Calf Perforator Flaps: A Freestyle Solution for Oral Cavity Reconstruction

Characterization of the MSAP Flap in Head and Neck Surgical Oncology: A 3D Cadaveric Study

OBJECTIVES

The medial sural artery (MSA) perforator flap is a versatile free flap. However, the cutaneous perforators are not well characterized. The objectives of this pilot anatomical study were to: (1) visualize in three-dimensions, as in-situ, the origin, course, and distribution of the cutaneous perforators, (2) characterize the number and frequency of the perforators, and (3) quantify mean pedicle length.

METHODS

Thirteen cadaveric specimens were dissected, digitized, and modeled in 3D. Three-dimensional models and dissection photographs were used to determine the origin, course, number, distribution, and pedicle length of MSA perforators.

RESULTS

The most common pattern consisted of three perforators (39% of specimens). The maximum number of perforators identified was four (23%). The majority of specimens (92%) had a cutaneous perforator originating from the lateral branch of the MSA and coursed most frequently in the second (43%) and third (37%) quartiles of the length of the tibia. Mean pedicle length was 19.1 ± 6.9 cm. Perforators originating from the medial branch of the MSA were significantly (p < 0.05) shorter than those from the lateral branch and were found to course only in the first quartile.

CONCLUSION

The 3D models constructed in this study provide a comprehensive overview of the location and course of the perforators, enabling measurement of parameters in 3D-space. Anatomical characterization of the MSA perforator flap using 3D analysis can assist reconstructive surgeons in understanding the relevant anatomy and optimizing the surgical technique for flap harvest.

LEVEL OF EVIDENCE

N/A Laryngoscope, 134:4298-4303, 2024.

[Free medial sural artery perforator flap for reconstruction of hand defects]

OBJECTIVE

Defect reconstruction of the hand by means of the free medial sural artery perforator (MSAP) flap.

INDICATIONS

Reconstruction of full-thickness defects on the hand with a thin non-bulky flap in cases of exposure of functional structures or in combination with simultaneous osteosynthetic procedures.

CONTRAINDICATIONS

Prior surgery at the donor site or progressive peripheral artery occlusive disease. Defect size that exceeds the maximum width of the free MSAP flap for primary closure of the donor site. Lack of patient consent or compliance.

SURGICAL TECHNIQUE

Suitable perforators are identified through a medial incision on the calf. The vascular pedicle is then completely followed subfascially along the gastrocnemius muscle until its source vessel the medial sural artery is reached. Subsequently, the flap design is adapted to the perforator anatomy and the flap is completely elevated. Indocyanine green fluorescence angiography can be used to identify the size of the reliable angiosome.

POSTOPERATIVE MANAGEMENT

Close monitoring of the flap is required for the first 48 hours after surgery. Anticoagulation with low-molecular weight heparin should be administered for thrombosis prophylaxis. The hand can be mobilized on the first day after surgery.

RESULTS

Between May 2017 and March 2022 a total of 16 free MSAP flaps were carried out for hand defect reconstruction. All donor sites were primarily closed. The reconstruction was successful in all cases. In one patient venous thrombosis occurred postoperatively, which was successfully revised. In two flaps, surgical hematoma evacuation was necessary within 24 hours after surgery. Complications or wound healing disorders at the donor site were not observed.

Expanding the Armamentarium of Donor Sites in Microvascular Head and Neck Reconstruction

The field of microsurgical head and neck reconstruction has witnessed tremendous advancements in recent years. While the historic goals of reconstruction were simply to maximize flap survival, optimizing both aesthetic and functional outcomes has now become the priority. With an increased understanding of perforator anatomy, improved technology in instruments and microscopes, and high flap success rates, the reconstructive microsurgeon can push the envelope in harvesting and designing the ideal flap to aid patients following tumor extirpation. Furthermore, with improvements in cancer treatment leading to improved patient survival and prognosis, it becomes increasingly important to have a broader repertoire of donor sites. The present review aims to provide a review of newly emerging soft tissue flap options in head and neck reconstruction. While certainly a number of bony flap options also exist, the present review will focus on soft tissue flaps that can be harvested reliably from a variety of alternate donor sites. From the upper extremity, the ulnar forearm as well as the lateral arm, and from the lower extremity, the profunda artery perforator, medial sural artery perforator, and superficial circumflex iliac perforator flaps will be discussed, and we will provide details to aid reconstructive microsurgeons in incorporating these alternative flaps into their armamentarium.

