Split temporalis muscle flap anatomy, vascularization and clinical applications

Description of the Pedicled Osteo-Muscular Flap of Split Temporal Muscle

Background

Reconstruction of the head and neck is dominated by free flaps, and for bone reconstruction by fibula and scapula flaps. However, this choice is sometimes difficult to make in patients who cannot tolerate an extensive and lengthy surgical procedure. In addition, vascular micro-anastomoses are sometimes complicated in patients who have been previously irradiated. Pedicle flaps remain an option and can sometimes be considered as first choice for head and neck reconstruction.

Purpose

In this study, we describe the feasibility of a split temporal muscle pedicled flap with coronal harvesting for a reconstruction that can reach the midline.

Study design sample covariates

Ten fresh-frozen human cadaver heads were dissected, and the length of the split flap was noted, followed by the length of the non-split flap.

Results

The mean length was 155.7 mm (± 20.0) for the split flap, from the point of rotation to the tip of the coronoid process. These results coincide with the tragus-midline distance, which makes it possible to consider reconstruction of the midline, especially the maxilla and the mandible, which has not yet been described in the literature.

Conclusions and relevance

This technique would then allow a supply of pedicled vascularized bone for loco-regional reconstruction.

"The Double S" Technique: Subfascial Dissection and Temporalis Muscle Splitting to Prevent Cerebrospinal Fluid Leak and Maximize Surgical Exposure

BACKGROUND

Middle cranial fossa surgery commonly is approached either performing a subtemporal or a pterional craniotomy. To maximize a basitemporal region exposure, an adjunctive bone drilling could be required. In these cases, a watertight dura and temporalis muscle closure are mandatory.

OBJECTIVE

To describe a modified temporalis muscle dissection in middle cranial fossa surgery to increase basitemporal region exposure while assuring a safe and effective closure thus avoiding cerebrospinal fluid (CSF) leakage.

METHODS

A total of 8 patients have been enrolled. Five pterional and 3 subtemporal approaches were performed. In all cases, the novel subfascial muscle dissection and temporalis muscle splitting technique named "the double S technique," was performed to cut up the temporal muscle.

RESULTS

In all cases, a subgaleal drainage was used and removed within 48 hours. No cases of postoperative CSF leak or hematoma collection were reported.

CONCLUSIONS

The double S technique is a safe and effective alternative to enhance the basitemporal region exposure while avoiding the potential, common risk of CSF leak.

Topography of the deep temporal arteries and implications for performing safe aesthetic injections

BACKGROUND

Several studies have started investigating the safety of temporal rejuvenation using soft tissue fillers. However, as the temporal region is highly vascularized, adverse events due to intravascular injection are of primary concern. The scarcity of treatment guidelines to date have focused primarily on avoiding the superficial and middle temporal arteries. The aim of the present anatomical study was to describe the topography of the deep temporal arteries (DTAs) with reference to superficial landmarks, to aid clinicians who perform temporal injections.

METHODS

The tissue layers of eight fresh-frozen cephalic cadavers were dissected and assessed, bilaterally in the temporal region (N = 16). Distance (D) of the anterior (D1 and D3) and posterior (D2 and D4) arteries was measured from (i) the zygomaticofrontal suture line at the lateral orbital rim (D1 and D2) and (ii) the junction of the superior border of the zygomatic arch and lateral orbital rim (D3 and D4). The distance between the anterior and posterior DTAs was also recorded, at the two regions (D5).

RESULTS

Bifurcations of the DTAs were observed in 18.75% (3/16) and 12.5% (2/16) of cases, for the anterior and posterior branches, respectively. On average [mean (standard deviation)], D1 (anterior DTA to the zygomaticofrontal suture line at the lateral orbital rim) = 1.56 cm (0.59); D2 (posterior DTA to the zygomaticofrontal suture line at the lateral orbital rim) = 2.98 cm (0.70); D3 (anterior DTA to the junction of the superior border of the zygomatic arch and lateral orbital rim) = 1.14 cm (0.63); D4 (posterior DTA to the junction of the superior border of the zygomatic arch and lateral orbital rim) = 2.37 cm (0.62); and D5 (distance between the anterior and posterior DTAs) = 1.54 cm (0.68).

CONCLUSION

To help avoid vascular adverse events while performing temporal injections, aesthetic clinicians should be conscientious of safety implications related to the anatomical location of the DTAs and their ramifications.

