The Chimera Flap: A Quarter Century Odyssey

Advances in Microvascular Reconstruction of the Orbit and Beyond: Considerations and a Checklist for Decision-Making

This paper aims to discuss the microvascular reconstruction of the orbit and adjacent regions and to propose a checklist to aid the reconstructive surgeon in this challenging undertaking. The discussion is based on a literature review that includes 32 retrospective case series, 5 case reports published in the last 34 years in PubMed, and 3 textbook chapters. Additionally, it relies on the senior author's expertise, described in a case series, and two case reports published elsewhere. Classifications and treatment algorithms on microvascular orbit reconstruction generally disregard patient-related factors. A more holistic approach can be advantageous: patient-related factors, such as age, comorbidities, prognosis, previous interventions, radiotherapy, and the wish for maximal dental rehabilitation and a prosthetic eye, have the same importance as defect-related considerations and can inform the choice of a reconstructive option. In this manuscript, we examine defect- and patient-related factors and new technologies, provide a checklist, and examine future directions. The checklist is intended as a tool to aid in the decision-making process when reconstructing the orbital region with microvascular flaps.

ALT in combination with triple-rolled TFL for reconstruction of a complex tendoachilles defect: technical details and rehabilitation regime

A fit man in his 60s presented with an infected Achilles tendon (AT) following two failed repairs for a traumatic rupture. Initial debridement of necrotic tissue resulted in a large soft tissue defect requiring robust coverage. Following aggressive wound management, an anterolateral thigh flap was elevated with tensor fasciae latae (TFL) which was triple-rolled to provide soft tissue coverage and tendon reconstruction.The flap remained healthy and was monitored with a flow coupler device. Initially, the foot was placed in plantarflexion before gradually increasing the angle to neutral and a thermoplastic splint was used to offload pressure on the flap. Following 1 month of non-weight-bearing, gentle mobilisation began. Three months postoperatively, the patient could walk, had resumed indoor cycling and demonstrated a comparable heel raise with the contralateral side. MRI showed a taut TFL attached to the distal AT and ultrasound showed a smoothly gliding TFL.

Complex reconstruction of the clavicle with a prefabricated medial femur condyle chimeric flap including a superficial circumflex iliac artery perforator flap: A case report

The medial femur condyle (MFC) cortico-periosteal flap is a popular flap for bone reconstruction. The use of a chimeric version of this flap with a skin island has been described, but anatomical arterial variation can occur that prevent its harvest. Furthermore, the donor area of the skin paddle has been debated as poor because of the scarring in a visible area and because of the difficulty in obtaining pliable thin skin. We present a fabricated chimeric MFC cortico-periosteal flap joined with a superficial inferior epigastric perforator (SCIP) flap to reconstruct and augment a sclerotic and insufficient small clavicula with the skin paddle acting as a monitor and as a substitute for the overlying skin. A 52-year-old female patient had a history of multiple refractures of the right hypoplastic clavicle with a diameter of 7 mm, resulting in a sclerotic bone with a fibrotic scar. The reconstruction was done in one surgical session using a cortico-periosteal flap from the left medial condyle and a thin SCIP flap from the left groin. The area of the clavicle to be reconstructed was 3 cm, and the direct overlying skin (approximately 6 × 3 cm) was severely scarred and painful. The MFC flap was 5 × 4 cm, while the SCIP flap was 7 × 3.5 cm. The SCIP flap artery was anastomosed on the table end-to-side to the descending genicular (DG) artery of the MFC, and the vein was anastomosed end-to-end to a comitans vein of the DG artery. The flap fully survived after an initial congestion. At 12 months, we observed a satisfactory reconstruction of the clavicle with an enhanced diameter of 12 mm. The patient recovered full function of the shoulder with no pain. Using a fabricated chimeric flap composed of a medial femoral condyle and a superficial circumflex artery perforator flap may be an additional option for tailored reconstruction of complex osteo-cutaneous defect of clavicle.

