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Free Flap Head and Neck Reconstruction:

A 12-year experience with 950 cases

Keith E. Blackwell, MD Professor of Surgery Division of Head and Neck Surgery David Geffen School of Medicine at UCLA

2008 Plastic Surgery Symposium


I am a consultant for Stryker Craniomaxillofacial, which makes medical devices used during head and neck reconstructive surgery

Microvascular Free Flaps

Free Flaps

· Distant tissue transfer based upon microvascular anastomoses · Developed in the early 1970's · Not widely utilized until the 1990's due to perceived complexity and questions regarding reliability

Fibula free flap, UCLA Medical Center



· To review a 12-year experience with 950 consecutive cases of microvascular head and neck reconstruction · To review the indications, advantages, and disadvantages of free flaps commonly used for head and neck reconstruction


· To identify the incidence, etiology, and factors associated with the complications of treatment · To report preliminary findings with regards to the speech and swallowing outcome after free flap reconstruction of the mouth and throat

Analysis of Complications

· 400 consecutive patients analyzed · Factors analyzed: age, sex, diagnosis, comorbidity level (ASA status), tumor stage, defect site, delayed vs. immediate reconstruction, and history of prior surgery, radiation therapy, or chemotherapy, flap type · Main outcome measures: Perioperative complications


Speech and Swallowing Outcome

· Subjective analysis of 110 patients with oral cavity/oropharyngeal reconstruction · Minimum cancer- free follow up of 12 months · Average follow up period was 37 months (range 12 months to 108 months) · Speech outcome:

­ Good: easily intelligible ­ Moderate: impaired intelligibility but functional ­ Poor: unintelligible

· Swallowing outcome:

­ Good: soft or solid food diet ­ Moderate: liquid diet ­ Poor: tube feedings

Patients and Methods

· 950 consecutive free flaps were performed between August 1995 and November 2007. · Setting: Academic tertiary care medical centers

­ UCLA, Greater Los Angeles VA, UCLAaffiliated LA County, Cedar Sinai, and Kaiser Sunset Medical Centers

Patients and Methods

· Sex: 621 men and 329 women · Age range:11 to 90 years · Underlying pathology

­ Malignant or benign neoplasm in 95 % ­ Traumatic or congenital deformity in 5 %

Advanced oral cancer


Defect Classification

· 81 % Oral cavity / oropharyngeal defects · Most common indication: reconstruction of segmental defects of the mandible accounted for about 50% of cases · 7 % Skull base-midface defects · 12 % Pharyngoesophageal defects

Free Flap Selection

· · · · · · · · Radial forearm flaps (n=398) Fibula flaps (n=391) Subscapular system flaps (n=80) Rectus abdominis flaps (n=48) Anterolateral thigh flaps (n=26) Iliac crest flaps (n=5) Gracilis flap (n=1) Jejunal flap (n=1)

} 83%

Radial Forearm Flap

· 397 fasciocutaneous flaps · 1 osteocutaneous flap · Thin, pliable flap

Fasciocutaneous radial forearm flap


Radial Forearm Flap

Neurovascular Anatomy · Arterial supply: radial artery and · Venous drainage: radial venae comitantes (2) and cephalic vein · Lateral antebrachial cutaneous nerve

Radial Forearm Flap

Common indications · Oral & oropharnygeal reconstruction for restoration of complex 3-D anatomy · Oral cavity reconstruction for preservation of tongue mobility · Pharyngoespophageal reconstruction using tubed flaps

Radial Forearm Flap:

Reconstruction of Complex 3-D Anatomy

· Recurrent squamous carcinoma of left buccal mucosa · Prior treatment by surgery and radiation therapy · Thu & thru excision of buccal mucosa and cheek skin

Buccal SCCA


Radial Forearm Flap: Case example

Flap centered on radial artery and cephalic vein

Vascular pedicle dissected

Harvest of fasciocutaneous flap

Radial Forearm Flap: Case example

· Radial forearm flap used for reconstruction of buccal mucosa · Cervicofacial rotation flap used for reconstruction of cheek skin

Radial Forearm Flap

4 month postoperative appearance


Radial Forearm Flap:

Preservation of Tongue Mobility · Right hemiglossectomy with preservation of tongue projection after radial forearm flap reconstruction

