9. Reconstruction

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© Springer Nature Switzerland AG 2021

R. Reti, D. Findlay (eds.)Oral Board Review for Oral and Maxillofacial Surgerydoi.org/10.1007/978-3-030-48880-2_9

9. Reconstruction

Ryan J. Smart1  , Beomjune B. Kim2, Robert Reti3, Neel Patel4, Ashish A. Patel5, Brett A. Miles6, Daniel Kwon6, Robert J. Chouake6, Todd R. Wentland7, Fayette Williams8, Daniel Hammer9, Roderick Y. Kim7 and James R. Martin10
(1)

University Medical Center/El Paso Children’s Hospital, Department of Oral Surgery, El Paso, TX, USA
(2)

Cancer Treatment Centers of America, Head and Neck Surgery, Tulsa, OK, USA
(3)

Southwest Oral Surgery, St. Louis, MO, USA
(4)

University of Miami/Jackson Memorial Health, Department of Surgery, Division of Oral and Maxillofacial Surgery, Section of Head and Neck Oncology/Microvascular Reconstructive Surgery, Miami, FL, USA
(5)

The Head and Neck Institute, Head and Neck Surgical Associates, Portland, OR, USA
(6)

The Mount Sinai Hospital, Department of Otolaryngology Head and Neck Surgery, Icahn School of Medicine at Mount Sinai, New York, NY, USA
(7)

John Peter Smith Health Network, Oral and Maxillofacial Surgery, Division of Maxillofacial Oncology & Reconstructive Surgery, Fort Worth, TX, USA
(8)

Division of Maxillofacial Oncology and Reconstructive Surgery, John Peter Smith Hospital, Oral and Maxillofacial Surgery, Fort Worth, TX, USA
(9)

John Peter Smith Hospital, Oral and Maxillofacial Surgery, Fort Worth, TX, USA
(10)

Mercy Hospital St. Louis, Otolaryngology-Head and Neck Surgery, Pratt Cancer Center, St. Louis, MO, USA
 
Keywords

OsteoinductionOsteoconductionOsteogenesisTibial graftIliac crest graftMeralgia parestheticaTracheostomyPectoralis flapFree tissue transferFibula free flapRadial forearm free flap3 vessel runoffPeroneal arteryBrown classificationRadical neck dissectionNeomandibleFlap monitoringAnastomosisAbbe flapGillies fan flapTongue flapFacial artery myomucosal (FAMM) flap

Cancellous Cellular Marrow Grafts and Corticocancellous Block Grafting

Terms:
  • Osteoconduction – graft material acts as a scaffold for vascular tissue and mesenchymal cells.

  • Osteoinduction – stimulation of osteoprogenitor cells to differentiate into new bone forming cells (osteoblasts).

  • Osteogenesis – transfer of vital osteoblasts to contribute to the growth of new bone.

  • Allograft – derived from the same species. Can provide osteoconduction and osteoinduction.

  • Autograft – graft obtained from the same individual. Provides osteoconduction, osteoinduction, and osteogenesis (See Table 9.1).

  • Xenograft – graft from a species that is non-human. Provides osteoconduction.

  • Alloplastic graft – graft from synthetic materials.

  • Creeping substitution – process by which osteoclastic activity creates new vascular channels, with osteoblastic bone formation, resulting in new haversian systems and osteogenesis from the graft.

Table 9.1

Autogenous bone graft sites

Harvest site

Bone available

Calvarium

No cancellous bone. Use as cortical onlay or bone mill for particulate graft.

Anterior ilium

Up to 50 mL, corticocancellous block also available.

Posterior ilium

Up to 120 mL, corticocancellous block also available.

Tibia

Up to 25 mL cancellous bone available. 1 × 2 cm cortical block.

Symphysis

Corticocancellous block up to 2 × 6 cm, 5 mL if milled for a particulate graft.

Maxillary tuberosity

Very small amount of cancellous bone for socket grafting or peri-implant or periodontal defects.

Ramus

Corticocancellous block of 2 × 5 cm.

Rib

Non-cancellous. Use as a costochondral graft or strut.

Tibial Bone Graft

  • Ease of access makes this a suitable procedure to be done in the outpatient surgery center or office.

  • Contraindications to harvesting bone from the proximal tibia include patients with history of surgery in the area or implanted hardware, acute infection of the soft tissues over the surgical site.

  • Relative contraindications would include patients with a history of metabolic bone disease.

  • Up to approximately 25 mL of cancellous bone (Table 9.1) can predictably be harvested from the proximal tibia, which makes this donor site good for many maxillofacial indications including alveolar cleft grafting, sinus elevation, and socket grafting.

Anatomy and Surgical Technique

There are two approaches that have been described for harvesting bone from the proximal tibia.

  1. 1.

    Medial approach.