Variations in deep iliac circumflex artery perforator chimeric flap design for single-stage customized-reconstruction of composite bone and soft-tissue defect

BACKGROUND

The deep iliac circumflex artery (DICA) perforator (DICAP) chimeric flap is a valuable treatment strategy for single-stage reconstruction of composite bone and soft-tissue defects in upper and lower extremities. However, its utilization rate remains low owing to anatomical variations that lead to challenges when identifying and dissecting perforators.

METHODS

A comprehensive anatomical investigation was conducted on the DICA system by injecting lead oxide into 12 fresh cadavers following a standardized procedure. From January 2008 to December 2020, 30 patients with composite bone and soft-tissue defects received reconstruction surgery with DICAP chimeric flap. One of the four specified surgical techniques was used to create a modified DICAP chimeric flap for the patients based on the size, shape, and location of the defect.

RESULTS

Two branching patterns of DICA, transverse and ascending branches, were observed, and the former gave off the osteomusculocutaneous perforators and terminal musculocutaneous perforators. Thirty DICAP chimeric flaps were elevated successfully. The size of the skin paddles measured from 9 × 4.5 cm to 22 × 9 cm, and the bone components ranged from 3 × 2.5 × 1.5 cm to 6 × 3.5 × 2 cm. All flaps survived successfully after the operation, and all patients achieved primary closure of the donor sites. No patient encountered the fracture of transferred iliac segments. The mean bone union time was 5.5 months (ranging from 4 to 8 months).

CONCLUSION

The DICA system is a suitable source for harvesting the DICAP chimeric flap to reconstruct composite bone and soft-tissue defects. It provides a flexible design for individualized coverage of such defects with limited donor-site morbidity.

Individualized design of thoracodorsal artery perforator chimeric flap for customized reconstruction of complex three-dimensional defects in the extremities

BACKGROUND

It was always challenging to accurately and effectively reconstruct the complicated defects with three-dimensional tissue deficits in the extremities. Muscle-chimeric perforator flap is an excellent choice for repairing those complicated wound. However, problems like donor-site morbidity and time-consuming intramuscular dissection still exist. This purpose of this study was to present a novel design of the thoracodorsal artery perforator (TDAP) chimeric flap for the customized reconstruction of complex three-dimensional tissue defects in the extremities.

METHODS

From January 2012 to June 2020, 17 patients with complex three-dimensional deficits in the extremities were retrospectively analyzed. All patients in this series underwent extremity reconstruction using latissimus dorsi (LD)-chimeric TDAP flap. Three different types of LD-chimeric TDAP flaps were performed.

RESULTS

A total of seventeen TDAP chimeric flaps were successfully harvested for the reconstruction of those complex three-dimensional defects in extremities. Among them, Design Type A flaps were used in 6 cases, Design Type B flaps were performed in 7 cases, and Design Type C flaps were used in the remaining 4 cases. The sizes of the skin paddles ranged from 6 cm × 3 cm to 24 cm × 11 cm. Meanwhile, the sizes of the muscle segments ranged from 3 cm × 4 cm to 33 cm × 4 cm. All the flaps survived. Nevertheless, one case required re-exploration owing to venous congestion. Moreover, the primary closure of the donor site was successfully achieved in all patients, and the mean follow-up time was 15.8 months. Most of the cases displayed satisfactory contour.

CONCLUSION

The LD-chimeric TDAP flap is available for the reconstruction of complicated defects with three-dimensional tissue deficits in the extremities. It provided a flexible design for customized coverage of complex soft tissue defects with limited donor site morbidity.

Perforator and Perforator Flap Spinoffs: A Historical Journey

SUMMARY

The concept of the perforator has now become a fundamental topic well known in every training program. However, that has not always been so. The mere definition of the word has historically been argued relentlessly; nevertheless, its major derivative, the perforator flap, has become accepted as a basic consideration whenever flaps need be selected. However, this has not been the only spinoff derived from the author's investigations of the perforator, a point that should be stressed in addition to some reiterations of pertinent and perhaps confusing nomenclature that deserve to be reemphasized. Truly, it has been amazing to see how our ideas and innovations arise simultaneously and independently throughout the world of reconstructive surgery. A final plea is made to sustain the future-each of us must continue to contribute our passion and our knowledge to all others by means of that technology now globally so instantaneously available.