Right hemiglossectomy

Forearm Flap Indications

· Pharyngoesophageal reconstruction · Thin flap easily tubed upon itself · 85 % resume oral nutrition · Better speech quality than jejunal flap · Fistulas: 20 % · Strictures: 20 %

A: oropharyngeal enteric anastomosis C: esophageal enteric anastomosis B: Flap tubed upon itself

Fibula Flap

· Vascularized bone containing flap · Thin, pliable skin paddle

Osteocutaneous fibula flap


Fibula Flap

Common indication · Work horse flap for oromandibular reconstruction · Maxillary reconstruction in cases where prosthetic rehabilitation is difficult

Mandible Reconstruction

405 cases of segmental mandibulectomy reconstruction · 322 fibula flaps (80 %) · 46 soft tissue flaps with bridging mandibular reconstruction plates (11 %) · 30 subscapular system flaps (8 %) · 5 iliac crest flaps · 1 osteocutaneous radial forearm flap · 1 rectus abdominis with rib flap

Fibula Flap

Neurovascular Anatomy · Arterial supply: Peroneal artery

­ Endosteal supply via a medullary branch ­ Periosteal supply via numerous periosteal branches ­ Septocutaneous and septomuscular branches to skin

· Venous Drainage: Peroneal veins (2) · Sensory reinnervation: Lateral sural cutaneous nerve


Fibula Flap Case Example

· Advanced basal cell carcinoma of the lip, chin, and mandible · Neglected for 20 years · Severe deformity, swallowing and speech impairment

Fibula Flap Case Example

· Skin paddles as large as 550-cm2 have been used for reconstruction of through-and-through defect · Increase risk of marginal necrosis of skin paddle when it exceeds 300-cm2

Fibula Flap Case Example

Preoperative appearance

Postoperative appearance


Fibula Flap

3 week postoperative appearance

Fibula Flap Advantages

Dental implants in a fibula flap

Fibula donor wound with skin graft reconstruction

Advantages: · Limited long-term donor site morbidity · Bone stock suitable for dental implants

Fibula Flap Advantages


· Subperiosteal dissection and excision of the unneeded length of proximal bone graft provides a long vascular pedicle containing large diameter vessels. Vein grafts rarely needed even when using recipient vessels in the contralateral neck


Fibula Flap Disadvantages

Disadvantages: · Propensity for peripheral vascular disease · Skin paddle characteristics

­ Hair bearing skin in men ­ Thin subcutaneous layer may lack adequate bulk ­ Poor mobility of skin relative to bone secondary to cutaneous perforators

Fibula Flap Disadvantages

Disadvantages: · Bone is poor match for mandibular height · This may result in eventual loosening of dental implants, which are exposed to a torque force during mastication

Dental implants in a fibula flap

Fibula Flap Disadvantages

· Complete failure of skin paddle in about 1% of cases · Risk of partial skin paddle necrosis is 50 % when skin paddle area exceeds 300-cm2

Angiosomes of the lateral leg


Skin Paddle Necrosis

Preoperative appearance

Defect after cancer resection

Advanced recurrence SCCA lower lip

Skin Paddle Necrosis

Immediate appearance

24-hour appearance

Immediate and 24-hour postoperative appearance

Skin Paddle Necrosis

Secondary reconstruction with deltopectoral flap


Skin Paddle Necrosis

Secondary reconstruction with deltopectoral flap

Fibula Flap Disadvantages

· Early donor site morbidty

­ ­ ­ ­ Pain Swelling Impaired ambulation Skin graft failure on leg tendons

Skin graft failure

Subscapular System Flaps

A wide variety of bone and soft tissue grafts perfused by the subscapular artery are available for transfer Vascular anatomy: · Subscapular artery bifurcates to form the circumflex scapular artery and the thoracodorsal artery


Subscapular System Flaps

Circumflex scapular artery supplies: · Scapular fasciocutaneous flap · Parascapular fasciocutaneous flap · Lateral border of scapula bone (10 to 14cm length)

Subscapular System Flaps

Thoracodorsal artery supplies: · Latissimus dorsi muscle and overlying skin · Serratus anterior muscle and ribs enveloped by serratus muscle · Inferior tip of the scapula bone via the angular branch of the thoracodorsal artery

Latissimus Dorsi Flap

· Broad, thin muscle harvested from the flank · Useful for resurfacing large areas of the head and neck

