Mohs ’98: Single-procedure Mohs surgery with immediate reconstruction

Mohs ’98: Single-procedure Mohs surgery with immediate reconstruction PAUL E. BERNSTEIN, MD, FACS, San Diego, California

For more than 50 years, the Mohs technique has offered both the highest cure rate for skin cancers and the maximum preservation of surrounding normal tissue. Mohs skin cancer excision is traditionally performed by a Mohs dermatologist, followed by a secondary repair by a head and neck or plastic surgeon. This study comprises a review of 300 cases involving single-procedure Mohs therapy with immediate one-anesthetic reconstruction. The data reviewed include types of reconstructions, cosmetic results, complications, and recurrence rates. In addition to offering the psychologic and quality advantages of immediate closure, the procedure allows patients to return to work sooner. With changes in technique ranging from the chemosurgery of the 1930s to the fresh-tissue methods of the 1970s, single-procedure Mohs is the logical next step in the evolution of Mohs surgery. (Otolaryngol Head Neck Surg 1999;120:184-9.)

Since the 1930s the Mohs technique has evolved from chemosurgery involving a zinc chloride paste to the fresh-tissue frozen-section technique. Mohs surgery offers both high cure rates for skin cancers and maximum preservation of surrounding normal tissue, thus optimizing cosmetic repair. Although there have been reports of immediate reconstruction following Mohs skin cancer excision,1 it has traditionally been done as two separate procedures: the excision of the lesion by a Mohs dermatologist, followed by reconstructive repair undertaken by a head and neck or plastic surgeon. The delay between the two procedures averages hours to days and requires the administration of two separate anesthetics. This report details experience with 300 cases in which Mohs excision and reconstruction were carried out in a single procedure by the same surgeon. In the United States, an estimated 700,000 new cases From the Department of Head and Neck Surgery, Southern California Permanente Medical Group. Reprint requests: Paul E. Bernstein, MD, FACS, Department of Head and Neck Surgery, Kaiser Permanente, 4647 Zion Ave, San Diego, CA 92120. Copyright © 1999 by the American Academy of Otolaryngology– Head and Neck Surgery Foundation, Inc. 0154-5998/99/$8.00 + 0 23/1/88801 184

of squamous cell and basal cell carcinoma appear each year, making these malignancies by far the most common form of human cancer.2 The majority, almost 80%, are basal cell carcinomas; the remaining 20% are squamous cell carcinomas. Most of these neoplasms occur in the sun-exposed skin of the head and neck, and epidemiologic studies have implicated UV radiation exposure as one risk factor. New studies have shown a genetic predisposition as well, possibly an inactivation of a gene on chromosome 9 that may be necessary for basal cell carcinogenesis.3 Most basal cell carcinomas can be treated with the standard techniques of excision, electrodessication, and curettage; cryosurgery; or radiotherapy. The cure rates for these procedures in primary lesions are all approximately 90%. Mohs surgery has a cure rate approaching 99% in primary and 95% on recurrent basal cell carcinomas. Guidelines developed by the American Academy of Dermatology4 are summarized in Table 1. The number of cases referred for Mohs surgery has increased over the last 5 years, concomitant with the familiarity and availability of Mohs surgery. This report describes a single-procedure Mohs excision and reconstruction technique, including patient population, location of skin cancers, costs involved, and types of reconstructive procedures. Because the Mohs technique is increasingly popular, head and neck surgeons should be aware of the reconstructive challenges following Mohs skin cancer excision. METHODS AND MATERIAL The Mohs procedures with immediate reconstruction were all done by the author at the Department of Head and Neck Surgery, Kaiser Permanente Medical Center, San Diego, Calif, between June 1, 1994, and Dec 31, 1996. All patients were entered into a Paradox database for prospective and retrospective analysis, and photographs of all defects and reconstructions were taken. One-year postoperative photographs were also taken of most patients. Three hundred procedures were analyzed during this period; most were performed in patients between the ages of 50 and 80 (Table 2). Fifty-eight percent of the patients were female, 42% male. Frederick Mohs described his initial chemosurgery technique in 1941.5 In the 1970s the technique was adapted by Tromovitch and Stegman for use with fresh frozen tissue.5 The single-procedure technique involves a careful collabo-