[An introduction into the use of fabricated chimeric flaps in replantation surgery of digits]

Since microsurgical finger replantations started to be successfully performed at the beginning of the 1960 s, there has been an evolution in the techniques for restoring blood flow to the amputated fingers. Initially, end-to-end anastomoses were performed. Later on, vascular grafts - predominantly vein interpositional grafts - were successfully used for difficult avulsion injuries. These vascular grafts were extended by microvascular flaps in the form of flow-through flaps in cases with simultaneous soft tissue loss. A further development of these techniques has been achieved by the replantation of amputated fingers with the help of fabricated chimeric flaps. The amputated finger is anastomosed microsurgically with a flap "in tabula" before the actual replantation. Only then is the fabricated chimera replanted as a construct. The latest development so far is heterotopic replantation with secondary replantation in the form a fabricated chimeric flap. By way of introduction, we describe three cases in which we have successfully applied this concept of fabricated chimeric flap surgery for orthotopic thumb replantations.

Versatile design of compound vastus lateralis muscle and anterolateral thigh musculocutaneous perforator free flaps for customized reconstruction of complex skin and soft tissue defects in the extremities

BACKGROUND

Compound anterolateral thigh flaps are popular for three-dimensional reconstruction of complex soft tissue defects. We present our 10-year experience using compound vastus lateralis (VL) muscle and anterolateral thigh musculocutaneous perforator (ALTP) flaps, and introduce three versatile customizations of this flap for individualized reconstruction of complex three-dimensional soft tissue defects.

METHODS

From May 2008 to June 2017, compound VL muscle and ALTP flaps were performed in 67 consecutive patients aged 14-75 years (62 men and 5 women). The defects were in either the lower (n = 53) or upper extremity (n = 14), and ranged in size from 8 × 4 cm2 to 25 × 6 cm2. Dead space volume ranged from 4 × 2 × 1 cm3 to 20 × 3 × 2 cm3, and all flaps were harvested from patients' thighs as one of three types. In type A, a single perforator supplied both the skin and muscle components, with the vascular bundle penetrating the muscle component. In type B, a single perforator supplied both skin and muscle components with separate branches to the skin and muscle. In type C, separate vessels supplied the skin and muscle.

RESULTS

In the 67 patients, 65 flaps survived, and the donor site was closed directly. Vascular compromise occurred in four patients on the first postoperative day. Two flaps were salvaged after emergency re-exploration. Flap loss occurred in two patients, and these defects were repaired using other flaps. The follow-up period ranged from 8 to 60 months (mean, 11.9 months). All flaps had satisfactory appearance and texture, and no patients experienced limited hip and knee joint mobility from the donor site operation.

CONCLUSIONS

Compound VL muscle and ALTP flaps are a reliable option to reconstruct complex defects of the extremities. Identifying three flap types allowed for more precise customization to cover complex defects with limited donor site morbidity.

The Chimeric Propeller Flap

A chimeric flap consists of multiple discrete tissues or flaps connected only by a common source vessel. Each component must have an independent source of circulation. Rotation of any included part only about its specific vascular supply, such as done with a propeller flap, would be possible. These characteristics, whereby the chimeric flap concept and propeller flap concept are combined, would result in a chimeric propeller flap . Such a choice will enhance overall flap insetting capabilities and versatility, while often limiting the reconstructive need to but a single donor site!

Attributes of Perforator Flaps for Prophylatic Soft Tissue Augmentation Prior to Definitive Total Knee Arthroplasty

BACKGROUND

 As our population ages, the demand for total knee arthroplasty (TKA) will dramatically increase to ensure an independent lifestyle with unimpeded and pain-free ambulation. Complications will be inevitable, especially in that patient with preexisting soft tissue deficits or extensive scarring in the knee region. Under these circumstances, prophylactic soft tissue augmentation should be strongly considered and be extremely beneficial.