     
  2. 2.
    Lateral approach that centers over the lateral tibial plateau, also known as Gerdy’s tubercle; most common approach. In this review, we will discuss the lateral approach.

    • To minimize difficulty with dissection and postoperative pain, it is important to avoid the tibialis anterior muscle, which attaches inferiorly to the harvest site when the incision is placed over Gerdy’s tubercle.

    • The attachments to this tubercle include the fascia lata above and the anterior tibialis muscle below. Together, these form the iliotibial tract that stabilizes the knee and hip during gait. Therefore, minimal stripping of these structures during dissection will minimize pain during ambulation post-operatively.

    • There are no major blood vessels or nerves located between the skin surface and periosteum of the bone over Gerdy’s tubercle; although, the lateral genicular artery does travel transversely above the tubercle and the anterior tibial artery travels along the anterior tibial surface below this tubercle.

    • The common peroneal nerve courses inferior to the tubercle and should not be found within the surgical site in a proper dissection.

     

Surgical Technique (Lateral Approach)

  • The patient is positioned with the knee partially flexed and medially rotated and prepared in a sterile fashion.

  • The skin and subcutaneous tissue should be infiltrated with epinephrine containing local anesthetic for bleeding and pain control.

  • 2 cm incision is marked directly over the palpable ridge of Gerdy’s tubercle. This incision is parallel to the tibial plateau (articulating surface) and oblique to the long axis of the tibia. An incision is made through the skin and subcutaneous tissue down to the periosteum.

  • Once the periosteum is incised, a small portion of the anterior tibialis muscle inferiorly and the fascia lata above will be stripped to allow access to the cortex.

  • A fissure bur, under copious irrigation, is used to make a 1.5–2.0 cm circular corticotomy. This can be removed with an osteotome and mallet or a periosteal elevator.

  • Curette is inserted, and in a rotational manner, the cancellous bone is harvested. The curette should be inserted transversely across the tibia in a downward direction. The risk of perforating the subchondral bone at the superior edge of the tibia and violating the knee joint is small; but proper care during curetting to avoid the area will minimize the chance of that complication.

  • Once the graft harvest is complete, the graft is placed into a 10 mL syringe and compacted. Tibial cancellous bone has a higher composition of fat compared to iliac cancellous grafts. It is important to extrude the extra fat cells and concentrate the progenitor cells.

  • This is stored on ice until ready for graft inset and the leg is closed. Bovine microfibrillar collagen (Avitene® ) or absorbable gelatin sponge (Gelfoam® ) can be placed into the harvest site for hemostasis.

  • The wound is then closed in layers and a dry sterile dressing is applied.

Complications and Management

  • Tibial bone graft complications include infection, gait disturbance, osteomyelitis, hematoma, seroma, fracture, and violation of the joint space.

  • Ecchymosis and Swelling of the Lower Leg and Ankle – more of a pseudo complication, can be decreased by keeping the limb elevated. Although normal weight bearing is permitted postoperatively, strenuous activities should be avoided, as this will increase pain and swelling. Resolves spontaneously.

  • Violation of the Joint Space or Fractures of the Tibia – treated with non-weight bearing therapy, splinting, and orthopedic surgery consultation.

  • Osteomyelitis  – MRI to evaluate for depth of invasion and true osteomyelitis. Consult orthopedic surgery. Infectious disease and wound therapy consult for possible hyperbaric oxygen and appropriate long-term antibiotic therapy.

Calvarial Bone Graft

  • Shown to have rapid revascularization and limited resorption that allows for resistance to remodeling and soft tissue displacement.

  • Limited morbidity and donor site deformity as well as donor site proximity to the recipient site makes calvarial bone useful in both craniofacial and dentoalveolar reconstruction.

  • The graft is mostly cortical, which makes it a durable graft for not only ridge augmentation but also orbital and craniofacial reconstruction.

Anatomic Considerations

  • Although there are several regions of the skull available for harvest, the most common is the parietal area. The skull is thickest in this area (average 6.3 mm) [1] and does not overlay dural sinuses or arteries.

  • There are no major nerves in the area. In most patients, the parietal scalp is fully hair bearing, which makes for acceptable scar camouflage.

  • Superior sagittal sinus runs 5 mm parasagittal to the midline. To avoid injury to the superior sagittal sinus, harvest should be 2 cm away from midline and 2 cm away from thin squamous portion of temporal bone inferiorly.

Surgical Technique

  • The parietal bone can be accessed by either a coronal incision with wide elevation of the scalp (which is convenient when upper facial skeletal exposure is needed in the case of trauma) or through a linear incision directly over the donor site.

  • After instilling the area with local anesthetic (with epinephrine), a scalpel is used to make an incision through the SCALP (skin, subcutaneous tissue, aponeurosis, loose areolar connective tissue, pericranium). The periosteum can be incised separately, although this is not necessary.