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ration among the surgeon, pathologist, Mohs technician, and patient. Because several sequential layers of excision and microscopic evaluation may be necessary, the procedures are scheduled after normal office hours, when the pathologist and technician can rapidly process multiple frozen sections. Three patients (or three separate skin cancers) are usually scheduled for a 3 hour Mohs session. The patients are given local anesthetics, usually 2% xylocaine with epinephrine or 0.5% bupivacaine hydrochloride with epinephrine, in an ambulatory-surgery setting or minor-procedure office operating room. The skin cancer is cleaned with povidone-iodine surgical scrub soap, and a grounding pad is placed on the patient’s arm for the electrosurgical unit used to cauterize bleeding vessels. The scalpel is held at a 45-degree angle to elevate a rim of normal tissue with removal of the skin cancer. All tumors are clearly oriented with a suture or marking pen at the time of the excision. The surgeon must personally deliver the specimen to the pathologist so that it may be properly oriented. The pathologist makes a diagram of the specimen and marks the edges with color coding in at least two dimensions. The specimen is flattened to bring both lateral and deep surgical margins into the same plane and cut to sizes appropriate for frozen-section processing. The specimen is then cut horizontally from the undersurface toward the margin, yielding horizontal instead of vertical sections. The entire deep and peripheral margin is evaluated, and the surgeon examines the microscopic sections with the pathologist to determine whether tumor is present at any margin. If necessary, the surgeon excises additional levels in areas mapped as positive. After complete skin cancer excision, with the patient still under the local anesthetic, the resulting area of tissue loss is closed immediately with an appropriate facial plastic surgery technique. The wounds are bandaged, and patients with drains are seen the next day; others are seen in 7 days for suture removal. Detailed wound-care instructions are discussed with the patient and given to him or her in written form to take home. RESULTS

The Paradox database of 300 Mohs cases, including some patients with more than one skin cancer, was reviewed. One patient with xeroderma pigmentosa had 11 separate lesions excised during this period. By far the major skin cancer type was basal cell carcinoma (90%); squamous cell carcinoma (6%) was the second most common. Most repairs involved the nose, with the ala being the most common location overall (Table 3). Five major types of repairs were done, depending on the location and size of the defect (Table 3). Transposition flaps and nasolabial flaps were commonly used to repair nasal defects; simple, horizontal, or circular advancement flaps were used on the forehead, cheek, eyebrows, and glabella; transposition and glabellar

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Table 1. Indications for Mohs surgery High-recurrence areas

Nasal grooves and septum, melonasal and mesolabial folds, helix of auricles, temples, scalp, preauricular and postauricular regions Nasal ala and tip, upper lip, eyelids, canthi

Maximum tissue preservation required Basal cell carcinomas Morphea-type, infiltrating, metatypical with aggressive histologic features Squamous cell carcinomas Adenoid, spindle, undifferentiated with aggressive histologic features Larger tumors >2 cm Ill-defined and indistinct borders Recurrent tumors

Table 2. Age distribution Age (yr)

<30 30–40 40–50 50–60 60–70 70–80 >80 TOTAL

No. (%)

11 (3.7) 13 (4.3) 43 (14.3) 65 (21.6) 61 (20.4) 81 (27.0) 26 (8.7) 300 (100.0)

flaps were used for canthal defects; and skin grafts were used most frequently for ear defects. Antibiotics were used in most cases involving flaps and grafts. Cephalexin was the antibiotic most commonly prescribed. No major complications occurred. Minor complications included partial flap or graft loss and minor wound dehiscence (Table 4). In no case did dehiscence necessitate repeat surgery, and complete flap or graft loss did not occur. There were no wound infections in this series. In two cases, recurrence of cancer was detected, for a rate of less than 1%. A cost-per-case analysis was conducted by the Kaiser Permanente Management Engineering Department (Table 5). All costs except materials (nonpayroll costs) were calculated. The total cost per case in 1994 dollars was determined to be $270 for single-procedure Mohs, compared with $632 for classic excision with secondary closure (Table 6). Having the pathologist read the frozen sections yielded significant cost savings in that the surgeon was able to operate on more than one patient during a single Mohs session. During the same period (180 minutes),

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Table 3. Flap reconstruction and locations Location

Forehead/ glabellar flap

Nasal ala Dorsum Nasal tip Cheek Lips Temple Ear Forehead Paranasal Canthus Eyebrow Scalp Neck Glabella Chin TOTAL

45-Degree transposed flap

Nasolabial flap

35 15 20 4 5 11 1

7

5

11 1

1

12

97

12

Complication

No.

