The Occipital Flap for Reconstruction After Lateral Temporal Bone Resection

Objective  To investigate the use of the occipital rotational flap as an alternative reconstructive technique following lateral temporal bone resection.

Methods  A retrospective medical record review of 10 patients who underwent reconstruction with an occipital rotational flap after auriculectomy or lateral temporal bone resection. Patient and operative variables included age, preoperative ASA (American Society of Anesthesiologists) classification, operative time, total length of hospital stay, and use of preoperative and postoperative radiotherapy. Patient demographic characteristics and medical comorbidities were also recorded. Clinical outcomes included medical complications, minor and major wound complications, and donor site complications.

Results  Patients' mean age was 73.9 years, and mean ASA classification was 2.8. The mean operative time was 8.1 hours, and the mean length of hospital stay was 5.3 days. Three patients received preoperative radiotherapy, and 7 received postoperative radiotherapy. Two patients developed postoperative medical complications, 2 developed minor wound breakdown, and 1 developed a donor site complication.

Conclusion  The occipital flap method is reliable and should be considered as an option for reconstruction after lateral temporal bone resection in select patients.

Removal of invasive tumors involving the auricle and lateral skull base can be a challenge. Wide resection of these cancers often involves extension into the middle ear and mastoid space, and the parotid gland and upper cervical lymph nodes are frequently removed in an attempt to maximize locoregional control. The resulting defect can be significant, in size as well as complexity.

The primary goal of the reconstructive effort is to provide robust, well-vascularized soft tissue coverage to the area to avoid wound breakdown and to allow for subsequent radiotherapy. However, secondary goals, such as achieving favorable cosmetic outcomes and minimizing donor site morbidity from flap harvest, must also be considered.

Traditionally, pedicled myocutaneous flaps, such as the pectoralis major¹ and trapezius flaps,^1-4 were the mainstay of reconstruction. They offer good bulk and reliable vascularity but come with limitations stemming from their arch of rotation, as well as from possible diminished upper extremity or shoulder function postoperatively. In addition, in some patients, the bulk of the pectoralis major muscle as it courses through the neck may result in poor functional and cosmetic outcomes, as well as the possible limitation of the superior extension of the flap.

With the advancement of microvascular surgery and free tissue transfer during the past 3 decades, additional methods for reconstruction of the lateral skull base have been described. Rectus abdominis, latissimus dorsi, anterolateral thigh, and even radial forearm free flaps have been advocated.^5,6 These flaps provide excellent soft tissue and skin reconstruction but can result in significant donor site morbidity and increased operative time,⁷ which can be a significant consequence for patients with poor underlying health status.^8,9

This article describes the use of the occipital scalp rotational flap for reconstruction after lateral skull base surgical procedures. The occipital scalp rotational flap is an inferiorly based fasciocutaneous flap that receives its vascular supply from the occipital artery or one of its branches. Previous descriptions of this flap have primarily been of reconstruction after posterior scalp skin cancer resections^10,11 or burn surgery.¹² Additional applications, such as in procedures to treat alopecia^13,14 and rotation to fill neck defects from wound breakdown following salvage procedures,¹⁵ have been reported. With advantages such as expeditious flap harvest and minimal donor site morbidity, reconstruction with an occipital flap can be desirable for patients with significant medical comorbidities that would otherwise limit their ability to undergo more traditional methods of reconstruction.

