Reconstruction of oncologic nasal defects using the forehead flap: technical aspects and results

Introduction Skin cancer frequently hits the nasal pyramid. Reconstruction of the nasal defects of the nasal pyramid after oncologic resection is challenging for plastic surgeons due to the anatomic complexity of the nose. The forehead flap is a pedicled flap used since antiquity in the reconstruction of nasal defects. Methods We retrospectively reviewed the medical records of 30 patients operated for skin cancer of the nasal pyramid with reconstruction of the skin defect by forehead flap between the years 2008 and 2020. Results The mean age was 66.3. The sex ratio was 2.75. The tumor mean size of the tumor was 34 mm ranging between 19 and 50 mm. Twenty-nine patients required a second time surgery for flap severing and degreasing. The paramedian forehead flap was used in 20 cases, the “sea gull” flap in 5 cases, the inclined FF in 4 cases, and the island FF in 1 case. Conclusion Surgical techniques of FF offer good aesthetic results with a lesser morbidity rate. Our retrospective report attests to the reliability of FF as the workhorse for the reconstruction of small and average nasal defects.


Background
The central and prominent position of the nose makes it the most sun-exposed area of the face.Therefore, skin cancers frequently hit the nasal subunits.Reconstruction of the defects following tumor resection is always challenging for the head and neck surgeon as the nasal pyramid is considered one of the most difficult areas in plastic surgery.The forehead flap (FF) is an old flap used since antiquity in the reparation of nasal defects [1].The rich blood supply of the forehead by the supratrochlear, the supraorbital and the superficial temporal arteries, and the skin color and texture match with the nose are the main advantages of the forehead flap [2].Besides, its great versatility and accessibility are seductive not only for plastic surgeons but for every cancer surgeon.As a result, the FF is the workhorse for oncologic nasal defect reconstruction.We present in this report our experience with the FF in the oncologic nasal defect reconstruction.We focused on the surgical technique followed and the postoperative results.

Study and population
This is a retrospective descriptive study.Between the years 2008 and 2020, medical records of patients operated for skin cancer of the nasal pyramid and who beneficiated of reconstruction of the nasal defect by the FF were retrieved.Tumors were previously diagnosed by *Correspondence: Rihab Lahmar rihab.lahmar.med@gmail.com 1 Head and Neck Surgery Department, Salah Azaiez Oncology Institute, Tunis, Tunisia biopsy under local anesthesia.Only basal cell and squamous cell cancers were included.Patients who underwent radiation therapy as first-line treatment were excluded from the study.Therapeutic decisions were made within a multidisciplinary committee after ruling out distant metastases.

Preoperative assessments
All patients were clinically evaluated before surgery.Associated comorbidities were searched and noted.The forehead skin laxity was tested, and tumors size and extensions were evaluated.A pre-anesthetic evaluation was performed in all patients.

Surgical technique
All operations were performed under general anesthesia.A two-staged procedure was performed in the majority of cases.The tumor was first resected respecting the safety margins of healthy tissue between 5 and 10 mm in basal cell carcinoma and superior to 10 mm in squamous cell carcinoma.The cutaneous defect was measured and traced on the forehead.The forehead skin was then deeply incised to the frontal periosteum following the landmark previously delineated.The flap was designed with a lateral curve when the anterior hairline level was low.The flap was carefully taken down to the eyebrow level where it should be rotated and shaped to match the nasal defect.The flap arc of rotation was tested using strip gauze.Special attention was given when reaching the orbital rim to not harm the supraorbital artery.Coverage of the defect was performed, and the skin was sutured using a 3-0 Vicryl.The donor site was sutured using 2-0 to 3-0 Vicryl and then covered using "tullegras" dressings.Antibiotherapy was administrated during the postoperative period.The flap was revisited 3 weeks later for severing and degreasing.A single-staged procedure was exceptionally used.After tumor resection, the forehead flap is delivered through a subcutaneous tunnel to the skin defect avoiding the flap severing time.
The surgical steps of the two-staged procedure are illustrated in Fig. 1a, b, c, d, and e.

Follow-up and evaluation of the surgical scar
Patients were closely followed every 2 months during the first year.A careful medical examination was performed to check for local relapses.Esthetic results were subjectively evaluated based on patient satisfaction.

Statistical analysis
Descriptive statistics were performed using SPSS 26 for windows.Means and frequencies were calculated with minimal and maximal values which were also calculated.

Results
Thirty patients met the inclusion criteria.The mean age in the study was 66.3 ranging between 29 and 80 years.There was a notable male predominance with a sex ratio equal to 2.75.Associated comorbidities were diabetes mellitus in five patients and hypertension in three patients.Twelve patients (40%) were cigarette smokers.Nine patients had light skin.Sun exposure was documented in 22 cases.The most concerned professions were agriculture (six cases) and construction worker (four cases).Patients consulted in a mean delay of 10 months after the appearance of the nasal lesion ranging between 1 month and 3 years.
The initial tumor histology was equally divided between squamous cell carcinoma (50%) and basal cell carcinoma (50%).The mean size of the tumor was 34 mm ranging between 19 and 50 mm.It was limited to one nasal subunit in nine cases.In the remaining 21 cases, it was extended to 2 subunits in 8 cases, 3 subunits in 10 cases, and more than 3 in 3 cases.
Different types of FF were used.The paramedian forehead flap was used in 20 cases, the "sea gull" flap in 5 cases and the inclined FF in 4 cases.The remaining patient had an island FF; it was an 80-year-old woman operated for basal cell cancer (Fig. 2a, b, c).The postoperative period was uneventful for the majority of patients.Only 5 patients (16.66%) presented postoperative complications: 4 cases of wound infection which responded well to antibiotherapy and 1 case of wound gap that required reoperation.The mean hospital stay was 5.8 days ranging between 5 and 8 days.Only one patient underwent a single-staged operation.It was an island flap variation performed in 80-year-old woman who presented a basal cell carcinoma.The remaining 29 patients required secondtime surgery for flap severing and degreasing.It was performed in a mean time of 21 days after the first operation.Aesthetic results were judged satisfactory in 16 patients.No local recurrences were recorded during the follow-up.

