Submental flap as an alternative to microsurgical flap in intraoral post-oncological reconstruction in the elderly

Dihydromyricetin regulates KEAP1-Nrf2 pathways to enhance the survival of ischemic flap

In clinical flap practice, there are a lot of studies being done on how to promote the survival of distal random flap necrosis in the hypoxic and ischemic state. As a traditional Chinese medicine, dihydromyricetin (DHM) is crucial in preventing oxidative stress and apoptosis in a number of disorders. In this work, we examined the impact of DHM on the ability to survive of ischemia flaps and looked into its fundamental mechanism. Our results showed that DHM significantly increased the ischemic flaps' survival area, encouraged angiogenesis and blood flow, reduced oxidative stress and apoptosis, and stimulated KEAP1-Nrf2 (Kelch-like ECH-associated protein 1-nuclear factor erythroid 2-related factor) signaling pathways. Adeno-associated virus (AAV) upregulation of KEAP1 expression also negated the favorable effects of DHM on flap survival. By activating KEAP1-Nrf2 signaling pathways, DHM therapy promotes angiogenesis while reducing oxidative stress and apoptosis.

Submental Artery Island Flaps (SAIF) for Oral Cavity Cancer: Surgical Technique and Tertiary Care Experience

In oral cancer surgeries, oncological outcomes take precious driverseat. But the copassengers like reconstruction, cosmesis, swallowing and speech outcomes deserve equivalent importance. Submental Artery Island Flaps (SAIF) provide an underutilized and extremely versatile option for reconstruction of defects following early stage oral cavity tumour resections. In this prospective observational analysis, we describe the technique, challenges and outcomes of SAIF at our tertiary care institute. Sixteen patients with Stage I and II oral cavity cancers were enrolled between June 2020 to May 2021. Verrucous carcinomas were five and well differentiated carcinomas were 11 patients. After tumour excision and neck dissections, defects were reconstructed with Pedicled submental flaps. Complications and functional outcomes were analyzed over two years. Nineteen percent were ladies and 81% were gentlemen. Median age was 52 years. Tongue tumours formed majority with 56% cases. Largest skin paddle taken was 36 cm2. Flap survival was 88%. There were variations in venous drainage of flaps which have been depicted in case figures. There was no report of orocutaneous fistula. Grade 3-4 speech satisfaction was achieved by 81.2% patients at 6 months. Swallowing was excellent, grade 4-5 for 100% of patients at 6 months. One patient had distant metastasis at 7 months and died. SRLR (Submental flap Recurrences) and trismus were zero percent at two years. The unexplored field of submental flaps can be used for oral cancer reconstructions in a versatile way. Donor site easy closures, no scars on face, early resumption of daily activities and short hospital stay makes it one of the ideal options in early stage oral cavity defects.

Preservation of the Nerve to the Mylohyoid Muscle During Submental Island Flaps: An Anatomic Feasibility Study for Facial Nerve Reanimation Procedures

The submental island flap is an axial pattern pedicle flap widely used in head and neck surgery because of its ease and success. Indications of the submental island flap range from reconstruction for the malignant tumor resection to loss of temporal bone and facial skin due to trauma. Whereas, intraoperative facial nerve injury is not uncommon. We verified whether it was possible to localize the nerve to the mylohyoid muscle and reanimate the facial nerve during submental island flap procedures by preserving the mylohyoid muscle using human fresh cadaveric specimens. Six cadaveric heads were dissected and the position of the nerve to the mylohyoid muscle identified to the mylohyoid triangle documented. We identified the nerve to the mylohyoid muscle on all sides within the mylohyoid triangle and were able to separate the nerve from the submental island flap completely. Our results suggest that facial nerve reanimation using the nerve to the mylohyoid muscle can be used while reconstructing with a submental island flap in cases of intraoperative facial nerve injury.

The contralateral-based submental artery island flap: feasibility and oncological safety in oral cancer-related defect reconstruction

OBJECTIVES

Oncologic risk is a serious concern of submental artery island flaps. Here, we introduce the contralateral-based submental artery island flap (C-SAIF) and demonstrate its feasibility and long-term oncological safety in reconstructing oral cancer-related defects.