Approval was obtained from the Massachusetts Eye and Ear Infirmary and Saint Louis University Hospital's internal review board. A retrospective medical record review was performed for all patients who underwent reconstruction with an occipital scalp rotational flap after surgical resection of invasive tumors of the auricle, external auditory canal, and/or temporal bone at our institutions from January 1, 1998, to December 31, 2005. Patient variables included age, preoperative ASA (American Society of Anesthesiologists) classification (as determined by the attending anesthesiologist just before the operation), total operative time (from skin incision to skin closure, including the resection and reconstructive portions of the procedure), total length of hospital stay (in days), and use of preoperative and postoperative radiotherapy. Additional patient information, including sex, pathologic diagnosis, extent of surgical resection, and medical comorbidities, was also recorded. Clinical outcomes included medical complications, minor and major wound complications, and donor site complications. Minor wound complications were classified as wound breakdown requiring only dressing changes or a minor local revision procedure for treatment, resulting in no delay in the implementation of adjuvant therapy. Major wound complications included hematoma formation, significant wound breakdown resulting in exposed dura or major neurovascular structures, osteomyelitis, meningitis, or other complications requiring a major revision procedure or otherwise delaying initiation of adjuvant therapy.

The procedure for harvesting the occipital scalp rotational flap is as follows. The extent of the skin incision depends on the size of the defect as well as the extent of the anterior incision that continues onto the neck (Figure, A and B). The incision is carried down through the skin and subcutaneous tissues to the subgaleal, suprapericranial plane and is then elevated from an anterosuperior to posteroinferior direction. The course of the occipital artery and its branches can usually be seen directly or identified using a Doppler signal. As the dissection approaches the superior nuchal line and the occipital protuberance, especially near the posterior insertion of the sternocleidomastoid muscle, care must be taken to directly visualize the occipital vascular pedicle. In this region, the vessels pierce the cranial fascia of the sternocleidomastoid and trapezius muscles and travel from the posterior neck superiorly into the superficial fascia of the scalp.

Before rotation of the fasciocutaneous flap, an abdominal fat graft can be used to obliterate most of the lateral temporal bone defect. This results in a better cosmetic outcome and allows for more soft tissue coverage of the middle ear and mastoid contents. The raised occipital flap can then be rotated and sutured into place (Figure, C). The resulting posterior defect can be reliably covered with a split-thickness skin graft (Figure, D). In patients who only underwent an auriculectomy, the abdominal fat graft was not used.

The mean (SD) patient age at the time of the procedure was 73.9 (12.0) years. The mean preoperative ASA classification was 2.8 (0.4). For 2 patients (patients 5 and 7), the ASA classification assigned by the attending anesthesiologist was inconsistent with the patient's medical history; both patients were classified as ASA 2 despite having a history of coronary artery disease. These 2 patients were reassigned an ASA classification of 3 at our discretion (Table). The mean (SD) operative time was 8.1 (2.3) hours, and the mean length of hospital stay was 5.3 (1.8) days. Three patients received preoperative radiotherapy, and 7 received postoperative radiotherapy; 1 patient (patient 5) received radiotherapy preoperatively and postoperatively. One patient (patient 9) did not receive any radiotherapy.

Two patients developed medical complications in the postoperative period. One developed a non-ST–segment elevation myocardial infarction that was managed with conservative medical intervention. Another patient was readmitted to the hospital for constipation and dehydration 2 days after discharge. In the postoperative period, 2 patients developed minor wound complications. Patient 5 had external auditory canal stenosis requiring revision canaloplasty with split-thickness skin graft 5½ months postoperatively, followed by osteoradionecrosis and minor wound breakdown that required a revision scalp rotational flap procedure with split-thickness skin grafting for closure of the defect 9 months postoperatively. Patient 7 had 15% flap loss resulting in exposure of the underlying fat graft and a small amount of mastoid bone. This wound healed completely with wet-to-dry dressing changes. There were no major wound complications. Patient 10 had a 30% to 40% area of nontake of the split-thickness skin graft used to close the posterior scalp donor site defect. This was treated with a revision of the local flap closure.

Of note, patient 1 did not have an occipital flap reconstruction at the initial resection but rather 6 weeks postoperatively to repair an area of wound breakdown after primary closure over a fat graft. In addition, patients 4 and 8 underwent an auriculectomy as their only ablative procedure. As a result, data from these 3 patients were excluded from the calculation of mean operative time and mean length of hospital stay.