Cheek and temple reconstruction


Scalp Reconstruction

· Advanced SCCA scalp with invasion of periosteum

Scalp Reconstruction

· Coverage of calvarium with latissimus dorsi serratus anterior myofascial flap

Scalp Reconstruction

· Skin graft coverage of myofascial flap


Scalp Reconstruction

· 2 week postoperative appearance

Latissimus Dorsi Flap

2 years postoperative scalp reconstruction

Latissimus Dorsi Flap

· Myocutaneous flap is preferred in cases of scalp reconstruction where there is excision of the dura and/or alloplastic cranioplasty, to reduce risk of CSF leak or cranioplasty extrusion


Latissimus Dorsi Flap

Scalp Reconstruction

Latissimus Dorsi Flap

Scalp Reconstruction

Latissimus Serratus Rib Osteomyocutaneous Free Flap

· Often my flap of choice when peripheral vascular disease precludes transfer of a fibula flap · Can be harvested with patient in supine position using a mid-axillary incision, allowing for simultaneous two-team surgery · Soft tissue characteristics superior to iliac flaps


Latissimus Serratus Rib Flap

Supine position during harvest

Flap harvested

Latissimus Serratus Rib Flap

· 20-year-old woman a massive gigantiform cementoma on the mandible and maxilla · Misdiagnosed as fibrous dysplasia · Treated by periodic recontouring for 10 years · Clinical course marked by relentless tumor progression Preoperative frontal view

Latissimus Serratus Rib Flap

· Also afflicted with osteogenesis imperfecta resulting in more than 80 extremity fractures in the past · Few bone grafts available · Several surgeons had told her that her case was hopeless Preoperative lateral view


Gigantiform Cementoma

Mandible Preoperative Facial CT Scan


Osteogenesis Imperfecta

Preoperative x-rays

Latissimus Serratus Rib Flap

· Staged treatment of mandible and maxilla undertaken · Initial angle to angle mandibulectomy with serratus anterior rib flap reconstruction

Mandibulectomy specimen


Latissimus Serratus Rib Flap

· Staged bilateral maxillectomy with latissimus dorsi serratus anterior rib flap reconstruction

Bilateral maxillectomy

Latissimus Serratus Rib Flap

Preoperative frontal view

Early postoperative frontal view

Latissimus Serratus Rib Flap

Preoperative lateral view

Early postoperative lateral view


Latissimus Serratus Rib Flap

· Appearance 4 years after mandible reconstruction and 3 years after midface reconstruction: nonunion to R zygoma

Latissimus Serratus Rib Flap Bone graft reliability · 28 latissimus serratus rib flaps performed

­ One case of partial rib graft resorpion noted 22 months postoperatively ­ One case of nonunion noted at 56 months postoperatively

Subscapular System Flaps

Advantages · Wide variety of tissue components available bases upon independent vascular pedicles, allowing for single flap reconstruction of very complicated defects · Skin is a relatively good match for facial and neck skin compared to other flaps


Subscapular System Flaps

· Lateral scapular border is suitable for placement of dental implants in most men · The vascular pedicle is long and contains large caliber blood vessels

Serratus rib flap with 25-cm long vascular pedicle

Subscapular System Flaps

Disadvantages · Decubitus positioning is needed to harvest flaps based upon the circumflex scapular system · A limited length of scapula bone stock is available, and scapula bone in women may not accept dental implants · Rib is a poor substitute for mandible and will not accept dental implants

Anterolateral Thigh Flap

· Increasing popularity for head and neck reconstruction · Body habitus affects flap characteristic · Flap can be thin and pliable or thick and bulky


Anterolateral Thigh Flap Indications

Thin Flaps: · Oral cavity reconstruction · Pharyngoesophageal reconstruction Thick Flaps: · Skull base and midface reconstruction · Total glossectomy

Anterolateral Thigh Flap

Neurovascular Anatomy · Arterial supply: lateral circumflex femoral artery · Venous drainage: lateral circumflex femoral vein · 90% of perforators have a musculocutaneous course through the vastus lateralis muscle · Sensory reinneration: lateral femoral cutaneous nerve

Anterolateral Thigh Flap

Parotid SCCA Preop CT scan

Recurrent squamous carcinoma of parotid gland


Anterolateral Thigh Flap

Specimen Defect

Radical parotidectomy, resection of lateral temporal bone, zygomatic arch, condyle, and auricle