Temporal Flaps in Head and Neck Reconstructive Surgery: A Systematic Review of Surgical Techniques

The temporal region is a great source of vascularized flap, providing extremely variable and versatile options for reconstruction in head and neck surgery. Its popularity has led to the conception of a large variety of different flaps, in terms of contents and design. Temporal flaps are highly pliable and flexible, providing adequate bulk to obliterate dead spaces and improving engraftment, thus facilitating wound healing. The need to access different anatomical compartments, often far from the original flap anatomical site, has led surgeons to develop techniques to enlarge pedicles and bulk, by reverting and splitting flaps' contents, as well as through partial mandibular and zygomatic resection. To further increase versatility, a multilayered combination of different regional tissues and muscle segmentation techniques has been described. Historically, each flap has had its own proponents and opponents, but a pointy review systematizing techniques and comparatively analyzing different flaps was still missing in the literature. The field of use of some flaps has been progressively limited by the increasing relevance of free tissue transfers, which nowadays may provide success rates up to 95% with a constrained morbidity, thus offering an effective alternative, when available. Given the wide range of reconstructive strategies based on temporal flaps, there is still a great debate on nomenclature and surgical techniques. The present study systematizes the topic, classifying regional flaps according to contents and indications. Harvesting techniques are described stepwise and schematically illustrated, thus offering an indispensable tool to the armamentarium of reconstructive surgeons.

Transinfratemporal Fossa Transposition of the Temporalis Muscle Flap for Skull Base Reconstruction after Endoscopic Expanded Nasopharyngectomy: Anatomical Study and Clinical Application

Objective Temporalis muscle flap (TMF) is widely used in traditional skull base surgery, but its application in endoscopic skull base surgery remains rarely reported. We aimed to investigate the surgical anatomy and clinical application of TMF for reconstruction of skull base defects after expanded endoscopic nasopharyngectomy.

Methods Nine fresh cadaver heads (18 sides) were used for endoscopic dissection at the University of Pittsburgh School of Medicine in the United States. TMF was harvested using a traditional open approach and then transposed into the maxillary sinus and nasal cavity through the infratemporal fossa using an endoscopic transnasal transmaxillary approach. TMF length was then measured. Moreover, TMF was used for the reconstruction of skull base defects of six patients with recurrent nasopharyngeal carcinoma after expanded endoscopic nasopharyngectomy.

Results The length of TMF harvested from the temporal line to the tip of the coronoid process of the mandible was 11.8 ± 0.9 cm. The widest part of the flap was 9.0 ± 0.4 cm. When TMF was dislocated from the coronoid process of the mandible, approximately another 2 cm of reach could be obtained. When the superficial layer of the temporalis muscle was split from the deep layer, the pedicle length could be extended 1.9 ± 0.2 cm. TMF could cover skull base defects in the anterior skull base, sellar, and clivus regions.

Conclusion TMF can be used to reconstruct skull base defects after endoscopic expanded nasopharyngectomy and can effectively prevent the occurrence of serious complications in patients with recurrent nasopharyngeal carcinoma.

Types of Transnasal Endoscopic Nasopharyngectomy for Recurrent Nasopharyngeal Carcinoma: Shanghai EENT Hospital Experience

Background

Transnasal endoscopic nasopharyngectomy (TEN) has become increasingly used for recurrent nasopharyngeal carcinoma (rNPC); however, there is no report on the definitive resectable contour for TEN according to the latest staging system for nasopharyngeal carcinoma. The aim of this study was to establish the types of TEN for rNPC.

Materials and Methods

A total of 101 rNPC patients underwent TEN from January 2016 to April 2019 at the authors’ institution. TEN was categorized into four types, which included type I (n=40) with resection of the nasopharynx and sinuses; type II (n=10) with lateral extension to the parapharyngeal space; type III (n=40) with lateral extension to the floor of the middle cranial fossa and the infratemporal fossa and superior extension to the orbital apex and the cavernous sinus back to the prevertebral region; and type IV (n=11) with the resection of the involved internal carotid artery following type III. The 2-year overall survival rate (OS) and local recurrence-free survival rate (LRFS) were assessed.

Results

The median time of follow-up was 20 months. Twenty-five patients reoccurred. Nineteen patients died. Independent predictors of outcome on multivariate analysis were recurrent T stage (P = 0.039), types of TEN (P = 0.002) and surgical margin (P = 0.003). The 2-year OS and LRFS was 76.2% and 53.6%, respectively.

Conclusions

The result of TEN in the treatment of rNPC is promising. The types of TEN will provide effective guideline for surgical treatment of rNPC.