The surgical defect following tumor resection of the lateral skull base provides a significant challenge. Given the size and location of the defect and the potential need for postoperative radiotherapy, it is essential to provide adequate soft tissue coverage to the area to avoid serious consequences that can result from wound breakdown and exposure of underlying structures.

Before the advent of free tissue transfer, the frontline option for reconstruction after a lateral skull base resection was the use of regional myocutaneous flaps that could be rotated on an intact vascular pedicle. The pectoralis major flap provides excellent soft tissue and cutaneous coverage but has limitations based on its arch of rotation and pedicle length that can lead to an inability to reach the superior aspect of the defect. In addition, postoperative complications such as partial or complete flap failure, hematoma, seroma, atalectasis, and decreased upper extremity function can result.¹⁶

The lower island trapezius flap is another rotational flap frequently used for reconstruction after lateral temporal bone resection. Consistently based on a descending branch off the transverse cervical vessels, this flap similarly allows for effective soft tissue and skin coverage in a single stage. However, since the pedicle vascularity courses through the base of the neck and may have been included in a previous surgical field or radiation portal, flap breakdown can occur. In a series of 14 lower island trapezius flap reconstructions after lateral skull base resection, 3 patients had major flap loss with breakdown of the skin paddle that required a revision procedure.⁴ The length of the procedure may also be increased when using the trapezius flap owing to repositioning of the patient.

During the past 30 years, the development of microvascular surgery for use in head and neck reconstruction has expanded the field and has become the mainstay of treatment.⁶ Advantages of free tissue transfer include a wide variety of donor sites allowing the reconstructive surgeon to select the most appropriate soft tissue bulk and skin paddle to match the defect. In addition, because of the distant location of most donor sites from the head and neck, it is usually possible to use a 2-team approach to minimize the overall anesthesia time for the patient. Not only this, but the restrictions of pedicle architecture and arch of rotation often encountered with regional myocutaneous flaps are avoided and the resulting tethering effect and cosmetic deformity can be minimized. Finally, the flap failure rate is frequently reported as less than 7%.^17-20 Despite these advantages, however, there are patients for whom free tissue transfer may not be the most appropriate choice for reconstruction, such as those who have advanced medical comorbidities and have already undergone a prolonged ablative procedure.

In a retrospective review of 200 consecutive microvascular free tissue transfers, Singh et al⁹ found that prior local radiotherapy, anesthesia time of more than 10 hours, and advanced Charlson comorbidity index scores were associated with an increased risk for the development of perioperative and postoperative complications. In addition, advanced Charlson score and age older than 70 years correlated with increased complication severity. In this same population, age older than 70 years was not an independent risk factor, but when it was associated with an operative time of more than 10 hours it was found to be associated with an increased number of systemic complications. Complications in their study population resulted in a median increased length of hospital stay of 7.5 days. In our study, the patient who had an operative time longer than 10 hours (patient 2) was the only one to develop an immediate postoperative medical complication, in the form of a non–ST-segment elevation myocardial infarction.

In a separate study by Serletti et al,⁸ patients with an ASA classification of 3 or 4 had a higher rate of medical complications, but not surgical complications, after free flap reconstruction. In these same patients, prolonged operative time, especially when longer than 10 hours, was associated with an increased occurrence of surgical complications. Age was not found to be an independent risk factor for patients undergoing free tissue transfer. In addition, when comparing free tissue transfer with pedicled flaps for reconstruction of composite head and neck defects, patients who underwent free flap reconstruction had a significantly longer operative time (9 hours 35 minutes vs 4 hours 58 minutes) and length of intensive care unit stay (1.4 days vs 0.1 day), as well as significantly greater total hospital charges ($53 585 vs $32 984).⁸ Many of these discrepancies may be contributing to, or resulting from, postoperative complications.