Anterolateral Thigh Flap

Flap design

Vascular pedicle

Flap harvest

Anterolateral Thigh Flap

Revascularized to facial artery & EJ vein

Flap inset with reconstruction of EAC

Flap revascularized and inset


Anterolateral Thigh Flap

Primary closure of donor site wound for flaps up to 12-cm wide

Anterolateral Thigh Flap

2 week postoperative appearance

Anterolateral Thigh Flap

6 month postoperative appearance (different patient)


Anterolateral Thigh Flap

Preop MRI scan

Defect after laryngopharyngoesophagectomy

Recurrent SCCA hypopharynx after chemoXRT

Anterolateral Thigh Flap

Vascular pedicle and nerves to quadriceps

Flap harvested

Pharyngoesophageal reconstruction

Anterolateral Thigh Flap

Flap tubed

Flap inset and revascularized using right transverse cervical vessels

Pharyngoesophageal reconstruction


Anterolateral Thigh Flap


4 months postop

Total glossectomy reconstruction

Rectus Abdominis Flap

· Thick, bulky myocutaneous flap · Deep inferior epigastric artery and vein

Flap harvested

Rectus Abdominis Flap

Common indications · Total glossectomy reconstruction · High volume skull base and midface defects · I now prefer anterolateral thigh flaps in many cases where I have used rectus flaps in the past


Tongue Reconstruction

· Reconstruction of tongue mound height in a patient with a rectus abdominis flap reconstruction.

Total glossectomy with rectus flap

Skull Base Reconstruction

· Obliteration of high volume defects · Coverage of exposed dura/brain · Separation of intracranial contents from aerodigestive secretions

Temporal bone resection



Iliac Crest Flap

Neurovascular Anatomy · Arterial supply: Deep circumflex iliac artery.

­ 1.5 to 3-mm diameter

· Venous drainage: Deep circumflex iliac vein.

­ 2 to 4-mm diameter

· Pedicle length 5 to 7-cm · Sensory reinnervation of skin paddle: lateral cutaneous branch of the 12th thoracic nerve


Iliac Crest Flap

Bone Graft Considerations

· The ipsilateral ilium approximates the size and shape of the mandible · To reconstruct the ipsilateral hemimandible without osteotomy, the ASIS becomes the mandibular angle · The bone between the ASIS and the AIIS becomes the ascending ramus · Up to 16-cm of bone is available along the iliac crest, and osteotomies can be made to extend beyond the mandibular midline

Iliac Crest Flap

Bone Graft Considerations · Bicortical bone graft provides excellent match for native mandibular height and width · Monocortical bone graft (inner table) greatly reduces donor site morbidity

Iliac Crest Flap

Two soft tissue components are available: · Skin paddle ­ Thick and bulky · Internal oblique muscle ­ Thin and pliable


Iliac Crest Flap

Case Illustration

· Osteoradionecrosis of the mandible and temporal bone after surgery and neutron beam radiation therapy for left parotid cancer · Symptoms: severe pain, trismus, dysphagia, and malnutrition

Iliac Crest Flap

Case Illustration · The soft tissues were severely contracted and fibrotic, requiring soft tissue reconstruction of the buccal mucosa and neck skin

Iliac Crest Flap

Case Illustration · An iliac crest internal oblique osteomyocutaneous flap was designed for reconstruction.


Iliac Crest Flap

Case Illustration · The wound consisted of a through & through defect of floor of mouth and buccal mucosa, hemimandibular bone, and submandibular neck skin

Iliac Crest Flap

Case Illustration · The iliac bone graft approximated the size of shape of the mandibulectomy specimen. No osteotomies were needed to created the needed mandibular curvature

Iliac Crest Flap

Case Illustration · The internal oblique muscle was used to reconstruct the deficient intraoral mucosa


Iliac Crest Flap

Case Illustration · The skin paddle was used to expand the contracted submandibular neck skin

7 Years Postoperative Appearance

· · · ·

Persistent facial contour deformity Improved trismus Improved nutrition, weight gain Resolution of chronic pain

Iliac Crest Flap Advantages

Advantages · A bulky soft tissue component is available for reconstruction of high volume soft tissue defects (e.g. total glossectomy) · A thin soft tissue component available for low volume defects


