Introduction

Flap reconstruction surgery is an intricate procedure used in the restoration of form and function to body parts damaged by trauma, cancer, congenital deformities, or any major tissue loss. These flaps have shown useful in the reconstruction of numerous head, neck, thorax, and perineum abnormalities.

For reconstruction applications of head, neck, and trunk the myofascial flap of latissimus dorsi (LD flap) is an effective procedure [1]. It was first described by Italian surgeon Ignicio Tansini over 100 years ago as a technique for covering huge defects after breast surgery [2]. Subsequently, the flap procedure was modernized and revised for breast reconstruction in the 1970s, it has grown in popularity and persists as the mainstay of reconstructive plastic surgery today [3]. For many years there have been debates about the effect on shoulder function after LD flap breast reconstruction, and several reports have analyzed the impact of LD harvesting over the past fifty years [4]. To accurately assess the advantages and disadvantages of LD breast reconstruction, aspects other than donor site morbidity need to be clarified, such as duration of hospital stay after surgery, complication rate, aesthetics of the result, and probable need for flap repair [5].

Pickrell first described the pectoralis major myocutaneous flap (PMMF) in 1947, and Ariyan improved it in 1979 for use in head and neck deformities [6]. PMMF is a flap used in head and neck reconstruction because of its simplicity while harvesting, large soft tissue volume, huge skin blade, adaptability, consistency, and brief operative time. However, due to the enhancement of microvascular procedures and the widespread use of slow tissue transfers, the disadvantages of PMMF have increased and its popularity has declined. Disadvantages include excessive bulk, chest wall deformities, impaired neck and shoulder function, high complication rate, and partial gangrene of the skin paddle [7]. In developing nations where medical resources are inadequate PMMF is widely used while it is less commonly used in Western countries where microsurgical procedures are more readily available [8]. The function of PMMF in head and neck reconstruction appears to have changed from a «work lobe» to a «rescue lobe» in the era of free lobes [9]. PMMF is an essential tool for the reconstruction of head and neck defects, as it can be applied as an emergency flap in the event of flap insufficiency or complications, as well as to protect the main vessels of the neck. Modifications to the flap harvesting technique ensure its reliability and reduce the impact on the donor site’s function [10].

Abdominoperineal resection (APR) has been a problem since its introduction in 1908 [11]. The use of cylindrical extra elevator excisions has resulted in enormous perineal defects and pelvic dead space, leading to morbidity. Newer strategies such as myocutaneous or myofascial flaps have been developed to address these issues. The rectus abdominis (RAM) myocutaneous flap, which was initially described by Mathes and Bostwick in 1977, has been used to reconstruct surgical defects at various sites [12—15]. Shkula and Hughes in 1984 initially described its usefulness to fill complex perineal defects and later it was popularized by Tobin and Day [16]. The RAM flap due to its strength, ease, and adaptability is now commonly used by reconstructive surgeons in the UK. So, the aim of this review is to assess the advantages and disadvantages of three significant upper trunk myocutaneous flaps: the latissimus dorsi, pectoralis major, and rectus abdominis for various reconstructive surgeries.

Materials and Methods

Major medical databases were searched like Pubmed, BMJ Journals, Scopus, Wiley, Elsevier, and Science Direct to identify all studies investigating all trunk muscles and their use in flap reconstruction. Extracted data consisted of the anatomy and physiology of muscles, indications, complications, and techniques of flap transfer and reconstruction. Keywords included to select the articles were latissimus dorsi, pectoralis major and rectus abdominis, and flap transfer. Around 53 articles, related to our review, were studied and scrutinized to create this review (Fig. 1).

Fig. 1. Showing how data was extracted.

Results

Anatomy and Physiology

Latissimus Dorsi (LD)

One of the biggest and powerful muscles in the body is the latissimus dorsi muscle [1]. It originates from the outer surface of the inferior third or fourth rib, the iliac crest, the spines of the inferior sixth or seventh thoracic, lumbar, and upper sacral vertebrae, and the inferior angle of the scapula. Muscle fibres go to the armpit and enter the intertubercular groove of the humerus in the form of a large tendon [17]. It lies superficially over the ribs and intercostal muscles running downwards and towards the lateral side of the scapulae. It receives blood from the thoracodorsal vessels and is supplied by the thoracodorsal nerve [18]. Its function is to medially adduct, lengthen, and rotate the humerus and fix the tip of the scapula to the dorsal aspect of the chest wall [19].