METHODS

An anatomical study was performed concentrating on the pedicle length in seven cadavers. Then, a retrospective study was carried out on C-SAIF patients operated on by a single team. The standard surgical technique of C-SAIF was conducted. Outcomes including operative time, length of hospital stay, volume of intraoperative blood loss, and scores of the Multidisciplinary Salivary Gland Society (MSGS) questionnaire were compared with a similar cohort reconstructed with anterolateral thigh free flap (ALTF). In addition, oncological outcomes were evaluated by the 5-year cumulative survival rate between C-SAIF and ALTF patients.

RESULTS

The pedicle length of C-SAIF was sufficient for the flap to be extended to the contralateral oral cavity. Fifty-two patients were included in the retrospective study, and nineteen of them underwent reconstruction with C-SAIF. The operative time of C-SAIF was shorter (p = 0.003), and the intraoperative blood loss was less (p = 0.004) than that of ALTF. There was no difference in MSGS scores. The results of survival analysis revealed comparable survival curves for the two groups in terms of overall survival, disease-specific survival, and disease-free survival.

CONCLUSION

C-SAIF is a feasible and reliable flap for reconstructing oral cancer-related defects. Moreover, it is an effective island flap to preserve the perforator and pedicle without compromising oncological safety.

Oncologic safety of the pedicled submental island flap for reconstruction in oral tongue squamous cell carcinoma: An analysis of 101 cases

OBJECTIVE

To evaluate whether the pedicle submental island flap (SIF) can be safely used in the oral tongue squamous cell carcinoma (OTSCC) patients with pathologically node-positive (pN+) neck, especially pN+ at level I.

METHODS

Retrospectively, 101 OTSCC patients with SIF reconstruction were enrolled. Oncological outcomes included the total locoregional recurrence, the SIF related locoregional recurrence (SRLR) which referred to the local recurrence at flap and ipsilateral neck recurrence at level I, recurrence free survival (RFS), overall survival (OS), and disease specific survival (DSS).

RESULTS

Sixty-one patients were pathologically node-negative (pN0) and 40 were pN+. Thirteen patients experienced locoregional recurrence, of which 5 had a SRLR. The pN+ group had a significantly higher locoregional recurrence rate, lower 5-year RFS, OS and DSS than pN0 group (P < 0.05). Patients with pN0 had a significantly higher neck RFS when compared to those with pN+ either at level I (P = 0.005) or at other levels (P < 0.001). However, the neck RFS was similar between the two subgroups of pN+ (P = 0.550). Especially, patients with pN+ at level I had a significantly higher SRLR rate (P = 0.006) compared to those with pN0 at level I. Multivariate analysis showed that pN+ was an unfavorable factor for tumor recurrence and OS.

CONCLUSION

Our data did not support the use of SIF in OTSCC patients with pN+ neck at level I due to an significantly increased SRLR rate compared to those with pN0 neck at level I.

Dermal Substitutes and Skin Grafts in the Reconstruction of Post-Traumatic Total Scalp Avulsion: A Case Series

Although scalp defects can vary in size and thickness, scalp avulsion represents a rare occurrence. This type of lesion may have different origins, but it is usually related to long hair being caught in agricultural machinery. The management of full-thickness scalp defects poses a challenge to the head and neck surgeon due to the possible involvement of neurovascular structures and scar retraction, which can affect the esthetic restoration of the area. Several algorithms for the choice of scalp reconstruction have been proposed in the literature and different techniques are available for extensive scalp defect reconstruction (local soft tissue flap, microvascular free flap, and skin graft combined with dermal substitutes), based upon the scalp defect type. Here we describe six cases of patients with total scalp avulsion, which required a combined reconstruction with a split-thickness skin graft (STSG) and Integra® matrix immediately after the trauma.