Iliac Crest Flap Advantages

Advantages · Suitable bone stock for dental implants · Excellent match of native mandibular height

Iliac Crest Flap Advantages

· Postoperative radiographs demonstrate excellent match of native mandibular height

Iliac Crest Flap

Disadvantages · Significant postoperative donor site pain · Potential long-term donor site morbidity

­ ­ ­ ­ Hernia (as high as 10 % in large series) Femoral nerve palsy Gait disturbance Contour deformity of abdominal wall


Iliac Crest Flap

Disadvantages · Skin paddle is poorly mobile relative to bone graft and excessively bulky for most oral soft tissue defects · When using the ipsilateral ilium for hemimandibular reconstruction, the bulky skin paddle is located lateral to the bone graft, interfering with aesthetic result

Gracilis Flap

· Reinnervated myofascial flap · Main indication is facial reanimation:

­ Resection of distal facial nerve branches and/or mimetic muscles ­ Longstanding or congenital facial paralysis

Gracilis flap harvested with adductor vascular pedicle and obturator nerve

Gracilis Flap

· Vascular pedicle: adductor artery and vein branches of the profunda femoris vessels · Motor nerve supply: anterior branch of obturator nerve

Obturator nerve entering gracilis muscle 3-cm superior to the adductor vessels


Gracilis Flap

· Lower facial paralysis and concavity after excision of right cheek venous malformation

Gracilis Flap

· Flap is harvested from the medial thigh · Adductor longus muscle is retracted anteriorly to reveal the neurovascular pedicle

Gracilis Flap

· · · ·

Dynamic sling from zygomatic arch to oral commisure Nerve anastomosis to lower division of facial nerve Vascular anastomosis to superficial temporal vessels Muscle bulk restores cheek contour


Gracilis Flap

18 months postoperative appearance

Free Flap Complications

Perioperative Mortality: 0.8 %(8/950) · Tension pneumothorax after iliac flap · Unknown cause of death after rectus flap · Pulmonary embolism after rectus flap · Liver failure after fibula flap · Myocardial infarction after fibula flap · Carotid blowout after fibula flap · Unknown cause of death after fibula flap · Cardiac arrythmia after ALT flap

Free Flap Complications

Free Flap Failure Rate: 0.6 % (6 of 950 flaps) · Venous thrombosis of fibula flap on POD2 · Venous thrombosis of fibula flap on POD4 · Arterial thrombosis of fibula flap on POD1 · Arterial thrombosis of fibula flap on POD1 · Arterial thrombosis of fibula flap on POD4 · Arterial thrombosis of fibula flap on POD5


Improved Free Flap Reliability

Free flap survival · During the first decade of microvascular surgery, the rate of successful free tissue transfer was 89 %

Davies DM. A world survey of anticoagulation practice in clinical microvascular surgery. Br J Plast Surg. 1982; 35: 96-99.

Improved Free Flap Reliability

During the second decade of microvascular head and neck reconstruction, free flaps were reported to be more reliable

· University of Pittsburgh: 91.2 % success rate in 305 flaps in 1996 · MD Anderson: 94.5 % success rate in 308 flaps in 1994 · Mount Sinai: 93.5 % success rate in 200 flaps in 1994

Improved Free Flap Reliability

The rate of successful microvascular head and neck reconstruction is now approaching 100 % at some centers

· Sloan Kettering: 98.6 % success rate in 728 flaps reported in 2001 · University of Pennsylvania: 99.4 % success rate in 200 flaps reported in 2001 · UCLA: 99.5 % success rate in 739 flaps


Factors Resulting in Improved Free Flap Reliability

· Heavy reliance on flaps with long vascular pedicles containing large caliber blood vessels · Historically, the majority of head and neck defects have been reconstructed using one of 3 donor sites that offer these vascular pedicle characteristics:

­ Radial forearm free flap: thin soft tissue flap ­ Fibula free flap: bone flap ­ Rectus abdominis flap: thick soft tissue flap

Free Flap Selection Resulting in Improved Reliability

Medical Center Forearm, fibula, and rectus flaps as % of total cases performed 81.2 % 91.7 % 90 %

Sloan Kettering U. Pennsylvania UCLA

Flap selection vs. Flap failure

Fibula flaps 391 cases Fibula flap failures 6 cases (1.9 %) Other flaps 559 cases Other flap failures 0 cases (0 %)