Pectoralis Major (PM)

The medial portion of the clavicle, the sternum, cartilage, and the abdominal external oblique muscle are the sources of the pectoralis major muscle. Its fibres pass transversely and converge towards its insertion on the humerus. The thoracoacromial artery’s pectoral branch and its veins serve as the foundation for the pectoralis major flap, an axial flap. The long thoracic artery and internal mammary artery provide additional blood supply. To maintain dependable perfusion, the skin island should be situated far towards the costal margin. The lateral pectoral nerve, which travels via the pectoralis minor muscle and transmits two to three branches to the pectoralis major, innervates this muscle. Depending on the functional and aesthetic goals of the flap, the denervated muscle loses mass over time [20].

Rectus Abdominis (RAM)

The deep inferior epigastric artery (DIEA), originating from the external iliac artery, supplies blood to free Traverse rectus abdominal muscle (TRAM) flaps. The internal thoracic artery continues into the superior epigastric artery, which anastomoses with the DIEA, making the flap a Mathes and Nahai type III muscle flap [21]. The deeper portion of the rectus abdominis muscles is supplied by the epigastric arteries. The Type II vascular pattern is most frequently produced when the DIEA splits at the arcuate line, forming a medial and lateral line of perforating vessels. Sometimes, a single (Type I) or trifurcating (Type III) DIEA can also be seen [22, 23]. All muscular and fasciocutaneous perforators in a TRAM flap are left in the flap during harvesting. Muscle-sparing (MS) 0 to 3 denotes different variants of muscle harvest, with MS1 divided into medial and lateral segments. In MS2 flaps the surgeons remove a thin strip of tissue from the centre of the muscle, leaving the lateral and medial muscle segments intact. MS3 is a deep inferior epigastric perforator flap with complete muscle preservation [24]. TRAM flap blood supply zones to the skin underneath were labelled by Hartrampf, as Zone I includes the area directly above the rectus muscle while Zones III and IV are the flap’s ipsilateral and contralateral lateral skin, and Zone II is across the midline [25]. Contralateral abdominal skin is not supplied by the deep inferior epigastric artery and is often removed for free flaps. Zones I and III are considered additional trustworthy skin islands [26]. Ninkovic and Holm changed the classification of Zone I exactly on the muscle and Zone II next to the lateral zone, as it resembles the architecture of the free flap.

Indications of LD, PM, and RAM in flap reconstruction

Indications of using trunk muscles in flap reconstruction are shown in Fig. 2.

Fig. 2. Showing indication of using LD, PM, RAM in flap reconstructions.

LD flap is a well-established surgical procedure frequently used for instant breast reconstruction as well as defect coverage in locally advanced breast cancer [27]. It can also be used for full scalp defects, facial transformation, breast radiation, and transgender surgery to produce a neophallus [28—32]. In unusual incidents, a «mega flap» which involves the latissimus dorsi and soft tissues around the scapula can be removed, requiring the removal of the subscapular artery [33]. Patients must not undergo reconstructive surgical procedure until they are medically fit and get clearance from the cardiovascular unit because the operative time may be longer and there can be substantial blood loss, specifically during free tissue transfer [34]. If patients require radiation therapy, the muscle flap covering split-thickness skin grafts must not be displaced, as skin grafts necessitate a healing time of at least six weeks before irradiation [35]. Reverse latissimus dorsi (RLD) flap can be used to reconstruct lower back defect. To extend the flap caudally the surgeons can dissect the perforators of the intercostal artery and veins (PICAV) and freed them from the intercostal space. This enabled the flap to extend caudally while maintaining its blood supply [36].

PMMF are a frequently used reconstructive modality to restore head and neck defects [37]. Other indications which require flap reconstructions include soft tissue defects of the oral cavity, hypopharynx, oropharynx, scalp and neck, carotid coverage, after radical neck dissection before radiotherapy, covering the skull base, a substitute to free flaps in the event of failure of the free flap or unavailability of a free flap reconstruction [38].