  • The loose connective tissue plane easily dissects (either blunt finger dissection or sharp dissection with the back of a scalpel blade) from the pericranium. This allows for separate incision through the pericranium. Separate elevation of the pericranium may lead to less blood loss, as this is less disruptive to cranial perforating vessels.

  • Raney clips (or a running suture) should be applied to the scalp edge instead of extensive electrocautery for hemostasis. Extensive electrocautery can damage the skin and hair follicles and increase the risk of alopecia over the incision.

  • Once the incision is made, a periosteal elevator can be used to elevate the scalp in a subpericranial plane until adequate bone is exposed for harvest.

  • A fissure bur under copious irrigation is used to outline the desired graft through the outer table. The bur can be used to bevel the outer margin of the corticotomy to facilitate placement of a curved osteotome to complete the outer table harvest.

  • With a curved osteotome, gentle malleting is done radially around the graft to separate the graft from the donor bed.

  • Once the graft harvest is complete, the graft is set aside in saline, and bleeding at the donor site is controlled. This is most commonly accomplished with bone wax. The resulting skull defect may be filled with hydroxyapatite cement or a titanium mesh to avoid a post-harvest deformity, although this is not always required.

  • The wound is then closed in layers. Care should be taken to approximate the galea (aponeurosis) as this will decrease scar width.

Complications

Complications associated with harvesting calvarial bone include the possibility of infection, alopecia, intracranial passage of instrumentation, dural tear, epidural hematoma, subgaleal hematoma, contour deformity, and scarring.

Perforation of Inner Cortex/Dural Tear

Craniotomy is frequently required to extend the visual field to identify underlying dural or parenchymal injury. If injury to cortex is identified neurosurgical consultation is required. Most tears can be treated with direct repair with a non-resorbable suture such as Nurolon™ (Ethicon). Larger defects may require grafting. Post-operative non-contrast head computed tomogram (CT) should be sought to rule out intraparenchymal hemorrhage.

Anterior Iliac Crest

  • Max of 50 cc of uncompressed cancellous bone (up to 5 cm defect) – remember 1 cm defect requires about 10 cc of bone graft.

  • Harvest site is located between Anterior Superior Iliac Spine (ASIS) and tubercle of ilium (which is 6 cm posterior to ASIS).

  • ASIS – attachment for external oblique muscles (medially), tensor fascia lata (TFL) laterally. Dissection laterally should be minimized as to prevent postoperative gait disturbance and pain. Inferior to anterior iliac crest are the gluteus medius and minimus muscles, which attach to the lateral cortex.

  • Iliacus muscle attaches to the medial surface of iliac crest (reflected during medial dissection)

  • Sensory cutaneous nerves (there are no motor nerves overlying the anterior ilium):

    • The most commonly encountered nerve is the lateral cutaneous branch of the iliohypogastric nerve (L1, L2) – this nerve courses over tubercle of the ilium. Damage to this nerve causes sensory disturbance over the lateral anterior third of the ilium.

    • Lateral cutaneous branch of subcostal nerve (T12, L1) courses over ASIS passing just inferior to iliohypogastric nerve.

    • Lateral femoral cutaneous nerve (L2–3) – most inferior of all three nerves of interest, courses medially between psoas major and iliacus, deep to the inguinal ligament, and perforates TFL to innervate lateral skin of thigh. In 2.5% of people, this nerve courses within 1 cm of ASIS placing it at risk during inferior dissection. Damage to this nerve can result in meralgia paresthetica (dysesthesia and anesthesia of lateral thigh) [2].

  • Perforators from deep circumflex iliac artery and vein originating from the external iliac system – located on the medial aspect of the ilium are the predominant vascular supply. The most common source of bleeding is from the superior gluteal artery (internal iliac system).

  • Left hip is most often chosen for donor site to prevent interference with driving.

Surgical Technique

  • Patient is placed in a supine position and a soft roll such as a saline bag or sandbag wrapped in a towel is placed to elevate the hip.

  • Retract skin medially with the surgeon’s nondominant hand, so that the resulting scar will end up lateral to the iliac crest and less likely to be irritated by clothing. The resulting scar is also more cosmetic.

  • Mark the incision site (4–6 cm in length and placed 1–2 cm anterior to tubercle of the ilium and 1 cm posterior to ASIS). Infiltrate the planned area of dissection with local anesthetic with epinephrine.

  • The incision is oblique along the anterior iliac crest – this will avoid the iliohypogastric and subcostal nerves which are superior and the lateral femoral cutaneous nerve which is inferior-medial.

  • Layers of the incision – skin, subcutaneous tissue, Scarpa’s fascia, and muscular aponeurosis.