We report a series of 10 consecutive occipital scalp rotational flaps that resulted in a successful, safe closure of lateral skull base defects. The occipital vascular pedicle provides a reliable blood supply to a sturdy fasciocutaneous closure, which, when used in combination with an abdominal fat graft, provides adequate soft tissue bulk for the surgical bed. Moreover, when compared with regional musculocutaneous flaps, and especially free flaps, the occipital flap allows for a greater ease of flap harvest and donor site closure.

Our patient population was relatively old (mean age, 73.9 years), and most had significant medical comorbidities (8 patients had a preoperative ASA classification of 3). According to previously published studies, these patients may have been at higher risk for developing postoperative medical or surgical complications, especially if their anesthesia time was more than 10 hours. For our group, the mean operative time was limited to 8.1 hours, with only 1 patient requiring an operative time of longer than 10 hours. Of 10 patients, 2 had minor wound complications. These findings, although they come from a small patient population, compare favorably with what has been described for other reconstructive modalities for the head and neck.^4,8,9,16

Despite the success of the occipital flap in our patient population, there are limitations to the technique. First, shifting the hair-bearing skin can be a cosmetic problem, not only because of the rearrangement of scalp and the alopecia at the donor site but also because of interference with the placement of an auricular prosthesis in the future, especially in individuals who will not receive radiotherapy postoperatively. In addition, in individuals who undergo a concomitant neck dissection at the time of their reconstruction, the reliability of the occipital flap vascularity may be diminished. In both individuals in our study who developed minor wound complications, a neck dissection, including removal of lymph nodes in levels IIa and IIb, was performed at the time of the tumor resection and reconstruction. Although the operative reports did not describe the integrity of the occipital artery postoperatively, it is possible that a lymphadenectomy from level II may reduce the reliability of the flap's blood supply. In our study, 2 of 4 patients who had a neck dissection including removal of level II lymph nodes as part of their procedure subsequently had minor wound complications, compared with no wound complications in the 6 patients who did not have neck dissections. However, even in the setting of occipital artery sacrifice, it is likely that the associated fasciocutaneous flap can survive on random blood supply if designed correctly and used in the appropriate clinical setting. Individuals who have received prior radiotherapy, and those who have vascular disease or other complicating factors that will otherwise adversely affect wound healing, may not be candidates for an occipital flap reconstruction if a neck dissection was done at the time of the procedure.

Given that this is a retrospective observational study, no direct comparisons were made among outcomes of patients receiving the occipital flap, rotational myocutaneous flaps, and free flaps. This may be the subject of future study. However, it is reasonable to assume that patients receiving the occipital flap reconstruction would have a reduced reconstructive operative time, a shorter hospital stay, and a reduction in donor site morbidity, compared with patients undergoing regional and free flap reconstructions.

In patients with invasive tumors of the ear and temporal bone, the underlying oncologic disease process often leads to a poor prognosis and limited life expectancy. In these patients, especially among those with significant medical comorbidities, it may be appropriate to opt for a more expeditious and less morbid reconstructive modality. This observational study provides evidence that the occipital scalp rotational flap is reliable and is one such option that should be considered in select patients.

Correspondence: Michael G. Moore, MD, Massachusetts Eye and Ear Infirmary, Department of Otolaryngology–Head and Neck Surgery, Harvard Medical School, 243 Charles St, Boston, MA 02114.

Submitted for Publication: May 23, 2007; final revision received August 22, 2007; accepted August 28, 2007.

Author Contributions: Drs Moore and Lin had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. Study concept and design: Moore, Lin, and Varvares. Acquisition of data: Moore, Lin, Mikulec, and McKenna. Analysis and interpretation of data: Moore, Lin, and Varvares. Drafting of the manuscript: Moore and Lin. Critical revision of the manuscript for important intellectual content: Moore, Lin, Mikulec, McKenna, and Varvares. Study supervision: Moore, Lin, Mikulec, McKenna, and Varvares.

Financial Disclosure: None reported.

Previous Presentation: The results of this study were presented at the 17th Annual Meeting of the North American Skull Base Society; February 18, 2006; Phoenix, Arizona.