METHODS

 A retrospective review of all TKA procedures at our institutions over the past two decades revealed seven patients who specifically had soft tissue augmentation prior to their definitive TKA. Each had a single perforator flap used to achieve this. In no cases was a muscle flap used for this purpose. Excluded were all patients who had a flap of any kind for coverage of an exposed prosthesis or to accomplish wound healing after the TKA.

RESULTS

 Seven perforator flaps were utilized in seven patients for soft tissue replacement prior to the ultimate TKA. For smaller defects in three patients, a local island medial sural artery perforator flap was used. For larger defects in four patients, an anterolateral thigh perforator free flap was necessary. All flaps were successful. The only complication was an implant infection after one anterolateral thigh free flap that required a revision arthroplasty that eventually allowed salvage. Unrestricted ambulation was possible in all patients except for one who had a preexisting contralateral below-knee amputation.

CONCLUSION

 As the number of TKA procedures in the near future increases, prevention of the absolute number of complications becomes even more important. An awareness that any knee region suboptimal soft tissue base can lead to wound breakdown and then periprosthetic infection should alert all involved that prevention of this sequela can be best achieved by prior soft tissue augmentation. Preferably, this may be possible by capturing the assets of local and free perforator flaps.

The extended latissimus dorsi-serratus anterior chimeric local free flap for salvage of the complicated posterolateral thoractomy incision

BACKGROUND

Composite chest wall reconstruction, following the assurance of chest wall stability, often requires well-vascularized soft tissue coverage with flaps to insure adequate wound healing. Unfortunately, prior surgical approaches such as the posterolateral thoractomy incision or extensive wound breakdown may impede the availability of local or regional choices. A free flap would then be a reasonable option, but in the unstable patient a new donor site is unreasonable. Instead, the otherwise inadequate muscle remnants often transected by the usual thoracotomy incision can be extended by microvascular grafts to provide the necessary reach to the defect.

METHOD

The ipsilateral cephalic latissimus dorsi and/or serratus anterior muscle remnants following their transection by a posterolateral thoractomy incision can be simultaneously raised as a chimeric flap pedicled in common by the thoracodorsal vessels. The distance the pedicle must be extended to reach the defect requiring coverage is measured, and a vascular graft from the descending branch of the lateral circumflex femoral vessels of the same length is harvested. The thoracodorsal vessels are divided, the vascular graft inserted and anastomosed end-to-end to the cut ends of the former, and then the flap can be stretched the required distance for insetting.

RESULT

A case example of use of the ipsilateral latissimus dorsi-serratus anterior muscle remnants used after extension with arterial and venous grafts to the thoracodorsal vessels as the recipient site is presented with successful salvage of a life-threatening posteriolateral thoractomy wound dehiscence.

CONCLUSION

Transection of muscles from a posterolateral thoracotomy incision does not preclude their use as flaps in extenuating circumstances. Their pedicle can be extended using vascular grafts and microvascular techniques in a sense to create a local free flap to provide another solution to a challenging problem.

Internally Fabricated Chimera Anterolateral Thigh-Amputate Flaps for Metachronous Reconstruction

The chimera flap is a versatile and exciting tissue composition for the reconstruction of complex tissue defects.

Supermicrosurgery: History, Applications, Training and the Future

Supermicrosurgery, a technique of dissection and anastomosis of small vessels ranging from 0.3 to 0.8 mm, has revolutionized the fields of lymphedema treatment and soft tissue reconstruction. The technique offers several distinct benefits to microsurgeons, including the ability to manipulate small vessels that were previously inaccessible, and to minimize donor-site morbidity by dissecting short pedicles in a suprafascial plane. Thus, supermicrosurgery has become increasingly popular in recent years, and its applications have greatly expanded since it was first introduced 20 years ago. While supermicrosurgery was originally developed for procedures involving salvage of the digit tip, the technique is now routinely used in a wide variety of microsurgical cases, including lymphovenous anastomoses, vascularized lymph node transfers and perforator-to-perforator anastomoses. With continued experimentation, standardization of supermicrosurgical training, and high quality studies focusing on the outcomes of these novel procedures, supermicrosurgery can become a routine and valuable component of every microsurgeon's practice.