  • Plane of dissection – between TFL (laterally) and external oblique and transverse abdominus muscles (medially) which is in an avascular plane. The dissection in this plane will lead straight to the iliac crest periosteum (sharply transected). The iliacus muscle is sharply dissected from the medial surface.

    • NOTE: This approach constitutes the medial approach.

      • Disadvantages of medial approach: higher incidence of meralgia paresthetica (lateral femoral cutaneous nerve) and postop ileus.

    • The lateral approach requires dissecting away the tissues lateral to the crest, which are the TFL and gluteus medius muscles. There is less intra-abdominal injury since the dissection is lateral, but higher postop pain and gait disturbance (TFL).

  • Depth of harvest: 5 cm – depth at which cortical plates fuse

  • Techniques for graft harvesting:

    • Clamshell : mid-crestal osteotomy, fold medial and lateral cortices over to expose underlying bone marrow (good technique for cancellous-only harvest) – if you need a larger quantity of bone, full-thickness corticocancellous block can be harvested (maximum 4–6 cm) – limited anteriorly by ASIS and posteriorly by tubercle of the ilium – if you want to decrease risk of fracture of ASIS, leave 3 cm of intact bone posterior to it.

    • Trapdoor : either medial or lateral cortex with attached musculature is pedicled like a hinge to gain access to marrow.

    • Tschopp : oblique osteotomy of iliac crest, pedicled onto external oblique muscle

    • Tessier: medial and lateral oblique osteotomies, both aspects pedicled to gain access

    • Trephine technique: incision only 2 cm in length, no medial or lateral stripping, trephine used to perforate crest, angulated 30° to vertical

  • Bone wax and/or microfibrillar bovine collagen can be used to aid in hemostasis. A low suction drain may also be placed to prevent postoperative hematoma.

  • Closure – need to reapproximate periosteum over crest followed by a layered closure.

Complications

  • Hematoma  – if non-expanding, pressure packing may be applied. If expanding, require surgical exploration.

  • Massive Hemorrhage  – superior gluteal artery is the usual culprit. This is caused by harvesting proximal to and/or retracting too aggressively near the greater sciatic notch. Treatment includes exploration, ligation, embolization by IR; do not try to blindly clip it or place hemostat, it has the risk of damage to the sciatic nerve or superior gluteal nerve.

  • Seroma  – needle aspiration (if large) vs. pressure dressing (if small).

  • Nerve Injury  – can be from direct injury to nerve, fibrosis, entrapment during closure, hematoma, or seroma causing external nerve compression.

    • Lateral femoral cutaneous (meralgia paresthetica).

    • Iliohypogastric (loss of sensation to lateral gluteal and suprapubic regions).

    • Subcostal nerve (loss of sensation to the lateral hip).

  • Infection of Donor Site  – removal of sutures to allow drainage. Take culture, local wound care, and antibiotics to treat infection.

  • Gait Disturbance  – stripping of TFL, gluteus medius (abductors). Normally self-limiting. Physical therapy to aid in reestablishing gait and possible walking aid in the interim.

  • Bony Fracture (ASIS, Tubercle of Ilium) – caused by harvest too close to ASIS, due to action of Sartorius and TFL muscles (stay at least 2 cm away from ASIS to avoid this complication). Management is usually nonsurgical, including pain management and bedrest (if greenstick fracture). Large fractures or significant displacement may require fixation, and an orthopedic consult is warranted.

  • Intra-abdominal Injury – this is a surgical emergency and requires an exploratory laparotomy.

  • Adynamic Ileus  – cessation of mechanical peristalsis of the bowel. This is managed by bowel rest, electrolyte correction, nasogastric suction (for decompression), and minimal use of narcotics. Should this therapy fail, promotility agents such as metoclopramide (Reglan) may restore bowel function. Most commonly this is a time-limited issue. If not self-resolving, further physical examination and imaging to rule out bowel injury is critical.

  • Sacroiliac Instability  – pain in lower back or pubis (posterior destabilization of SI joint). Fusion of SI joint may be needed in future if persistent pain.

  • Abdominal Wall Hernia  – risk factors: >4 cm block harvest, female gender, or obesity. Will require general surgery consultation.

Posterior Iliac Crest

  • Up to 100 cc of uncompressed bone available (up to 10 cm defect).

  • Superior cluneal nerve (L1–3) – pierces lumbodorsal fascia, travels superior to posterior iliac crest, and provides sensation to posterior-medial buttocks.

  • Middle cluneal nerve (S1–3) – traverses through the sacral foramina and innervates the medial buttocks.

  • Sciatic nerve (L4–5, S1–3) is 6–8 cm below the level of posterior iliac crest – should not be encountered.

  • Blood supply – perforators from the subgluteal artery.

  • Additional surgical time to reposition patient.

  • Concern for endotracheal tube displacement risk during patient maneuvering.