Colgajo submentoniano en la reconstrucción de cabeza y cuello

Introducción. Los colgajos del territorio de la arteria submentoniana pueden ser utilizados como un colgajo cutáneo, musculofacial y osteocutáneo, realizando cierres primarios del defecto del sitio donante, sin generar defectos funcionales ni estéticos mayores. Métodos. Describir la experiencia de nuestro equipo quirúrgico, las complicaciones relacionadas con el uso del colgajo y los resultados oncológicos, así como los desenlaces tardíos durante el seguimiento de los pacientes incluidos en el estudio. Resultados. Se incluyeron veintiún pacientes, con una edad media de 66 años (rango 52 - 86), con patología oncológica de lengua, labio inferior, paladar blando, nariz, órbita y orofaringe. Todos los pacientes fueron sometidos a disección selectiva ipsilateral del cuello, tras la extracción del colgajo y en todos los casos se preservó el nervio mandibular marginal. Se registraron complicaciones como la necrosis parcial. La estancia hospitalaria media fue de 8 días. Conclusiones. El colgajo de la arteria submentoniana ha mostrado resultados favorables debido a su uso versátil, amplio arco de rotación, color y baja morbilidad del sitio donante. Se recomienda realizar estudios más robustos, que incluyan la experiencia de diversos especialistas en países que compartan las mismas limitaciones técnicas y características sociodemográficas.

Reconstruction of lower and midfacial soft tissue defects with a submental island flap

This study aims to analyze the feasibility and utility of a submental island flap and to identify whether this flap procedure is a good choice for the reconstruction of lower and midfacial soft-tissue defects. This was a retrospective study that included 12 patients with lower and midfacial soft tissue defects, which were reconstructed using the submental island flap technique. The medical records of 12 patients who underwent reconstruction with submental island flaps from September 2015 to September 2020 were reviewed and included 11 patients with skin cancer and 1 patient with a history of trauma. The mean age of the patients was 64.9 years. The details of the flap harvest were studied for flap size, the procedure to elevate the flap, pedicle flow, and flap survival rate. In addition, information on demographics, histology, location, size, recurrence, and outcomes was recorded. All of the flaps survived. The skin paddle size ranged from 22 to 55 cm² (mean size 33 cm²). Ten flaps were anterograde pedicle flaps and two flaps were retrograde pedicle flaps. All donor sites were closed using primary closure without any difficulty in neck movement. None of the patients had symptoms of postoperative facial palsy. There were no signs of any local or regional cancer recurrence. The mean follow-up time was 22.9 months. There was an esthetic appearance of graft sites. The submental island flap is a feasible and reliable option for the reconstruction of lower and midfacial defects, which provides good cosmetic results.

Fasciocutaneous Type Axial Pattern Local and Regional Flaps: Alternative to Free Flaps?

Emerging usage of carefully harvested, pedicled, local and regional, skin, mucosal, and myomucosal island has a potential to save operating time and resources. Presented here are two such flaps which serves as work horses for moderate defects of the oral cavity, i.e. the islanded nasolabial and facial artery myomucosal flaps, and the technical considerations advocated by the author.

Outcomes of patients with minor salivary gland mucoepidermoid carcinoma of the palate undergoing submental flap reconstruction following radical resection

OBJECTIVE

To investigate the outcomes of patients with mucoepidermoid carcinoma of the palate undergoing pedicled facial-submental artery island flap (FSIF) reconstruction following resection.

PATIENTS AND METHODS

41 patients with early stage disease and 9 patients with advanced-stage disease underwent radical excision and neck dissection. 37 IIb, 4 class IIa and 9 IIIb maxillary defects were reconstructed with FSIF, folded FSIF or folded FSIF with titanium mesh respectively. The skin paddles were 3 × 8 to 5 × 15 cm and 3 × 8 to 5 × 14 cm, respectively. 5 patients with high grade disease were treated with cobalt 60 adjuvant radiotherapy after operation.

RESULTS

One flap failure occurred, yielding a success rate of 98.0% in the reconstruction of palate II and III defects with FSIF or titanium mesh. The patients were seen for follow-up for 16-60 months postoperative. 76.0% patients alive with no disease (AND); 14.0% patients alive with disease (AD) and 10.0% died of disease (DD). Rates of AND, AD and DD differed significantly according to histopathologic grade and TNM stage (P < 0.001); rates of AND, AD and DD differed obviously according to necrosis of the tumors lymph node metastasis, and tumour cell anaplasia and treatment (P < 0.05).

CONCLUSIONS

Radical resection with wide safety margins of normal tissues including neck dissection is the mainstay of treatment modality. The patients with high grade disease should be treated with postoperative radiotherapy. The FSIF is a reliable and safe method for repairing Brown class II maxillary defects.

