate had significantly less tissue reaction. There were no instances of wound dehiscence, hematoma, or infection, and both groups exhibited good approxima- tion of the skin edges. Sloughing of the poly- mer was observed to varying degrees depen- dent on the size of thevwound and anatomic site. Whereas the majority of small wounds ranged from 25 percent to complete sloughing of the polymer at the 5- to 7-day visit, larger wound sites had only minor sloughing along T the periphery of the applied polymer. Ninety—Day F ollow—up Of the 111 patients, 110 returned for their 90-day postoperative visit. Excellent-to—good cosmetic outcome was noted in all patients from both groups. There was no evidence of healing abnormalities in any of the test or con- trol patients. In the control group, a number of incisions had visible suture tracks, whereas wounds in the test group healed without pe- ripheral scarring or suture marks. There were similar outcomes between the octyl-2—cyanoac- rylate group and the suture group on the mod- ified Hollander wound evaluation scale. At the 90-day follow-up visit, mean wound evaluation scores were 0.235 for the suture group (con- trol) and 0.306 for the octyl-2-cyanoacrylate group (test). Statistically, there was no signifi- cant difference between wounds treated with octyl-2—cyanoacrylate or suture as evaluated us- ing the modified Hollander scale ([3 = 0.51). One-Year F ollow-up Evaluation Of the 111 patients enrolled in the study, 100 (90 percent) returned for their long-term, 1-year follow—up wound evaluation. No compli- cations were noted in either the octyl-2- cyanoacrylate or the suture group. However, 2215 persistent suture tracks remained evident in some of the control patients. At 1 year, the mean visual analog scale cosmetic outcome was 21.7 1“ 16.3 mm versus 29.2: 17.7 mm for the octyl-2—cyanoacrylate group and suture group, respectively. The lower score represented an improved cosmetic outcome for incisions treated with octyl-2-cyanoacrylate and was sta- tistically significant at p = 0.03 (Fig. 3, below, right) . DISCUSSION The concept of a surgical tissue adhesive for superficial skin closure is an attractive alterna- tive to the use of sutures to both physicians and patients. Suture placement always requires ap- plication of an anesthetic agent and takes sig- nificantly more time than application of octyl- 2-cyanoacrylate. Although placement (under anesthesia) and removal of sutures rarely causes pain, a high degree of patient anxiety associated with these procedures remains. This is particularly true within the pediatric popula- tion or when small-caliber sutures must be re- moved from sensitive areas of the face (nose, eyelid, lips, etc.). Many children will not permit the surgeon to remove sutures without being restrained or sedated. Use of octyl-2-cyanoacry- late for skin closure significantly decreases the time of treatment‘ for wound closure and elim- inates the need for postoperative suture re- moval. And, although 5- to 7-day follow—up vis- its may still be necessary, patients will not experience the anxiety and discomfort often associated with suture removal. Additional ben- efits of octyl-2-cyanoacrylate noted during the study include ease of use; formation of its own protective barrier, eliminating the need for ad- ditional bandages; and excellent cosmetic out- come. Analysis of the study data revealed that skin closure with octyl-2-cyanoacrylate provided equivalent cosmetic results when compared with sutures as determined by the modified Hollander wound evaluation scale performed at the 90-day time point. This scale has less ability to discern small differences in cosmetic outcome than the visual analog scale wound evaluation method. The visual analog scale scores obtained by analysis of the long-term, 1-year postoperative photographs revealed su- perior cosmetic results of incisions closed with octyl-2-cyanoacrylate compared with controls treated with sutures. The overall excellent cos- metic results and absence of complications (in- ,, ,,, ,_ m. 2216 fection, dehiscence, etc.) can be attributed, in part, to the fact that most of the incisions were clean, incised wounds with appropriate use of subcutaneous closure. One would expect less optimal results in traumatic wounds that are closed without the use of subcutaneous su- tures. Before adhesive application, wounds must be evaluated for placement of subcutaneous sutures to eliminate subcutaneous dead space, decrease wound tension, and maximize skin edge eversion (Fig. 5). Full-thickness wounds with a high level of underlying muscular activ- ity (perioral region, forehead, and over the mandible) or where deep tissues have been separated through incision or laceration should be treated with subcutaneous sutures before skin closure. If the deep tissue layers are not reapproximated, the dead space resulting from the lack of subcutaneous tissue approxi- mation may result in a depressed scar (Fig. 6). Thinner skin, such as that in the eyelid, con- tains minimal subcutaneous tissue; therefore, PLASTIC AND RECONSTRUCTIVE SURGERY, November 1998 subcutaneous sutures are not required before epidermal skin closure. The determination as to when subcutaneous sutures should be used will require physician discretion. In our expe- rience, subcutaneous sutures should be ap- plied (l) to all full-thickness