  • Unable to perform simultaneous procedures.

Surgical Technique

  • Patient in prone position – 210-degree reverse hip flexion.

  • 6–10 cm curvilinear incision is drawn following the course of posterior iliac crest. The superior and inferior boundaries of the field are defined by superior and middle cluneal nerves. The incision should end inferiorly approximately 3 cm lateral to gluteal crease centered over the insertion of gluteus maximus muscle (bony protuberance in triangular fossa). The area of dissection is infiltrated with local anesthetic with epinephrine.

  • The incision layers – skin, subcutaneous tissue, lumbodorsal fascia (separates abdominal and gluteal musculature), and periosteum over the posterior iliac crest.

  • The gluteus maximus muscle is stripped from the tubercle using a blade or electrocautery against the cortical bone. Additional exposure may be gained by reflection of the gluteus medius with a Keyes periosteal elevator.

  • 5 cm × 5 cm posterior iliac crest osteotomy of lateral cortical plate to access cancellous bone. Limit harvest at least 4 cm from PSIS to avoid violation of the sacroiliac joint.

  • Bone wax and/or microfibrillar bovine collagen can be used to aid in hemostasis.

  • Closure in layers; reapproximate periosteum and lumbodorsal fascia.

  • A drain should be placed to prevent postoperative hematoma.

Complications

  • Arterial Injury – superior gluteal artery, post-op gluteal compartment syndrome (treated with ligation; if continued bleeding, may need exploratory laparotomy via retroperitoneal approach, or embolization by IR).

  • Ureteral Injury – postop hematuria, abdominal distention, ileus – from excessive electrocautery usage near the greater sciatic notch (usually while you are trying to control bleeding from superior gluteal vessels). Urology consult is indicated. Treatment may include placement of a ureteral stent or surgical repair.

  • Nerve Injury – cluneal nerves, posterior pelvic pain radiating to buttocks.

  • Gait Disturbance – weak abductors (mainly gluteus medius) – from excessive stripping.

Microvascular Free Tissue Transfer

  • The term free flap (also known as autologous tissue transfer and microvascular free tissue transfer) is used to describe the transplantation of tissue with its own blood supply from one site of the body to another. The circulation in the transferred tissue is reestablished by anastomosis of the transferred arteries and/or veins to recipient vessels in the host bed (Table 9.2).

  • Free flaps may be comprised of skin, muscle, nerve, bone (or any combination of these).

Table 9.2

Free Flap Indications and Vascularity

Free flap

Components

Pedicle length/caliber

Indications

Radial Forearm Free Flap (RFFF)

Skin and fascia. Tendon (palmaris longus) if suspension is needed, bone (radius) if small bone is required.

Long pedicle if taken at take-off from brachial artery. Large caliber 2–4 cm with two venae comitantes or cephalic vein for drainage.

Thin flap is great for intraoral soft tissue defects or tongue reconstruction or lip reconstruction if tendon is included.

Anterolateral Thigh (ALT)

Skin, muscle (vastus lateralis), fascia, large flap up to 10 × 25 cm can be harvested

5–7 cm length, 1.5–3 mm diameter vessel, descending branch of the lateral femoral circumflex artery.

Large facial or intraoral defects, scalp defects, orbitocraniofacial resections, gunshot wounds. May be too thick in obese patients.

Deep Circumflex Iliac Artery (DCIA)

Vascularized iliac crest bone, iliacus muscle, with or without skin.

4–8 cm length, 1.5–3 mm diameter vessels, deep circumflex iliac artery and venae comitantes.

Maxillary or mandibular reconstruction, may require vein grafts if inadequate pedicle length.

Scapula

Skin and bone (lateral border of scapula).

Up to 7 cm length, 2–4 mm vessel diameter, subscapular artery

Mandibular ramus reconstruction, maxillary reconstruction.

Free Fibula Flap (FFF)

Bone, muscle (flexor hallucis longus cuff or adjacent soleus muscle), and skin.

Pedicle length depends on the length of bone needed but can be 5+ cm, 2–4 mm diameter vessel, peroneal artery, and venae comitantes.

Maxillary or mandibular reconstruction, can use closing osteotomies to establish arch form.

Anterolateral Thigh Flap (ALT)

  • The ALT is a fasciocutaneous perforator flap based on the descending branch of the lateral circumflex femoral artery. It runs in the intermuscular septum between the rectus femoris (RFM) and vastus lateralis muscle.

  • Long vascular pedicle length from 8–16 cm if measured the entire length of the flap.

  • Flap is fairly thick due to the presence of copious subcutaneous tissue. Some authors have described “defatting” the flap at the time of harvest to thin the flap; however, this carries the risk of compromising venous circulation within the flap.

  • The flap can be raised with only fascia and thin subcutaneous fat without the skin. This will result in a much thinner fascial flap.