The Medial Sural Artery Perforator Flap: A Historical Trek from Ignominious to “Workhorse”

Rather than just another “review,” this is intended to be an “overview” of the entire subject of the medial sural artery perforator (MSAP) flap as has been presented in the reconstructive literature from its inception in 2001 until the present, with any exceptions not purposefully overlooked. Unfortunately, the pertinent anatomy of the MSAP flap is always anomalous like most other perforator flaps, and perhaps even more variable. No schematic exists to facilitate the identification of a dominant musculocutaneous perforator about which to design the flap, so some adjunctive technology may be highly valuable for this task. However, if a relatively thin free flap is desirable for a small or moderate sized defect that requires a long pedicle with larger caliber vessels, the MSAP flap deserves consideration. Indeed, for many, this has replaced the radial forearm flap such as for partial tongue reconstruction. Most consider the donor site deformity, even if only a conspicuous scar on the calf, to be a contraindication. Yet certainly if used as a local flap for the knee, popliteal fossa, or proximal leg, or as a free flap for the ipsilateral lower extremity where a significant recipient site deformity already exists, can anyone really object that this is not a legitimate indication? As with any perforator flap, advantages and disadvantages exist, which must be carefully perused before a decision to use the MSAP flap is made. Perhaps not a “workhorse” flap for general use throughout the body, the MSAP flap in general may often be a valuable alternative.

Functional Outcomes of the Medial Sural Artery Perforator Flap in Oral Cavity Reconstruction

BACKGROUND

The medial sural artery perforator (MSAP) flap is an ideal option for reconstruction of oral cavity defects owing to its thin and pliable nature and favorable donor site. Our study presents an assessment of functional outcomes including speech and swallowing in patients with oral cavity tumors reconstructed with MSAP flaps.

METHODS

Patients undergoing MSAP reconstruction for oral cavity tumors between January 2014 and January 2018 were identified from our prospective head and neck cancer database. Functional outcomes were assessed in conjunction with the Speech and Language Team with a minimum follow-up of 6 months. Function (speech and swallowing) was recorded as a performance status scale set up by the assessing health care professional.

RESULTS

A total of 38 patients underwent reconstruction with the MSAP flap over the study period. The patient cohort included 10 female patients and 28 male patients. The age range was from 30 to 78 years, with a mean age of 56.8 years. Complications included 1 flap loss and 1 donor site wound dehiscence.Most patients (84.2%) had intelligible speech at 6-month follow-up and further improvement at 1 year (92.1%). All patients resumed feeding on postoperative day 4, and only 7.8% (n = 3) of the patients required assistance with feeding at 1-year follow-up.

CONCLUSIONS

The MSAP flap provides adequate small-volume replacement for oral cavity reconstructions. Our results indicate that most patients achieve a full diet with no restrictions by 1 year after reconstruction. Most of our patients demonstrated excellent speech with little or no need for repetition in conversation. Over the past few years, this has become the flap of choice for oral cavity reconstruction in our unit.

[Research progress of clinical application of medial sural artery perforator flap]

Objective

To review the research progress of the clinical application of the medial sural artery perforator flap (MSAPF).

Methods

The relevant domestic and abroad literature on the clinical application of MSAPF was extensively consulted, and the research progress were summarized and analyzed in aspect of its definition, anatomical characteristics, clinical application, surgical resection and improvement, and advantages and disadvantages of flaps, etc.

Results

MSAPF has the advantages of relatively constant anatomical position, thin flap texture, long vascular pedicle, large vessel diameter, no sacrifice of main blood vessels, concealed donor site, no hair, and fewer complications; it can carry nerves, tendons, and muscles to construct chimeric flaps to repair three-dimensional wounds; and can also repair wounds with high aesthetic and functional requirements such as hand, foot and ankle, head and neck, etc.

Conclusion

The MSAPF is a versatile, various forms, functional diversification, and three-dimensional flap donor site with various application forms and ideal repair effectiveness.

Extended Use of Chimeric Medial Sural Artery Perforator Flap for 3-Dimensional Defect Reconstruction

BACKGROUND

The medial sural artery perforator (MSAP) flap has become increasingly popular because it is thin and pliable for small to moderate defect soft tissue reconstruction. Furthermore, chimeric MSAP flap, which includes a skin paddle and a separated piece of medial gastrocnemius muscle, allowed more freedom for flap insetting, especially in 3-dimensional defect reconstruction. Here we describe our experience regarding this clinical application.

PATIENTS AND METHODS

From 2007 to 2016, 14 male patients (average age, 46.9 ± 14.4 years) who received either a free or pedicled chimeric MSAP flap were included. Of these 14 patients, 7 received this flap for reconstruction in the head and neck, 2 in the upper extremities, and 5 in the lower extremities. Demographic data were collected and analyzed, and a literature review was performed.