wounds requiring obliteration of subcutaneous dead space, (2) to alleviate wound tension noted during skin clo- sure, and (3) to enhance skini edge eversion where necessary (thicker, less pliable skin, e.g., forehead, cheek). Even with proper prepara- tion and subcutaneous suture placement, con- ventional suturing methods (vertical mattress sutures) remain the treatment of choice in areas where marked wound edge eversion is desired? Some surgeons may believe that the applica- tion of subcutaneous sutures provides ade- quate skin edge eversion and requires only adhesive strips for epidermal closure. In our experience, application of adhesive strips will tend to decrease the degree of skin edge ever- sion because of the vertical component of FIG. 5. (Above, left) Everted skin closure after excision of benign tumor from forehead. (Above, right) Polymerization of octyl-2-cyanoacrylate leaves a thin layer of polymer on wound. (Below, left) Polymer begins to peel off 7 days after application. (Below, right) One—year postoperative photograph of healed surgical site with acceptable cosmetic outcome. Arrows point to the ends of the scar. V0. 2216 fection, dehiscence, etc.) can be attributed, in part, to the fact that most of the incisions were clean, incised wounds with appropriate use of subcutaneous closure. One would expect less optimal results in traumatic wounds that are closed without the use of subcutaneous su- tures. Before adhesive application, wounds must be evaluated for placement of subcutaneous sutures to eliminate subcutaneous dead space, decrease wound tension, and maximize skin edge eversion (Fig. 5). Full-thickness wounds with a high level of underlying muscular activ- ity (perioral region, forehead, and over the mandible) or where deep tissues have been separated through incision or laceration should be treated with subcutaneous sutures before skin closure. If the deep tissue layers are not reapproximated, the dead space resulting from the lack of subcutaneous tissue approxi- mation may result in a depressed scar (Fig. 6). Thinner skin, such as that in the eyelid, con- tains minimal subcutaneous tissue; therefore, FIG. 5. (Above, left) Everted skin closure after excision of benign tumor from forehead. (Above, right) Polymerization of PL.»'\STI('I AND RE(j()NSTRUCT1\/I-L SURGERY, November 1998 subcutaneous sutures are not required before epidermal skin closure. The determination as to when subcutaneous sutures should be used will require physician discretion. In our expe- rience, subcutaneous sutures should be ap- plied (l) to all full-thickness wounds requiring obliteration of subcutaneous dead space, (2) to alleviate wound tension noted during skin clo- sure, and (3) to enhance skin edge eversion where necessary (thicker, less pliable skin, e.g., forehead, cheek). Even with proper prepara- tion and subcutaneous suture placement, con- ventional suturing methods (vertical mattress sutures) remain the treatment of choice in areas where marked wound edge eversion is desired? Some surgeons may believe that the applica- tion of subcutaneous sutures provides ade- quate skin edge eversion and requires only adhesive strips for epidermal closure. In our experience, application of adhesive strips will tend to decrease the degree of skin edge ever- sion because of the vertical component of g/ octyl—2-cyanoaciylate leaves a thin layer of polymer on wound. (Below, Icy?) Polymer begins to peel off 7 days after application. (Below, right) One-year postoperative photograph of healed surgical site with acceptable cosmetic outcome. Arrows point to the ends of the scar. Vol foi H( orf en he ad po wk Vol. 102, No. 6 / ocrn.-2-cYANoAc.R\iATE FOR SKIN CLOSURE 2217 FIG. 6. (Lefl) Closure of wound with octyl—2—cyanoac1“ylate without elimination of subcutane- ous dead space. (Right) Healing and scar contracture results in an inverted scar as overlying skin retracts into area of dead space. FIG. 7. (Above, left) Unfavorable bevel of skin edges of wound that would make proper approximation of epidermis difficult. (Above, right) Application of octyl-2—cyanoacrylate on in- cision with unfavorable bevel. Note how polymer could enter wound between epidermal skin edges. (Below) Use of vertical mattress sutures to close incision and evert skin edges in wound with unfavorable bevel. force applied by the tape to the skin edge. However, octyl-2—cyanoacrylate has excellent mechanical strength and can be used to set the orientation of the skin edge and hold, or even enhance, skin edge eversion while the wound is healing and scar contracture occurs. Another advantage of octyl-2-cyanoacrylate is that the polymer provides a waterproof clear dressing, whereas adhesive strips will fall off when wet. Despite the superiority of octyl-2-cyanoacrylate over adhesive strips, neither is as effective as vertical mattress sutures in enhancing skin edge eversion. Therefore, sutures should be used in cases where maximal skin edge ever- sion is necessary because of nonpliable thick skin or where unfavorable bevel of the skin edges exists (Fig. 7). A wound with an unfavor- able bevel can be converted to a more favor- Vol. 102, No. 6 / OCTYL-2-CYANOACRYLATE FOR SKIN CLOSURE 4 2217 FIG. 6. (Left) Closure of wound with octyl-2-cyanoacrylate without elimination of subcutane- ous dead space. (Right) Healing and scar contracture