  • Popular due to the versatility of the flap in design.

  • Donor site can often be closed primarily leading to minimal donor site morbidity.

Surgical Technique

  • A line is drawn from the anterior-superior iliac crest to the lateral aspect of the patella. This line roughly corresponds to the intermuscular septum between the rectus femoris and vastus lateralis muscles. At the midpoint of this line, a 5 cm circle is scribed (centered on the line). Within this circle (the lateral two quadrants most commonly) is where perforating vessels can be most readily identified. Once this is accomplished, the flap is designed centered over the perforator.

  • Flap elevation begins by making a skin incision along the medial margin of the flap. This is carried through the skin, subcutaneous tissue, and fascia over the rectus femoris muscle.

  • Once in the subfascial plane, gentle blunt dissection can be carried laterally until the perforating vessels are identified. (Most commonly the perforating vessels are muscular and pierce the vastus lateralis muscle. About 9% of the time, the perforators are septal. The presence of septal perforators does simplify flap harvest but when muscular perforators are encountered, a small cuff of vastus lateralis can be safely taken to protect the perforator.)

  • Once the perforator is identified, the intermuscular septum between the vastus lateralis and rectus femoris muscles is dissected and the flap pedicle can be identified. (Motor nerve branches to the vastus lateralis muscle are commonly seen running with the artery and can be separated and preserved.)

  • The pedicle is traced back to the takeoff from the lateral circumflex femoral artery. The flap is then incised around the lateral aspect.

  • The fasciocutaneous portion of the flap is completely dissected. (Perforators are dissected from the muscle if needed.)

  • Once the tumor is ablated and the size of the defect is defined, back cuts are made on flap to the desired size and modified as required.

  • Vessels are clamped proximally and ligated, and the flap is delivered from donor site.

  • Donor sites up to 8–10 cm wide can usually be closed primarily; if the flap is larger than this, skin graft closure can also be used but is less cosmetically pleasing.

Complications

Specific to the ALT flap paresthesia or anesthesia over the lateral thigh, seroma formation, wound infection. Paresthesia over the lateral thigh is not usually very bothersome. Seromas may require drainage and infections should be treated with antibiotics to cover for skin flora.

Herniation of Muscle

There are reports of vastus lateral and rectus femoris muscle herniation . Requires exploration and repair. Repairs include direct closure or coverage with a split thickness skin graft. Larger hernias may be treated with a polypropylene mesh [3, 4].

Rectus Femoris Muscle Necrosis [4]

Uncommon complication from ligation of the lateral circumflex artery proximal to take-off of the descending branch during harvest. Authors recommend when a larger pedicle is needed to place a vessel loop at the site of planned vessel harvest prior to definitive ligation to evaluate blood flow to the rectus femoris muscle.

Compartment Syndrome [4]

Increase in pressure within a closed fascial space resulting in a decrease in capillary flow. If the deep fascia was used for closure, treatment describes release of the deep fascia. If deep fascia closure was not performed and compartment syndrome was discovered, debridement with VAC therapy has been described.

Radial Forearm Free Flap

  • The radial forearm free flap is a fasciocutaneous flap based off the radial artery.

  • Venous outflow is provided by either the venae comitantes or the cephalic vein.

  • Used mostly for floor of mouth, tongue, lip, and buccal mucosa reconstruction. Defects that require more bulky tissue such as subtotal glossectomy and large skull base tumors are better suited with a bulkier flap such an ALT [5, 6].

  • This flap is also being described to include a portion of the radial bone, the palmaris longus tendon, or brachioradialis muscle.

  • Because the skin of the volar forearm is quite thin and pliable, this flap has become a workhorse flap in oral cavity, laryngeal and pharyngeal reconstruction. It is also useful for resurfacing defects where a thinner flap is desirable.

  • Long vascular pedicle with large caliber vessels allows for easy anastomosis.

  • There are usually no long-term sequelae of the donor site with hand and wrist mobility and finger strength being preserved in usual flap harvests.

  • Major complaint is unaesthetic donor site due to scarring or poor color match when skin grafts are used for closure.

Preoperative Considerations

  • Note any recent intra-arterial or intravenous lines placed as they may compromise flap vascularity. “No stick” order should be placed for patients presenting for reconstruction.

  • Best to harvest from non-dominant hand in the event that there is a donor site complication that would compromise the hand or reduce hand strength or mobility.