Discussion
The forehead flap has been known since antiquity.In 600 BC, an Indian surgeon named Sushruta was the first to perform nasal reconstruction using a mid-FF which was since that time called the Indian flap [1].Later in history, evidence of the usage of FF was found in Italy during the Renaissance [3].Millard and Menick developed the paramedian position of the FF excluding the glabellar skin which reduced drastically morbidity and improved the flap versatility [4].
Nowadays, the FF is the workhorse of nasal defect reconstruction.In this study, the indication of FF was the reconstruction of nasal defects after oncologic resections in all patients.Basal and squamous cell carcinoma were the two histological types of skin malignancies in this report.More rare histological types as melanoma, adenoid cyst carcinoma, and sarcoma were reported [5].Incidence of this disease is difficult to precise as it has often been classified as skin cancer rather than cancer of the nasal pyramid [6].
Post-traumatic defects and deformities of the nasal pyramid are the other main indications of the FF.Beyond  the nose, the FF was particularly used in the reconstruction of the exenterated orbit, the medial canthus, and the radix [7,8].
Candidates to undergo this surgery should be well selected and examined.Smoking cessation can improve post-operative outcomes [9].Thinning of the distal flap during flap transfer should be limited in smokers and patients with associated comorbidities [9,10].In our series, this category of patients had no particular issues.Namdev prefers using the midline FF in average-sized defects [11]; he believes that midline FF receives richer blood supplies from both trochlear, supraorbital, and temporal vessels from both sides which could be an interesting alternative for patients with high risk.A Doppler imaging in case of doubt should be performed especially in patients with a previous history of radiation therapy or transverse scars overlaying the supratrochlear artery [9].
Perhaps one of the main drawbacks of skin defect reconstruction using FF is the multi-staged operation.We followed the traditional two-stage operation: the first stage consists of flap transfer with thinning and contouring and the second stage of flap section and inset.Some authors popularized the three-staged operation which consists in dividing the first stage into two separate steps: a full-thickness flap transfer followed by flap re-elevation thinning and contouring [12,13].Although this operative technique offers better esthetic results for large defects according to these surgeons, it remains a very exhausting and time-consuming procedure for the patient.Other authors described a single-stage operation for patients with associated comorbidities and possibly smokers [14].For this single-stage operation, the flap is thinned, and a glabellar subcutaneous tunnel is created to transfer the FF to the nose [14,15].We think this attitude is complicated and could compromise the pedicle.Our two-stage operation was well tolerated by patients and offered acceptable esthetic results.
FF is a robust flap; patients are usually left with minimum postoperative care.Only 3 of our patients presented postoperative complications which had all favorable issues.Sanchez et al. studied the postoperative outcomes in 41 patients who benefited from reconstruction of the nasal defect with paramedian FF after oncologic resections [16].The rates of early and late complications were respectively 14.6% and 31.7%[16].In a more recent and larger similar cohort, postoperative infection was the most reported complication (2.9%) followed by bleeding 1.4% [17].According to the same study, 4% of patients returned to the emergency department within 30 days of surgery, and 2.5% were readmitted within the same period [17].In a multivariate analysis, postoperative bleeding, associated medical history of hypertension, adjacent tissue transfer, and ear cartilage graft were significant predictive factors for readmission according to these authors [17].Stahl et al. compared the postoperative results of nasal reconstruction with paramedian FF in 2 stages (87 patients) and 3 stages (100 patients) [18].The partial necrosis rate was not significant when comparing the two groups (3.4% in 2 stages vs. 5% in 3 stages, p = 0.6) [18].
Esthetic results were judged satisfactory in 16 among 30 patients in our series.We believe these results depend on the extent of the surgical resection.One of the frequently reported esthetic issues relative to the FF is the transposition of the frontal hairy skin into the nasal pyramid.Laser or chemical depilation could be performed before surgery for patients with hairy frontal skin [19].

Conclusion
For many patients, FF is an excellent choice in the reconstruction of nasal defects after oncologic resections.Surgical techniques of FF have benefited from many improvements over time which drastically reduced postoperative complications and led to better aesthetic results.This retrospective report attests to the reliability of FF as the workhorse for the reconstruction of small and average nasal defects.It offers good aesthetic results with a lesser morbidity rate.Besides, it is worth noting that FF is technically easy to learn and perform.Probably the main drawbacks remain the anesthetic frontal scar and the multi-staged operative procedure

Fig. 1 a
Fig. 1 a Initial budding ulcer lesion.b Significant loss of substance after tumor excision.c Coverage of the loss of substance with an inclined forehead flap.d Result 3 weeks after surgery before weaning the flap

Fig. 2
Fig. 2 Island frontal flap.a Significant loss of substance after excision of a tumor of the nasal pyramid.b and c Repair by island frontal flap