Учебники / Operative Techniques in Laryngology Rosen 2008

190	Laser Treatment for Subglottic Stenosis

■Absolute contraindications for endoscopic treatment of stenosis include airway narrowing due to external compression and tracheomalacia/cartilage collapse of the airway

■Relative contraindications for endoscopic treatment of airway stenosis include extensive length of stenosis (greater than 2–3 cm in length), complete stenosis (no identifiable lumen), and stenosis at the level of the tracheostomy.

■“Mapping” of the stenosis is an important part of the initial evaluation of airway stenosis, and is helpful for determining treatment planning.

■The CO2 laser is generally the workhorse laser for endoscopic airway management.

■Laser radial incisions are used to open the stenosis, while simultaneously preserving surrounding mucosa for re-epithelialization.

■Topical application of mitomycin C after endoscopic treatment greatly increases the chance for success.

 

■Placement of a T-tube stent represents a intermediate step between pure endoscopic treatment and open procedures for laryngotracheal stenosis.

■A good indicator of successful T-tube placement is the ability of the patient to maintain good air exchange with the T-tube capped at the end of the surgical case.

■Careful follow-up for cleaning and inspection of the T-tube in required in the first 2 months after T-tube placement.

Selected Bibliography

1Montgomery WW, Montogomery SK (1990) Manual for use of Montgomery laryngeal, trachea and esophageal prostheses: update 1990. Ann Otol Rhinol Laryngol 99:2–28

2Shapshay SM, Beamis JF, Hybels RL et al (1987) Endoscopic treatment of subglottic and tracheal stenosis by radial laser incisions and dilation. Ann Otol Rhinol Laryngol 96:661–664

29

Chapter 30

Carcinoma of the Vocal Fold	30

30.1Fundamental and Related Chapters

Please see Chaps. 4, 10, and 13 for additional information.

30.2Disease Characteristics and Differential Diagnosis

This chapter discusses the surgical treatment of squamous cell carcinoma of the glottis (T1N0M0). Nonglottic laryngeal sites of cancer and advanced laryngeal cancer disease that spreads from the level of the vocal fold to other sites are not discussed. Vocal fold cancer involves epithelial migration or invasion via malignant transformation into the lamina propria and muscle of the vocal fold.

The most common symptoms associated with vocal fold carcinoma include hoarseness, change in pitch, and roughness of the voice. For most patients with early vocal fold carcinoma (Fig. 30.1), the more advanced head and neck cancer related symptoms of odynophagia, otalgia, neck mass, or dysphagia are rarely present. Early vocal fold carcinoma can occur unilaterally (T1aN0M0) or bilaterally (T1bN0M0). The specific anatomic sites of the vocal fold that are important to take into consideration when assessing early vocal fold carcinoma include the anterior commissure, laryngeal ventricle, infraglottis, and the arytenoids. The assessment of early vocal

Fig. 30.1  Early carcinoma of the vocal fold

fold carcinoma prior to surgical excision should ensure that the cancer has not spread laterally into the ventricle, the infraglottis, or the supraglottis. The spread of the cancer to the anterior or medial border of the arytenoid cartilage is somewhat controversial regarding resectability via a microlaryngoscopy approach. Normal vocal fold motion must be assured to confirmed early glottic disease.

The most common method for excision of early vocal fold carcinoma is using the CO2 laser via a microlaryngoscopy approach. Cold-steel excision can also be used either in combination with CO2 laser or exclusively, depending on the location and depth of the cancer. The CO2 laser has the advantage of precision, small spot size and its hemostatic properties for excision of the vocal fold cancer. A cold-steel excision is best suited for relatively superficial lesions that have neither deep muscle involvement nor cartilage involvement (arytenoid).

Differential diagnosis of early vocal fold carcinoma is:

■Hyperkeratosis/dysplasia

■Carcinoma in situ

■Recurrent Respiratory Papillomatosis

■Verrucous carcinoma

■Spindle cell carcinoma

■Tuberculosis

■Fungal disease (histoplasmosis, blastomyocosis)

30.3Surgical Indications and Contraindications

Indications for surgery include T1aN0M0 SCCa of the vocal fold.

Contraindications include:

■Inadequate microlaryngoscopic exposure of the entire vocal fold lesion

■T2N0M0 staging with > 5-mm supraglottic or intraglottic extension, partial vocal fold fixation, or arytenoid involvement (note: patient counseling must include the treatment option of radiation therapy).