  • A preoperative Allen test is useful for determining whether the patient has acceptable ulnar collateralization. Many patients undergoing oral cavity reconstruction have poor peripheral circulation and an Allen test can be difficult to interpret. Therefore, the use of a pulse oximeter on the thumb when doing the test can improve sensitivity of the exam. Adequate compression of the ulnar and radial arteries should result in complete cessation of the arterial waveform on the pulse oximeter. Release of the ulnar artery should result in return of pulsatile flow but with an attenuated waveform. Then, release of the radial artery should result in restoration of the complete amplitude of the waveform. (In the traditional description, reperfusion of the fingers or nail beds should be seen in 15–20 seconds). In this scenario, adequate ulnar collateral flow is evident, and the patient should tolerate radial artery harvest without a risk for devascularization.

  • Further vascular imaging studies are generally not necessary. In the event that the patient has a concerning Allen test, the patient can still undergo radial forearm free flap harvest; however, the radial artery should be reconstructed immediately with vein grafting. While the cephalic vein is commonly used for venous outflow of the flap, it can be used for reconstruction of the radial artery while the venae comitantes are used for the venous circulation of the flap.

Radial Forearm Harvest Technique

  • The radial artery is palpated and marked as is the cephalic vein. The appropriately sized flap is then drawn over the radial and volar surface of the forearm centered over the radial artery. The distal aspect of the flap margin is marked approximately 1 cm from the distal wrist crease.

  • A tourniquet is utilized and inflated to 250 mmHg for exsanguination.

  • Flap elevation begins at the distal aspect of the segment. A#15 blade is used to incise the skin, subcutaneous tissue, and fascia along the distal margin of the flap. Curved hemostats are then used to dissect the cephalic vein as well as the radial artery and radial artery venae comitantes. They are then ligated and transected.

  • Next, starting on the medial and distal corner, the flap is elevated in a subfascial plane. Care must be taken during this portion of the flap elevation to avoid dissecting the fascia from the radial artery. When elevating the flap over the flexor carpi ulnaris, palmaris longus, and flexor carpi radialis tendons, the paratenon over those tendons should be preserved to aid in skin graft take.

  • Flap elevation is continued to the radial distal edge and, while lifting the flap, the two superficial dorsal branches of the radial nerve can be identified and left in place during flap elevation. This minimizes paresthesia over the dorsum of the hand along the thumb and index finger. Once the flap is elevated to the proximal margin, the proximal aspect of the flap is incised with care not to transect the cephalic vein.

  • Releasing incision is then opened to the antecubital fossa. Vessel loops are placed around the cephalic vein distally and this vein is followed proximally and dissected out of the subcutaneous tissues with care being taken to ligate and divide any branches.

  • The brachioradialis muscle is retracted laterally and the flap is elevated to place gentle tension on the radial artery. Vessel loops were placed around the radial artery and it is traced proximally as branches are ligated and divided.

  • The cephalic vein and radial artery are traced to the antecubital fossa both in order to provide adequate pedicle length and also to improve vessel caliber.

  • The tourniquet is deflated, and the flap is reperfused for 20 minutes.

  • The flap can then be harvested by ligating and dividing the radial artery and two venae comitantes as well as the cephalic vein.

  • The flap is passed into the oral cavity for inset and anastomosis.

  • Closure of the radial forearm donor site is most commonly accomplished by primary closure of the releasing incision and then skin graft application over the flap donor defect. Some surgeons prefer a full-thickness skin graft harvested from the medial surface of the upper arm as this area is already prepped into the surgical field and a full-thickness skin graft gives thicker coverage for the flexor tendons. Others will utilize a split thickness skin graft harvested from a distant site such as the thigh.

  • If a skin graft is used, it should be perforated to allow seepage of fluid. A bolster is kept in place for 5–7 days and the splint is kept in place for 4 weeks.

Complications

Delayed Wound Healing

Failure of the skin graft resulting in tendon exposure, infection, and decreased mobility of the wrist or fingers due to scarring. Treatment options depend on the extent of necrotic tissue. The tissue may be debrided and a second skin graft attempted. The defect may be allowed to heal by secondary intention, by covering with moist gauze until healed [7, 8].

Hand Ischemia

Can normally be avoided if Allen test is properly conducted, or can use color flow doppler if Allen test is not conclusive [811]. Can occur if the radial artery is the major blood supply to the hand, damage to the ulnar artery, or insufficient collateral blood flow between arterial systems. Treatment is an interpositional vein graft to the divided stump from either the saphenous or cephalic vein.

Decreased Pincer Grasp and Hand Strength

Can result from harvesting a portion of the radial bone.

Infection

Antibiotics with activity against skin flora are indicated if signs of infection are present. Serial debridement of necrotic material and irrigation of the wound is recommended. Cultures should be taken and considered for infectious disease consultation.

Nerve Injury

Complaint of dysesthesia in the distribution of radial nerve, but this becomes less noticeable overtime [8, 10].

Fibula Free Flap

  • Excellent option for reconstruction of any mandible defects (most commonly from neoplasm, osteonecrosis, and trauma).

  • Ideal for composite osseous defects that require reconstruction of adjacent oral lining or external skin.