The most frequent need for reconstruction is due to acquired breast abnormalities after breast cancer therapy. However, patients with Breast cancer gene (BRCA1/2) or other genetic susceptibility are also frequently treated with a bilateral mastectomy and reconstruction [39]. The TRAM flap can be utilised for further types of chest reconstruction following the removal of tumours or congenital issues like Poland’s syndrome. When a significant tongue defect needs to be repaired and more bulk is required which the forearm flap can’t provide, this flap may be helpful. As a last example, consider the restoration of skull base defects, where a sizable volume of conformable, vascularized muscle is needed to fill up a skull base defect and support a dural closure [39]. PM and RAM sheath flap can be very beneficial in the reconstruction of deep sternal wound infection after cardiac surgery, even in older patients [40].

Technique of using LD, PM, and RAM in flap reconstruction

Latissimus dorsi (LD)

Effective planning and implementation of the latissimus dorsi flap procedure necessitates cautious consideration of numerous techniques to warrant ideal results in reconstructive surgery [1].

Standard procedure of harvesting the latissimus dorsi flap in a patient is commonly done in a prone position and transitioning to a supine position for flap inset, alternative positions can also be efficient. Some surgeons choose a lateral decubitus or supine position with a padded bump or surgical assistant to maintain a slightly rotated positioning. These alterations provide flexibility and may suit specific patient requirements or surgeon preferences [1].

Accurate measurements guarantee sufficient tissue coverage and ideal consequences when planning a pedicled flap. An effective method that involves the marking of the distal end of the flap that needs to be harvested is to use a gauze strip. Based on the required length and position of the pedicle in free tissue transfer, the donor site of the dermal spoon is evaluated. The thoracodorsal artery enters the latissimus dorsi muscle about 10 cm posterior to the muscle insertion at the humeral head, and this entry site needs to be present in each flap to warrant tissue viability [1].

Monopolar electrocoagulation is used to lift the skin and subcutaneous tissue from the surface of the muscle, if a skin blade is not required, then a medial muscle incision is made. An alternate technique is used to mark the position of the valve leaflet based on the estimated site of entry of the thoracodorsal vessels into the muscle. The skin blade is cut and dissected on the surface of the latissimus dorsi muscle and exposed by electrocoagulation from the side and top. The thoracodorsal nerve is then placed parallel and lateral to the vessels with microsutures over the masseteric nerve [1].

The thoracodorsal vessels can be cut proximally to lengthen the pedicle, for free tissue transfer, it also requires ligation of the serratus anterior and scapular ramus. Once a satisfactory pedicle segment has been prepared, the flap can be ligated and repositioned for the microvascular anastomosis. In pedicle flap transfers of the head and neck, it is principally significant to detach the humerus insertion of the latissimus and fix the vascular branches to the scapula to allow better rotation The pedicled flap can be transferred by creating a subcutaneous plane on the surface of the pectoral muscle, similar to the tunnel on the surface of the collarbone, and an intermediate incision. The tissue tunnel must be large enough to lodge the flap easily without compressing the vessels [1].

After flap transferral, the wider ridge may be created with layers of absorbable and non-absorbable sutures. Thorough haemostasis at the puncture and harvesting spot is mandatory to avoid hematoma development. If a bare muscle flap is transferred, it must be enclosed with split-thickness skin grafts and a pillow. Substantial subcutaneous undermining may be required for improvement and closure of the donor skin, especially with huge skin paddle transfers. [1].

Pectoralis major (PM)

Initially the clavicle, xiphoid process, and ipsilateral border of the sternum are identified, then the extent and site of the skin paddle is marked, and a vascular axis is traced on the skin of the breast. First an incision is given laterally in front of the pectoralis major muscle, later an inferior, medial, and lateral incisions are given through the skin, subcutaneous fat, and chest fascia to the chest wall. The upper incision leads to the muscle fibres and the skin island is pressed against the muscle using absorbable sutures. The pectoralis major receives blood via the pectoral branches of the acromial thoracic artery and the lateral thoracic artery. When cutting the muscle fibres along the base of the sternum, care must be taken to ensure that the internal pectoral perforators should not get damaged adjoining to the sternum that feeds the deltoid [41].