results in an inverted scar as overlying skin retracts into area of dead space. FIG. 7. (Above, left) Unfavorable bevel of skin edges of wound that would make proper approximation of epidermis difficult. (Above, right) Application of octyl-2-cyanoacrylate on in- cision with unfavorable bevel. Note how polymer could enter wound between epidermal skin edges. (Below) Use of vertical mattress sutures to close incision and evert skin edges in wound with unfavorable bevel. force applied by the tape to the skin edge. However, octyl-2—cyanoacrylate has excellent mechanical strength and can be used to set the orientation of the skin edge and hold, or even enhance, skin edge eversion while the wound is healing and scar contracture occurs. Another advantage of octyl-2-cyanoacrylate is that the polymer provides a waterproof clear dressing, whereas adhesive strips will fall off when wet. Despite the superiority of octyl-2—cyanoacrylate over adhesive strips, neither is as effective as vertical mattress sutures in enhancing skin edge eversion. Therefore, sutures should be used in cases where maximal skin edge ever- sion is necessary because of nonpliable thick skin or where unfavorable bevel of the skin edges exists (Fig. 7). A wound with an unfavor- able bevel can be converted to a more favor- 2218 able wound by modifying or reexcising the skin edge. However, additional skin excision may not be possible or advisable. Use of octyl-2-cyanoacrylate has also been shown to significantly decrease the time re- quired to close a traumatic or surgical wound.15’“5 Although many wounds 'may still need subcutaneous suture; application, the ap- plication of octyl-2-cyanoacrylate requires sig- nificantly less time than applying multiple skin sutures. The larger the wound, the greater the time savings, as the application time of octyl-2- cyanoacrylate, unlike that of sutures, does not increase significantly with incision size. The reduced time for skin closure resulted in shorter treatment time and, therefore, less pa- tient anxiety and decreased cost. Additionally, patient reaction to the application of the adhe- sive for skin closure was extremely favorable, and patients preferred the use of and the final cosmetic result from the adhesive. Few, if any, patients required reassurance as to the efficacy or safety of octyl-2-cyanoacrylate for wound clo- sure. I Surgeons must avoid depositing polymer be- low the level of the skin into the wound. Use of tissue forceps to aid in skin edge approxima- tion and eversion while applying the polymer should be practiced before patient applica- tions. The best way to avoid subcutaneous dep- osition of the adhesive is to make sure that the skin edges are precisely approximated with for- ceps and/ or everting subcutaneous sutures be- fore application of octyl-2-cyanoacrylate. If the material is accidentally deposited below the level of the epidermis, the polymer will even- tually extrude through the incision site, similar to an extruding subcutaneous suture or other foreign body. In this study, careful use of the adhesive resulted in the absence of complica- tions and excellent long-term wound cosmesis. Wounds that are likely to drain postopera- tively should not be completely closed with the polymer because it may inhibit proper wound drainage. Alternatively, a small region should remain uncovered or closed with a single su- ture to allow for drainage. Octyl-2—cyanoacry- late should not be used in patients that dem- onstrate any degree of infection, are at risk for delayed wound healing (diabetics or patients with collagen vascular diseases), or who have a history of contact dermatitis. If a seroma or wound infection should develop, the polymer can be removed from a small area of the inci- PLASTIC AND RECONSTRUCTIVE SURGERY, November 1998 sion to allow drainage without wound dehis- cence. Octyl-2—cyanoacrylate has several advantages over previous cyanoacrylate derivatives used as surgical tissue adhesives. This longer chain cy- anoacrylate derivative is potentially less tissue toxic, has an increased three-dimensional breaking strength,” and is easier to use. Octyl- 2—cyanoacrylate has a plasticizer, which in- creases the pliability of the polymer, thus, re- ducing the cracking and early peeling seen with shorter-chain cyanoacrylate derivatives. The pliable nature of this product makes it ideal for use over flexible skin surfaces, such as the face and neck; Finally, unlike other cyano- acrylate deratives, octyl-2-cyanoacrylate is strictly for external use as a skin closure device. Proper patient selection,‘ meticulous tech- nique, and limitation to external use will elim- inate many of the previous problems, noted when cyanoacrylate derivatives were used in surgery. Dean M. Toriumi, M.D. Division of Facial Plastic and Reconstructive Surgery, Department of Otolaryngology—-Head and Neck Surgery (M/C 648) Room 2.42 University of Illinois at Chicago 1855 W. Taylor St; Chicago, Ill. 60612 ACKNOWLEDGMENTS We wish to thank Kathy Reidy for her assistance in the ‘ execution of the study and Edward L. Applebaum, M.D., for his help in preparing the manuscript. This study was partially funded by Closure Medical Cor- poration, Raleigh, Nv.C. REFERENCES 1. Borges, A. F. Elective Incision: and Scar Revision. Boston: Little, Brown, 1973. 2. 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