Reconstruction of a Giant Congenital Melanocytic Nevus Defect With a Submental Flap in a Global Health Setting

Excision of a facial congenital melanocytic nevus (CMN) is a common reason for consultation in pediatric plastic surgery. Facial nevi are generally small and uncomplicated to remove and become more complex when large or giant. The available resources determine treatment and excision options. The indication for excision is generally based on esthetic criteria; however, the risk of melanoma increases with the nevi diameter. This patient with a giant CMN (GCMN) was encountered on an international medical mission trip. The palm-sized lesion spanned from her left zygomatic arch down to the jawline. Due to the esthetic impact and lack of resources to continue monitoring the lesion, complete excision was performed. The resultant defect was reconstructed with a pedicled submental flap. This article presents management and reconstruction of a facial GCMN encountered in the global setting and presents a brief literature review of GCMN.

Oncologic safety of submental island flap reconstruction in clinically node-negative oral cancer patients: a prospective comparative study

The purpose of this study was to evaluate the oncologic safety of submental island flap (SIF) reconstruction in clinically node-negative oral cancer patients. Forty-four clinically node-negative oral cancer patients with tumour size T1-T3 were divided into two groups. The Submental group consisted of 21 patients, who underwent submental island flap reconstruction whereas the control group consisted of 23 patients who underwent reconstruction with other locoregional or free flaps. The locoregional recurrence rate (LRR) and recurrence-free survival (RFS) in these two groups were assessed and compared. The follow-up period in the two groups ranged from six to 28 months, with a median follow-up period of 15 months and 21 months, respectively. Results showed that the LRR in the control and the submental group was 21.7% and 19%, respectively (p = 0.825). Kaplan-Meier curve showed that the difference in recurrence-free survival in the two groups was not statistically significant (p = 0.749). Multivariate and bivariate analyses did not establish any relationship between the predictive parameters and locoregional recurrence. Thus, the Submental island flap is a reliable and versatile locoregional flap for the reconstruction of post-resection defects in oral cancer. It has no predictive influence on locoregional recurrence in clinically node-negative oral cancer patients.

Submental Artery Island Flap in Oral Cavity Reconstruction. An Observational, Retrospective Two-centre Study

Introduction  The submental flap provides an alternative technique in orofacial reconstruction, especially in situations in which free flaps are not available, or the patients are unfit. Objective  To demonstrate the oncological safety and benefits of this flap in oral cavity reconstruction. Methods  A total of 14 patients with oral cavity cancers, who underwent submental flap reconstruction from January 2016 to January 2018, were included in the study. Results  There were 11 male and 3 female patients with a mean age of 66.7 ± 14 (Min: 52/Max: 91) years old. The most common primary tumor site was the mobile tongue in 12 (85.7%) patients. All of the patients underwent ipsilateral selective neck dissection after the flap was harvested. Flap partial necrosis was observed in one patient, and total necrosis in another one. The mean follow-up was of one year. Nonlocal or regional recurrences were observed. Conclusion  Submental island flap represents a good option in oral cavity reconstruction in a restricted setting or in patients considered not fit for free flap reconstruction. Preoperative selection of clinically neck node-negative patients is essential due to the potential risk of occult metastasis.

Submental flap: Game changer in oral cancer reconstruction-A study of 1169 cases

BACKGROUND

Free-flap reconstructions (FFRs) are the standard-of-care following resections for oral cancer. This study assessed an alternative, the pedicled submental flap (SF) for its versatility, oncological outcomes, and comparative operative time and cost.

METHODS

This was a longitudinal prospective study of 1169 patients of oral cancer reconstructed with the SF. Oncological outcomes in terms of recurrence rate and disease-free survival (DFS), were analyzed in 730 cases with a minimum of 18 months follow-up. Surgical time and cost were compared between 20 SFs and 14 FFRs performed consecutively.

RESULTS

SF was used to reconstruct defects in the cheek (29.2%), mandible (41.6%), tongue (26.3%) and palate (2.7%) with a 94% flap survival. N+ at level 1 did not adversely affect the recurrence rate as compared with N+ at levels other than level 1 (27.52% vs 29.81%). SFs took a shorter time (186 minutes vs 474 minutes) and cost significantly less than FFRs (P < .0001).

CONCLUSIONS

SF can reconstruct various oral defects, is sturdy, and esthetically and functionally satisfactory. The procedure time is much shorter than for FFR and costs considerably less. With careful case selection and meticulous clearance, SF reconstruction is oncologically safe even in N+ neck.