Once the flap has been severed from the chest wall, a subcutaneous channel is made between the neck (holding the perforators covering the deltoid flap) and the chest, and the flap is inserted under the sternum. In challenging incidents, such as patients with wide flaps, usage of sterile liquid petroleum jelly is recommended to lubricate the flap and elevation of the shoulder on the same side to enable passage. Also, the instillation of a vasodilator (papaverine or lidocaine) at the base of the flap is recommended while doing the procedure [42]. The myofascial flap may be elevated with no skin blade in female patients. To increase length, the skin lamina can be extended beyond the lower border of the muscle belly, or the clavicle part of the pectoralis major muscle may be severed over the epiphysis. Additional option is to remove the middle third of the collarbone. The deltoid flap must be removed from its distal portion, till the medial portion of the thoracoacromial artery. Both the deltoid flap and the large thoracic flap can be used on the identical side. The lateral thoracic artery must be saved while separating the humeral head of the pectoralis major and the lateral border of the pectoralis minor [43].

Rectus Abdominis (RAM)

A RAM flap based on the deep inferior epigastric artery and vein was used.

A skin paddle was cut from the umbilicus to the costal margin, the width being determined by the dimensions of the perineal defect and the mobility of the abdominal wall. The subcutaneous fat must be removed till the anterior rectus sheath, exposing the entire rectus muscle. The muscle was severed by coagulation several centimetres above the skin and fascial paddle. The flap was elevated from the rectus sheath and the inferior epigastric artery and vein were identified at the level of the arcuate line. The attachment of the rectus muscle to the pubic symphysis was retained to provide additional support to the inferior epigastric vessel and avoid torsion.

A suprapubic cut was created in the peritoneum to construct a trough for the flap, and the flap was turned in a 270° forward roll to access the pelvic floor. Only the medial portion of the sheath is used in the modified flap harvesting technique, leaving the lateral 50%. The muscle attachment from the symphysis pubis may be separated to add length if the flap cannot reach the perineum. However, this could make the flap flimsier. For big flaws, a transverse or oblique RAM flap that directly matches the form and dimensions of the defect can be used to take a larger flap [44].

The abdominal wall was closed with nylon sutures involving the anterior and posterior rectus sheaths from which the rectus muscle had been removed. If the flap was extremely big, a fascial defect can develop in the rectus sheath at the place of the flap elevation. Care should be undertaken to tie the posterior peritoneal layer beneath the arcuate line to avoid disrupting the flap. In cases where the patient was operated on, the use of another rectus muscle to design the flap was preferred. If this was not practical, a radiologist would review the preoperative contrast-enhanced CT scan and confirm patency of the corresponding inferior epigastric vessel before utilizing that side for the flap [44].

Complications of using LD, PM, and RAM

Vascular damage can cause partial or complete flap damage within the first few weeks of healing [34]. Due to inadequate supply of blood necrosis of the distal end of a pedicled flap can occur, and major flap damage can result from vessel collapse due to lack of ligation of the ramus to the scapula or patient repositioning. Flaps can be saved if vascular disease is identified and corrected soon. However, entire flap loss can happen if there is delayed intervals of venous congestion or insufficient arterial supply. Intraoperative haemostasis must be precise and patient movements must be restricted during the initial two weeks after the surgical procedure to avoid hematoma formation [1].

After LD breast reconstruction shoulder functioning can be easily assessed by change in range of motion (ROM) which is an accepted and easy method to evaluate the procedure. It is usually assessed with a goniometer, but now a days digital evaluation techniques have been developed [45]. ROM should be performed before and after the surgical procedure, and with a follow-up that recognizes the physiological modifications and progress of scar-tissue after the surgical procedure. Numerous researchers have investigated the variations in ROM after LD transfer, but just three papers have described definite changes after breast reconstruction with the pedicled LD flap. So, the conclusion remains unclear [5].

Isokinetic dynamometry is the gold standard for testing muscle [46]. Studies have shown that after LD breast reconstruction some grade of weakness in shoulder movements will happen, but the agonistic muscles of the shoulder will try to balance this deficit [5].

The Disability Arm, Shoulder, and Hand (DASH) survey was developed by the American Academy of Orthopaedic Surgeons and has been used to assess shoulder function following LD breast reconstruction with conflicting findings [47]. Prospective research found no statistical or clinical differences prior to surgery and 1 or 3 years after surgery, while retrospective studies got average DASH scores of 7.2 and 16.0 [48]. The most common complication which can happen after LD flap transfer for breast reconstruction can be seroma [27].