Partial flap loss Partial graft loss Small dehiscence

4 2 2

Total

53 43 33 27 24 22 22 17 15 13 7 7 6 6 5 300

14

14

Table 6. Cost per patient: Mohs surgery followed by secondary closure Parameters

Table 5. Cost per patient: single procedure

Staff resources required Head and neck surgeon Nurse assistant Pathologist Pathology technicians Total cost Mean no. of patients Cost per patient

Skin grafts

7 20 13 23 19 11 7 17 15 3 7 6 6 6 5 165

5

Table 4. Minor complications

Parameters

Advancement and complex

No.

Min

Cost/ min

Cost/ procedure

1 1 1 2

180 180 180 120

$1.75 $ .35 $1.66 $ .56

$315 $ 63 $299 $134 $811

3 $270

the Mohs dermatologist was busy processing and reading the slides from a single patient. DISCUSSION

Mohs surgery is an increasingly appealing option for patients with large (>2 cm), recurrent, or difficult-totreat basal cell and squamous cell carcinomas, who require precise and effective surgical treatment, as defined in Table 1. Immediate closure of defects enhances patient satisfaction and reduces the need for more than one procedure or multiple postoperative visits. All the patients seen in this series were referred to

Staff resources required Dermatologist Nurse Histology technician Head and neck surgeon Nurse Total cost of excision Total closure Total procedure

No.

Min

Cost/ min

Cost/ procedure

1 1 1 1 1

180 180 180 60 60

$1.85 $0.35 $0.38 $1.75 $0.35

$333 $ 63 $ 68 $105 $ 63 $464 $168 $632

the Head and Neck Surgery Department by the dermatologists at the study institution after meeting the guidelines for Mohs surgery (Table 1) or expressing a strong preference for this treatment. All defects, including large ones, were repaired in the single-procedure setting. Most of the repairs involved standard facial plastic surgery techniques, and local flaps were most often used (Table 3). The most commonly affected area, the nasal ala, was repaired with both 45-degree transposition flaps and nasolabial flaps. Transposition flaps (Fig. 1) tended to minimize the need for secondary surgery necessitated by the use of nasolabial flaps to redefine the alar crease (Fig. 2). Transposition flaps were also extremely helpful in closing large defects of the temple (Fig. 3) and upper lip (Fig. 4). Glabellar flaps were found to be cosmetically pleasing in the area of the medial canthus (Fig. 5). No ectro-

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Fig. 1. Nasal transposition flap.

Fig. 2. Nasolabial flap.

pions were noted with the use of this technique. A similar flap, involving a larger V-to-Y advancement, was found to be advantageous for larger nasal dorsal defects. Sliding horizontal advancement flaps were used in the area of the upper eyebrow to prevent contracture in this area. Skin grafts were used commonly in reconstructing the ear, although some authors have published findings supporting secondary-intention healing in this area.6 Complex advancement flaps were commonly used in the area of the lower and upper lips. Healing by second intention has also been reported as

an option on concave areas of the face, such as the alar crease or medial canthus; however the cosmetic results are usually only satisfactory.7 In convex areas or larger lesions, healing by secondary intention is usually only recommended in poor surgical candidates or patients who do not want to undergo a second procedure.7 Triamcinolone (Kenalog; 40 mg/ml) was injected with the use of a Dermo-Jet needleless high-pressure injector (model G; Robbins Instruments, Inc., Chatham, NJ) on most flaps. This treatment proved extremely valuable in speeding up scar maturation and reducing the fullness of both transposition and nasolabial flaps.

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Fig. 3. Temple transposition flap.

Fig. 4. Upper-lip transposition flap.

Injections were started 1 month after surgery and repeated every 6 weeks for the first five months. Keeping the injection within the flap area, avoided subcutaneous atrophy or pigment changes. The treatment has been found elsewhere to speed up scar maturation from 6 to 3 months.1 Wound-infection rates for Mohs procedures closed on the same day but not in a single procedure have been reported as 2.29%, falling within the range predicted for clean surgical procedures.4 When wound closure is delayed past the first day, infection rates are still less than 5%; thus no statistically significant difference in infection rates exists between primary- and secondaryclosure procedures.9 However, infection rates as high as 28% have been reported in cases in which ear cartilage was involved and allowed to close by secondary scar contraction,4 a rate that is statistically significant (p < 0.05) compared with that of this series of single-procedure Mohs surgeries. Another study of delayed reconstruction after Mohs chemosurgery revealed a woundcomplication rate of 6%. 10 In patients with delayed reconstruction, pseudoepithelial hyperplasia has been mistaken for recurrent squamous cell carcinoma, leading to unnecessary removal of tissue.11