The contralateral based submental island flap for reconstruction of tongue and floor of mouth defects: Reliability and oncological outcome

BACKGROUND

Submental artery island flap (SIF) is a viable alternative to free flaps for selected oral-cavity defects, however, concerns about its oncologic safety still exists. A novel harvesting technique and its outcome is described in here.

METHODS

This is a prospective study for patients with lateralized oral tongue and/or floor of mouth (FOM) cancers who undergone reconstruction using pedicled SIF based on contralateral submental vessels (CSIF) following resection.

RESULTS

Forty-one patients were included. Twenty-four patients had T2, 13 had T3, and 4 had T1 tumors. The largest flap skin paddle was 15 × 9 cm. One patient sustained complete and five sustained partial flap loss. Three patients developed tongue tethering. Median follow-up was 13.6 months. Locoregional recurrence occurred in 11 patients (26.8%); 6 oral-cavity recurrences (14.6%), 6 ipsilateral, and 1 contralateral neck recurrences (2.4%).

CONCLUSION

CSIF is a reliable flap that addresses the oncologic controversy and overcomes the disadvantages of ipsilateral flap.

Vertical Submental Island Flap for Head and Neck Reconstruction

Regional flaps remain a cornerstone of head and neck reconstruction. Among their many functions, they serve a vital role in salvage surgery and for those in whom medical comorbidities preclude the use of microvascular free flaps. Recent research has also examined their potential benefit in value-based healthcare metrics such as operative time, cost, intensive care unit care, and length of stay as compared to free-flap reconstruction. The submental island flap is one such entity that is well described and validated to provide predictable, oncologically sound coverage for defects of the lower third of the face and oral cavity. Its application has also been documented for repair of defects of the midface, temporal region, oropharynx, and hypopharynx, albeit less frequently. Since its original description, there have been several modifications of this axial-based flap, though none of a vertically oriented long axis. We describe a case of a vertically based submental island flap for maxillary reconstruction that allowed for debulking and recontouring of prior pectoralis flap and correction of submental ptosis.

Hand Doppler flowmetry for surgical planning of pedicled flap in extensive full-thickness scalp reconstruction

Reconstruction of scalp defects can be performed with local flaps for medium to large defects (2-25 cm²) and microvascular free flaps for extensive full-thickness scalp reconstruction greater than 25 cm². Doppler flowmetry with its ability to exactly mark the course of arteries on the overlying skin, is a useful tool for the surgical planning of large local flaps. In our retrospective study conducted on 38 patients (all patients had malignancies or post-traumatic scalp defects), consisting of 39 total surgical procedures, we studied the impact of doppler ultrasonic flowmetry in the surgical planning for pedicled flaps in extensive full-thickness scalp reconstruction (>25 cm²) by evaluating overall flap survival rate. Nine different types of local flaps were employed in the scalp reconstruction: Superficial temporal artery (STA) pedicled rotation flap, STA pedicled transposition flap, STA islanded flap, bipedicled STA flap, bipedicled fronto-occipital flap, Supraorbital/Supratrochlear artery rotation flap, Supraorbital/Supratrochlear artery transposition flap, Occipital artery (OA) pedicled rotation flap, OA pedicled transposition flap. Before each surgical procedure a hand held doppler Huntleigh Diagnostic flowmeter with a 8 MHz probe was used to identify and follow the course of the arteries. Flap survival rate was 100%. No postoperative complications related to the flap were reported, while in two patients a partial skin graft failure occurred.

Effect of Prior Radiotherapy on the Outcome of Submental Island Flap in Head and Neck Reconstruction

The submental island flap is a new alternative to the reconstruction of various head and neck defects. But there has been a relative paucity of information about the use of this flap in irradiated patients. The authors present their preliminary experience in the use of this flap in irradiated and nonirradiated patients. Eighty-one patients (53 nonirradiated and 28 irradiated patients) underwent reconstruction with the submental island flap between March 2011 and August 2017. The authors have 13 patients of venous congestion (7 in nonirradiated and 6 in irradiated group), 7 patients of partial necrosis of the flap (4 in nonirradiated and 3 in irradiated group). The authors also have 3 patients of transient paralysis of marginal mandibular nerve (2 in the nonirradiated and 1 in irradiated group), and 2 patients of pharyngo-cutaneous fistula in nonirradiated group. The authors have no cases of total flap loss, permanent paralysis of marginal mandibular nerve but have dehiscence of the submental area after harvesting the flap in an irradiated patient. When combined with the reported experience of other surgeons, the authors' preliminary experience showed that the submental island flap was an excellent alternative in the reconstruction of head and neck defects in both irradiated and nonirradiated patients because of its reliability, versatility, and relatively acceptable complications.