Postoperative complications were roughly divided into flap-related and non-flap-related complications. For analysis of postoperative flap loss, flap loss was classified as entire or partial flap loss. Partial flap loss was further divided into major or minor partial flap loss. A major partial defect was stated as a full-thickness partial defect that prolonged hospitalization or required surgery. Minor flap loss was defined as partial loss of thickness without significantly delaying hospital clearance or warranting surgery. Complications related to flap include total flap necrosis, major partial flap ischaemia, minor partial flap ischaemia, fistula, wound dehiscence, hematoma, and infection. Complications that are not related to flap include pleural empyema, chyle leak, and parotid fistula [49].

A significant issue that required returning to the operating theatre and muscle branch diathermy was postoperative flap haemorrhage. Rates of abdominal problems after RAM flap elevation range from 0% to 11% [50, 51]. 31% of patients had perineal wounds that required resuturing while under local anaesthesia due to superficial wound dehiscence. 25% of the patients experienced mild perineal cellulitis, which was managed with antibiotics. 6% of patients experienced flap failure that necessitated excision and may have put strain or twisting on the vascular pedicle. During the early postoperative period, there was bleeding noted from the flap in 6% of patients, necessitating a blood transfusion, a second visit to the operation room, and diathermy of the problematic muscle fibers. Following cancer surgery, 33% of patients experienced illness recurrence [50].

Hernias at the donor site were observed in some patients, while none were visible in the latter. The donor locations received technological improvements and Prolene mesh assistance. In 87% of patients, the perineal wound completely healed. A 3% urinary fistula through the perineal incision, a 3% abdominal wall abscess, a 3% septic shock connected to pneumonia, and one idiopathic septic shock were among the inpatient sequelae [51].

In non-irradiated patients or those with minor flaws, the perineum can be healed, however extralevator dissections in post-irradiated patients make wound closure and healing more difficult. APRs can become complicated by non-healing wounds in as many as 51% of patients, with a significant wound complication incidence of 35% out of 160 individuals [52, 53].

Advantages of using LD, PM and RAM

LDF advantages include least donor site morbidity, comparatively speedy healing, and excellent aesthetical result when it is used for breast reconstruction [54]. Now a days 2 types of LD flap can be used: Thoracodorsal artery perforator flap with capillary perforators (TAPcp) flap and low-skin-paddle pedicled LDMF which preserved most of the LD muscle at the time of flap harvesting; these two types of flaps are classified as «muscle sparing latissimus dorsi flap (MSLDF)». This reduces donor site morbidity and preserves the function of the donor area to the greatest extent and result in a faster postoperative recovery as compared to traditional LDMF [55].

PMMF is a workhorse flap in head and neck reconstruction. Its strong pedicled supply from the pectoral branch of the thoracoacromial trunk and its closeness to the neck makes it a perfect choice for managing head and neck cancers which are within its reach for reconstruction. It can also be safely utilized for reconstruction in seriously ill and aged patients with comorbidities. PMMF with deltopectoral flap modification can provides a faster and a reliable alternate as compared to free flap reconstruction as it provides a tension and complication free, solution to the closure of the skin defect following the harvest and position of a pectoralis major flap [56].

RAM flap has a reliable blood supply, large bulk can be harvested, and it gives a good cosmetic and functional outcome, so it is favoured by most reconstructive surgeons [57].

Conclusion

From the review, we can conclude that the latissimus dorsi, pectoralis major, and rectus abdominis flap are beneficial flaps in the reconstructive surgeon’s arsenal.

Implanted LDMF is a reliable and safe breast reconstruction procedure in case of breast cancer recurrence after previous radiotherapy and is associated with a decreased proportion of serious complications, resulting in steady and comfortable outcomes without substantial impairment of upper extremity function.

The usage of PMMC flaps in oral reconstructive surgery is a safe, rapid, one-step procedure that does not require expertise in microvessels and is particularly indicated in elderly patients and patients with severe comorbidities. The PMMC flap is an adaptable flap with an exceptional access to face, oral cavity and neck area. Besides limited proficiency and assets, it is still a workhorse flap in head and neck reconstruction.

The RAM flap is a strong option for rebuilding the perineum following extralevator abdominoperineal excision (APR), with a great success rate and a low morbidity rate. It is beneficial for flap reconstruction in complicated perineal wounds.