  • The fibula is a long, thin bone that articulates with the lateral condyle of the tibia proximally and with the connective tissue of the ankle mortise distally. It is a non-weight bearing bone with a relatively thick cortex circumferentially.

  • Bone height varies from 9 to 15 mm with a total length of approximately 35 cm, typically up to 25 cm can be harvested.

  • The peroneal artery (PA) and its venous comitantes provide vascular supply to the fibular free flap. The external diameter of the peroneal artery is 1.5–2.5 mm and the pedicle length is between 2 and 6 cm [12].

Fascial Compartments

  • The lower leg is separated into compartments dictated by the tibia and fibula bones as well as fascial planes (Fig. 9.1).

  • The tibia and fibula with their interosseous septum separate the anterior and posterior compartments. The anterior lower leg is further subdivided into anterior and lateral compartments by the anterior intermuscular septum.

  • The posterior lower leg is subdivided into deep and superficial compartments by the transverse intermuscular septum.

  • The lateral and posterior compartments are separated by the posterior intermuscular septum which importantly carries the skin perforator vessels essential to skin paddle harvest.

  • Knowledge of these fascial compartments and their contents is essential when harvesting a fibular flap.

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Fig. 9.1

1 Tibialis anterior; 2 extensor digitorum and hallucis; 3 peroneus longus; 4 tibialis posterior; 5 soleus; 6 gastrocnemius lateralis (6a) and medialis (6b). (Reprinted with permission from Silvestri et al. [13])

Preoperative Workup

The integrity of the lower limb and foot vasculature is essential before planning for a fibular free flap. Work up should be focused on identifying abnormal vascular patterns to the foot as well as identifying compromised vessel quality. Imaging is recommended to confirm three vessel run-off.

History

  • Inquire about cardiovascular disease risk factors (coronary artery disease, peripheral vascular disease, smoking, etc.).

  • Specifically check for history of claudication, dependent edema, venous thrombosis, varicose veins, prior lower limb surgery, and prior lower limb trauma.

Physical Exam

  • Inspect for signs of peripheral vascular disease including edema, induration, varicosities, shiny/hairless skin, and cold feet.

  • Palpate dorsalis pedis and posterior tibial pulses.

    • “Modified” Allen test: Apply pressure to dorsalis pedis artery while palpating for posterior tibial pulse and vice versa to eliminate retrograde flow.

  • ABI (Ankle-Brachial Index): Objective measure to detect arterial insufficiency although its use is primarily historical in this setting due to improved imaging modalities.

Imaging

  1. 1.

    Magnetic Resonance Angiography.

     
  2. 2.

    Computed Tomographic Angiography (Fig. 9.2).

     
  3. 3.

    Conventional Angiogram.

     
  4. 4.

    Color-Flow Doppler Imaging (may also play a role in localizing perforators).

     
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Fig. 9.2

Peronia Arteria Magna of right lower leg on angiography. Lower left leg demonstrating all three vessel branches of the popliteal artery (1) anterior tibial (AT) (2) posterior tibial (PT) and (3) peroneal artery. (Reprinted with permission from Betz and Betz [14])

Guidance Point

PVD doesn’t necessarily preclude use of FFF; however, there is a higher risk of thrombotic events and flap complications. Other osteocutaneous flaps should be considered in these patients, such as the scapula, since the vascular supply is more proximal and less affected by PVD.

Variation in Arterial Supply

  • Surgically significant anomalies occur in 10% of population, 5.2% of any given limb.

  • Variations are clinically asymptomatic but impact surgical candidacy.

  • Infra-popliteal Arterial Branching Classification (Kim-Lippert’s Classification System) [15]:

    1. I:

      Normal level of branching

       
    2. II:

      High-Division of PA (at or right above the knee)

       
    3. III:

      (10.37% Overall) Hypoplastic/aplastic branching with altered distal supply (Table 9.3).

       
    4. IV:
      PA vessel caliber variation

      • IV-A: Hypoplastic (not recommended, but may not fully preclude FFF harvest given anastomoses of vessels as small as 1 mm possible)

      • IV-B: Aplastic (absolute contraindication)

       
Table 9.3

Type III subtypes of lower leg branching patterns

Type III (10%)

Subgroup

IIIA

IIIB

IIIC

Notes

2-vessel runoff

Deficient vessel: PT (63%)

2-vessel runoff

Deficient vessel: AT (29%)

Single-vessel runoff (Peronia Arteria Magna). See Fig. 9.2.

Deficient vessel: Both tibial arteries (8%)

Implication

Possible but unwise

Possible but unwise

Absolute contraindication

Fibula Free Flap Technique

Jul 23, 2021 | Posted by in Oral and Maxillofacial Surgery | Comments Off on 9. Reconstruction
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