Reconstruction with submental flap for aggressive orofacial cancer- an updated series

PURPOSE

Submental flap is gaining popularity for head and neck reconstruction. We have reported in 2007 our early experience of using submental flap for aggressive orofacial malignancy. Novel flap design and application is described in this updated series.

MATERIALS AND METHODS

15 patients who had received submental flap reconstruction after extirpation of newly diagnosed aggressive orofacial lesions were retrieved. The details of the flap harvest was studied for flap size, inclusion of mylohyoid muscle, antegrade versus retrograde blood supply, and compared with our previous series.

RESULTS

The dimension of flap skin paddle was 30cm² (range 20-72). Retrograde pedicle flow was used in 2(13.3%) patients. Mylohyoid muscle was included in the flap in 6(40%) patients. There was no total flap necrosis while partial flap necrosis occurred in 1 patient(6.7%). There was a significant increase of inclusion of mylohyoid muscle to the flap in this series (p = 0.02). Novel techniques including double-paddled flap skin to resurface full-thickness defect and chimeric osteocutaneous mandible submental flap for maxillary defect were successfully performed.

CONCLUSIONS

Submental flap is a viable reconstructive option in selected patients with aggressive orofacial malignancy. The indications are expanding and its technical modification is evolving and resulting in more innovative applications.

[Research progress of pedicled flaps for defect repair and reconstruction after head and neck tumor resection]

Objective

To summarize the current status of pedicled flaps for defect repair and reconstruction after head and neck tumor resection, and to present its application prospects.

Methods

Related literature was reviewed, and the role evolution of pedicled flaps in the reconstruction of head and neck defects were discussed. The advance, anatomical basis, indications, advantages, disadvantages, and modification of several frequently used pedicled flaps were summarized.

Results

The evolution of pedicled flaps application showed a resurgence trend in recent years. Some new pedicled flaps, e.g., submental artery island flap, supraclavicular artery island flap, submandibular gland flap, and facial artery musculomucosal flap, can acquire equivalent or even superior outcome to free flaps in certain cases. Technological modification of some traditional pedicled flaps, e.g., nasolabial flap, pectoralis major myocutaneous flap, latissimus dorsi musculocutaneous flap, temporalis myofascial flap, and temporoparietal fascial flap, can further broaden their indications. These traditional flaps still occupy an irreplaceable role, especially in patients with poor condition and institution with immature microsurgical techniques.

Conclusion

The pedicled flaps still plays an important role in head and neck reconstruction after tumor resection. In certain cases, they demonstrate some advantages over free flaps, e.g., more convenient harvest, more rapid recovery, less expenditure, and better functional and aesthetic effect.

The Submental Island Flap Is a Viable Reconstructive Option for a Variety of Head and Neck Ablative Defects

BACKGROUND

The submental island flap (SIF) is a pedicled flap based upon the submental artery and vein. Its utility in reconstruction following ablative head and neck procedures has been applied to various subsites including skin, lip, buccal mucosa, retromolar trigone, parotidectomy defects, and tongue. We review our experience using the SIF for reconstruction following tumor ablation.

METHODS

This prospective case series with medical record review includes consecutive patients undergoing SIF reconstruction following ablative surgery for malignancy at a single tertiary care facility between November 2014 and November 2016. We examined preoperative variables, surgical procedures, and postoperative outcomes.

RESULTS

Thirty-seven patients met inclusion criteria. Twenty-nine were male; the average age was 64.3 (±12.4) years. Seventeen cancers involved the oral cavity, 11 involved the skin, 8 were in the oropharynx, and 1 was in the paranasal sinus. The average size of the SIF was 38.8 cm² (±17.6 cm²). Four partial flap losses occurred; none required revision surgery. The average length of stay for these patients was 7.2 (±6.1) days.

CONCLUSION

The SIF is a robust flap that can be reliably used for a variety of head and neck defects following tumor ablation with an acceptable rate of donor- and flap-related complications.