RESULTS

Ten patients received free chimeric MSAP flap, and 4 received the pedicled type. Thirteen of the 14 flaps (92.6%) survived, and 1 failed 2 days later owing to venous insufficiency. Venous congestion-related partial loss occurred in another case.

CONCLUSIONS

The chimeric MSAP flap is a good alternative for deep space obliteration or reconstruction of adjacent but separate defects in both free and pedicled flap design. Donor site morbidity is limited. However, the perforator needs to be mobilized carefully to prevent postoperative venous compromise.

The medial sural artery perforator (MSAP) flap: A versatile flap for lower extremity reconstruction

BACKGROUND

The medial sural artery perforator (MSAP) flap provides a thin, pliable and durable soft tissue reconstruction with adequate pedicle length and low donor morbidity. It is an ideal choice for small-to-moderate defects of the lower extremity, although it does have limitations. We report our experience of the flap in a three-pronged anatomical, clinical and patient reported outcome-based study.

METHODS

Cadaveric fresh frozen lower limbs (n = 10) were used for anatomical dissections to assess pertinent and clinically relevant findings. Data relating to MSAP flaps was collected from a prospectively maintained database over a 2-year period. Both clinical data and modified Enneking scores were analysed.

RESULTS

Anatomical study: A mean of 2.1 ± 0.99 perforators arose from the medial sural artery, located 11.9 cm ± 2.07 along the line between the popliteal fossa and medial malleolus. The largest perforator was located 13.58 cm ± 2.01 from the popliteal artery. The distance from the dominant perforator to the first branching point within the gastrocnemius was 7.39 ± 1.50 (range 5-9.2 cm). The short saphenous vein was located on average 3.08 cm ± 0.77 from the dominant perforator. Clinical study: Twenty free and nine pedicled MSAPs were included (n = 29). Open lower limb fractures (n = 18, 62%) and infection (n = 10, 35%) were the most common aetiologies. Defects sites included: foot-and-ankle (n = 12, 55%), knee (n = 9, 31%) and anterior leg (n = 4, 14%). Four patients (14%) required SSG to for donor site coverage. Venous congestion was responsible for partial flap necrosis in 6.9%(n = 2) of patients. All wounds were healed at discharge. At 14 months, the mean Enneking score was 72.5%. All patients were ambulant, 96% returned to work and 87% were using pre-operative footwear.

CONCLUSIONS

The MSAP provides robust foot-and-ankle reconstruction, whilst permitting glide when over the knee. Patient satisfaction and functional outcomes are excellent with careful patient selection. Care should be taken to avoid compression or kinking of the large, thin walled veins as the most commonly observed complication was venous congestion. We advocate MSAP as a first choice flap for small-to-moderate foot, ankle or knee defects.

A Unifying Algorithm in Microvascular Reconstruction of Oral Cavity Defects Using the Trilaminar Concept

Although many algorithms exist to classify oral cavity defects, they are limited by either considering a single subsite or failing to provide a concise reconstructive algorithm for the breadth of defects. Based upon our experience as a tertiary referral center, a unifying algorithm is presented that guides free flap selection in this heterogenous population.

[The sural medial perforator flap: Anatomical bases, surgical technique and indications in head and neck reconstruction]

INTRODUCTION

The medial sural artery perforator (MSAP) flap is defined as a thin cutaneo-adipose perforator flap harvested on the medial aspect of the leg. The aims of this study were to describe the anatomical basis as well as the surgical technique and discuss the indications in head and neck reconstructive surgery.

MATERIAL AND METHODS

We harvested 10 MSAP flap on 5 fresh cadavers. For each case, the number and the location of the perforators were recorded. For each flap, the length of pedicle, the diameter of source vessels and the thickness of the flap were studied. Finally, we performed a clinical application of a MSAP flap.

RESULTS

A total of 23 perforators with a diameter superior than 1mm were dissected on 10 legs. The medial sural artery provided between 1 and 4 musculocutaneous perforators. Perforators were located in average at 10.3cm±2cm from the popliteal fossa and at 3.6cm±1cm from the median line of the calf. The mean pedicle length was 12.1cm±2.5cm. At its origin, the source artery diameter was 1.8mm±0.25mm and source veins diameters were 2.45mm±0.9mm in average. There was no complication in our clinical application.

DISCUSSION

This study confirms the reliability of previous anatomical descriptions of the medial sural artery perforator flap. This flap was reported as thin and particularly adapted for oral cavity reconstruction and for facial or limb resurfacing. Sequelae might be reduced as compared to those of the radial forearm flap with comparable results.