Chi-squared=8.6, p<0.01


Gender vs. Flap failure

Male flap cases 621 Male flap failures 1 (0.2 %) Female flap cases 329 Female flap failures 5 (1.5 %)

Chi-squared=6.52, p<0.03

Factors Associated with Complications: 400 cases

Perioperative Complications · Perioperative complications occurred in 144 of 400 cases (36 %) · Perioperative complications related to the reconstruction occurred in 76 of 400 cases (19 %) · Perioperative medical complications occurred in 82 of 400 cases (21 %)

Medical Complications in 400 Free Flaps

Common (>5 %)

· Respiratory 40/400 (10%) · Cardiac 31/400 (7.8 %) · Infectious 30/400 (7.5 %) Rare (< 5%) · Gastrointestinal 16/400 · Hematological 15/400 Neurological 6/400 · Psychiatric 6/400 · Death 5/400 · Genitourinary 4/400 · Vascular 4/400 · Integumentary 4/400 · Endocrine 3/400


Reconstructive Complications in 400 Free Flaps

Reconstructive Complications

· · · · · · · · Donor wound 23/400 (5.8 %) Skin necrosis 13/400 (3.2 %) Partial flap necrosis 12/400 (3 %) Wound infection 11/400 (2.8 %) Salivary fistula 11/400 (2.8 %) Hematoma 9/400 (2.3 %) Free Flap Failure 3/400 (0.75 %) Hardware 1/400 (0.3 %)

Incidence of Wound Healing

Uncomplicated wound healing in the head and neck is more common after microvascular flap reconstruction when compared to pedicled flap reconstruction:

Free flaps:

Total flap necrosis: 1 % Partial flap necrosis: 3 % Salivary fistula: 3 %

Pectoralis major myocutaneous flap: Total flap necrosis: 1 % Partial flap necrosis: 20 % Salivary fistula: 15 %

(published series from Sloan Kettering, UCLA, and MD Andersen)

Statistical Analysis: Complications in 400 Free Flaps

Overall perioperative complications associated with: · ASA status (p=0.001)

(Univariate chi square analysis)


Statistical Analysis: Complications in 400 Free Flaps

Reconstructive Complications associated with: · Previous surgery (p=0.002)

(Multivariate analysis using logistical regression)

Statistical Analysis: Complications in 400 Free Flaps

Medical Complications associated with: · ASA status (p=0.04) · Age (p=0.002)

(Multivariate analysis using logistical regression)

Oral/oropharyngeal Reconstruction Speech Outcome


31 % 65 %

Good Moderate Poor

110 patients with minimum 12 months follow up


Oral/oropharyngeal Reconstruction Swallowing Outcome

19 %

60 % 21 %

Good Moderate Poor

110 patients with minimum 12 months follow up

Swallowing Outcome

· Multiple patient, tumor, defect, and reconstructive factors were analyzed in patients undergoing surgery for cancer of the oral cavity and oropharynx · Outcome: aspiration as determined by an early postoperative modified barium swallow · Incidence of aspiration was greater than 50 % for patients with resection of more than half of the tongue base and preoperative radiation therapy

Pharngoesophageal Reconstruction Speech & Swallowing Outcome

Fasciocutaneous flaps (RFFF and ALT) · 85 % of patients achieve oral alimentation · 20 % of patients developed strictures, most managed by dilation · 20 % incidence of fistulas without salivary bypass tubes · Reduced incidence of fistulas (about 6 %) seen during last 2 years with routine placement of a salivary bypass tube for 2 to 3 weeks after surgery · Tracheoesophageal speech quality if superior to that achieved with jejunal flaps



· Free flaps are extremely reliable for reconstruction of wounds in the head and neck region. · The incidence of primary wound healing after free flap reconstruction is higher than that achieved using other methods of reconstruction.


In patients whom undergo microvascular head and neck reconstruction: · Perioperative complications correlate with ASA status · Reconstructive complications correlate with history of previous surgery · Medical complications correlate with ASA status and age


After oral/oropharyngeal reconstruction: · Good to moderate speech quality is achieved by 96 % of patients · Prognosis of swallowing is more guarded, with 19 % of patients needing long-term tube feeds · Early postoperative aspiration is associated with resection of more than half of the tongue base and preoperative radiation therapy


Thank you for your attention!

Salsipuedas, Baja California




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