Regional Salvage Flap Options in Head and Neck Reconstruction

Microvascular free tissue transfer is the standard in the complex head and neck reconstruction with success rates greater than 95%. Free tissue transfer allows for more versatility in reconstructing complex defects with better tissue match. Failures, however, do occur and subsequent free tissue transfer might not be an option due to either the patients' health or in a vessel depleted neck. In these challenging salvage scenarios, the head and neck reconstructive surgeon must turn to regional flaps for reconstruction. Here, we review multiple regional flap options for salvage head and neck reconstruction.

Scalp thickness as a predictor of wound complications after cerebral revascularization using the superficial temporal artery: a risk factor analysis

OBJECTIVE

Cerebral revascularization using the superficial temporal artery diverts some of the blood supply from the scalp to the brain. This may compromise the blood supply to the scalp and could result in more wound complications.

OBJECTIVE

This retrospective chart review aimed to identify the incidence of, and independent risk factors for, wound complications after cerebral revascularization using the superficial temporal artery.

METHODS

Patients who underwent cerebral revascularization using the superficial temporal artery between January 2003 and February 2017 were studied. Minor wound complications included superficial skin necrosis, and mild wound dehiscence, while major wound complications included full-thickness skin necrosis, deep infection, and osteomyelitis that required additional surgical treatment.

RESULTS

A total of 482 cerebral revascularization procedures using the superficial temporal artery were included. Wound complications developed in 32 cases (6.6% of the total), including 7 classified as major in severity (1.5% of the total). The multivariate analysis revealed diabetes mellitus (odds ratio 4.058, p = 0.001), low body mass index (odds ratio 1.21, p = 0.009), and thin scalp (odds ratio 1.82, p < 0.001) as the main risk factors for wound complications. Every 1-mm increase in scalp thickness was associated with a protective effect on wound complications (odds ratio 0.549).

CONCLUSION

Cerebral revascularization using the superficial temporal artery was associated with a relatively high incidence of wound complications. Diabetes mellitus, low body mass index, and thin scalp were found to be independent risk factors for wound complications. The thickness of the scalp could be a useful predictor of wound complications.

Temporal Muscle Flap as a Treatment of an Extensive Cleft Palate in an Adult Patient

For the management of cleft palate, the surgical approach has been suggested at an early stage even in childhood, varying in the number of interventions. Once the interventions are not performed at appropriate times, such as sequences that may accompany specific psychological, functional, and aesthetic effects. Since it has been indicated, temporal muscle flap is a technique with satisfactory results for a resolution of extensive clef palate in adult patients. The purpose of this paper is reporting a case of temporal muscle flap in the soft and hard palate of an adult with a reconstruction of the donor area with a titanium mesh. A 37 year old male patient with cleft lip/palate, complained of difficulty in speech, chewing, swallowing, and breathing. Clinically, it was observed oroantral communication in the region of the hard and soft palate, with a previous cheiloplasty. A temporal rotation was planned to close the fissure for the treatment. The modified coronal approach was used. Temporal muscle traction and its interposition in the palate region were performed through the tunneling technique, and mass suturing was performed. After 3 years, he presented satisfactory results, with the improvement of the quality of life, as well as the area of exposure. In conclusion, since it has been indicated, temporal muscle flap is a technique with satisfactory results for a resolution of extensive cleft palate in adult patients.

Reconstruction of composite oral cavity defects with temporalis flaps after prior treatment

BACKGROUND

Reconstruction of composite oral cavity defects in the setting of prior surgery and radiotherapy presents a significant challenge. Although free tissue transfer has shown success in such situations, it is not without considerable risk. Regional pedicled flaps may provide a more suitable alternative. In certain patients, however, severe soft tissue fibrosis makes more conventional regional flaps impractical or impossible. In these situations, temporalis flaps (temporalis muscle and temporoparietal fascia flaps) are versatile options for coverage of complex defects.

OBJECTIVE

To report our experience using pedicled temporalis flaps for reconstruction of composite oral cavity defects in patients with significant co-morbidities and prior treatment.

METHODS

Three patients were identified and their medical records were reviewed. Their clinical courses and functional outcomes are described. We include a discussion of the operative technique and relevant literature.

RESULTS

All patients had previously undergone extensive treatment. One patient needed reconstruction after resection of a third head and neck malignancy and two patients presented for treatment of osteoradionecrosis. A temporalis muscle flap was used to reconstruct composite oral cavity defects in two patients and a combined temporalis muscle and temporoparietal fascia flap was used for independent defects in one patient. All flaps survived. Functional status and pain improved or stabilized in all patients. There were no major or minor complications.

CONCLUSION

In previously treated fields, where more conventional flaps are impractical, temporalis flaps are a suitable alternative to achieve a stable healing wound and prevent worsening of functional status.