Recurrence rates were less than the 1% predicted. On retrospective review, technical causes were found to be the most likely cause of recurrence.12 The most common reasons were incomplete visualization of the epidermis and mapping errors. Patient characteristics, such as xeroderma pigmentosa, radiodermatitis, immunosuppression, and basal cell nevus syndrome also enhance recurrence rates. Photographs are important in the determination of whether a lesion is a true recurrence or an adjacent new skin cancer that may have been transposed with a flap-type reconstruction. CONCLUSION

Immediate, single-procedure Mohs surgery carries many advantages: This procedure, used in areas of the eyelids, prevents ectropion and corneal exposure, and, when used on the lips, it prevents drooling and oral incontinence. Patient satisfaction is enhanced because the patient does not have to care for a large, unsightly wound before closure. Photographs are extremely helpful in demonstrating to the patient the size of the defect and the type of closure performed. In addition, the patient is able to return to work sooner than in delayed procedures.

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Fig. 5. Glabellar flap.

Single procedure Mohs is a more cost-effective way of performing Mohs cancer surgery. The head and neck surgeon, working closely with a pathologist, can quickly master the frozen-section technique. Although more costly than standard methods of treatment, in properly selected patients, it minimizes long-term costs because the chance of recurrence is lessened. The reported disadvantage of single-procedure Mohs is that patients appreciate and respect the expertise provided by both the Mohs dermatologist and the reconstructive surgeon.5 According to them, it prevents the reconstructive surgeon from compromising the surgical margins and unduly trying to avoid certain structures by thinking of the reconstruction at the same time. In this series of 300 procedures, this argument is without basis; the pathologist acted as the impartial judge of whether or not the cancer margin was clear. The added expertise of the head and neck surgeon in skin cancer excision helps minimize unnecessary risks to both motor and sensory nerves. Single-procedure Mohs combines a uniquely effective excisional technique for removing skin cancers with immediate single-anesthetic reconstruction. On the continuum ranging from the chemosurgery of the 1930s to the fresh-tissue methods of the 1970s, the Mohs ’98 technique is the logical next step in the evolution of Mohs surgery.

REFERENCES 1. Rudolph R, Miller SH. Reconstruction after Mohs cancer excision. Clin Plast Surg 1993;20:157-62. 2. Fleming ID, Amonette R, Monaghan T, et al. Principles of management of basal and squamous cell carcinoma of the skin. Cancer Suppl 1995;75:699-704. 3. Gailani M, Leffell D, Ziegler A, et al. Relationship between sunlight exposure and a key genetic alteration in basal cell carcinoma. J Natl Cancer Inst 1996;88:349-54. 4. Futoryan T, Grande D. Postoperative wound infection rates in dermatologic surgery. Dermatol Surg 1995;21:509-14. 5. Sahl W, Yessenow R, Brou J, et al. Mohs’ micrographic surgery and prompt reconstruction for basal cell carcinoma: report of 62 cases using the combined method. J Okla State Med Assoc 1994;87:10-5. 6. Levin BC, Adams LA, Becker GD. Healing by secondary intention of auricular defects after Mohs surgery. Arch Otol 1996; 122:59-67. 7. Deutsch BD, Becker FF. Secondary healing of Mohs defects of the forehead, temple, and lower eyelid. Arch Otol 1997; 123:529-34. 8. Stone JL. Mohs micrographic surgery: a synopsis. Hawaii Med J 1993;52:134-9. 9. Ratner D, Grande D. Mohs’ micrographic surgery: an overview. Dermatol Nurs 1994;6:269-73. 10. Mordick TG, Hamilton R, Dzubow LM. Delayed reconstruction following Mohs’ chemosurgery for skin cancers of the head and neck. Am J Surg 1990;160:447-9. 11. Calhoun KH, Wagner RF Jr, Kumar D, et al. Pseudoepitheliomatous hyperplasia mistaken for cancer after delayed reconstruction. South Med J 1995;88:454-7. 12. Hruza G. Mohs micrographic surgery local recurrences. J Dermatol Surg Oncol 1994;20:573-7.