30.4Surgical Equipment

Equipment needed includes:

■Standard laser microlaryngoscopy set (Chap. 13)

■Tongue blade with fine gauge needles

192	Carcinoma of the Vocal Fold

30

Fig. 30.2  Vocal fold cancer seen via microlaryngoscopy with CO2 laser created marks for proposed excision boundaries (anterior, posterior, and lateral)

30.5Surgical Procedure

1.Exposure of vocal fold cancer via suspension microlaryngoscopy should allow complete visualization of the lesion.

2.Detailed and angled visualization with telescopes, specifically, 30 and 70° telescopes, is essential. Using this method, it is very important to evaluate the borders of the vocal fold cancer from an anterior–posterior, lateral, and infraglottic perspective.

3.Implement all laser safety procedures including protection of the endotracheal tube cuff, patient head and neck protection, and eye protection for all individuals in the OR (see Chap. 13, “Principles of Laser Microlaryngoscopy”).

4.With vocal fold palpation, a decision should be made between using the CO2 laser and cold-steel excision.

5.Using the CO2 laser on a single-fire setting, outline the area of excision anteriorly, posteriorly and laterally around the vocal fold cancer with approximately 1- to 2-mm margins of excision (Fig. 30.2).

6.Using the CO2 laser on a repeat superpulse mode with a relatively small spot size (approximately 0.3 mm), incisions can be made around the vocal fold cancer in an anterior, lateral, and posterior dimension. Care should be taken to make these initial cuts perpendicular to the superior surface of the vocal fold, without any medial or lateral “skiving” of the incisions. Also, it is best to incise the anterior, posterior and lateral excision borders in a fairly

 

even fashion (similar depth) for best exposure during the excision (Fig. 30.3).

7.Complete the anterior, posterior, and lateral borders of the excision down to the appropriate depth that will allow complete excision of the cancer without excessive removal of normal deep laryngeal tissue. Once the anterior, posterior and lateral borders of the excision are completed, the cancer excision can be retracted with a triangular forceps or curved alligator medially for exposure of the inferior border for excision.

8.Prior to the release of inferior excision, it is important to make a mental note of the exact location of the retraction instrument on the specimen, specifically, which border and where on the border the instrument is. This is very helpful for the orientation of the cancer excision immediately after the release of the inferior attachment of the excision (Fig. 30.3).

9.With the cancer excision specimen retracted medially, straight-up scissors or the laser can be used to release the inferior border of the excision and remove the lesion for orientation (Fig. 30.3). This lesion can be placed on a tongue blade and fixed into position with anatomic orientation. The deep margin of the excision lays on the surface of the tongue blade and then the anterior, lateral, and posterior borders of the excision are noted on the tongue blade. Small-gauge pins are used to secure the excision specimen to the tongue blade (Fig. 30.4). It is best to physically review the preoperative cancer excision photographs and the tongue blade orientation with the pathologist immediately after the excision in the operating room. Serial sectioning (using routine histopathology processes) can be used to map the nature of the pathology throughout the specimen and especially at the margins.

10.Carefully evaluate the margins of the excision via highpower microlaryngoscopy and the angled telescopes, looking for other areas of abnormal epithelium or tissue that would require biopsy or further excision.

11.Microcup forceps can be used to take selected margins (lateral, anterior, posterior, inferior, deep) as indicated. These can be sent for frozen section analysis or permanent pathological evaluation. Frozen section processing of the excisional tissue is generally avoided due to inherent inaccuracies in determining margins in a small specimen, especially with laser artifacts.

30.6Postoperative Care and Complications

Immediately postoperatively:

■Same-day surgery discharge on an outpatient basis is typical for this type of vocal fold cancer excision.

■No voice rest indicated.

■Laryngopharyngeal reflux treatment with PPIs may reduce granuloma formation at the operative site.

■Follow-up with patient, depending on the results of the final pathology report

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Fig. 30.4  Orientation and pinned vocal fold cancer excision specimen on tongue blade

Fig. 30.3  Medial retraction of vocal fold cancer excision with exposure of the inferior border for excision (with scissors in place for final excision)

Complications include:

■Bleeding from the deep excision location

■This can be treated with an application of topical epi-

nephrine on a Cottonoid and/or using the CO2 laser with a defocused beam for coagulation purposes.

■Granulation tissue at operative site

■This granulation tissue commonly occurs within 2–4 weeks and will slowly involute over time. If the granulation tissue is slow to involute, causing significant dysphonia or breathing problems, then this can be re-excised either in the operating room or in an office-based setting.

■Residual tumor/recurrence

Key Points

■Exposure is essential to successful microlaryngoscopy excision of vocal fold carcinoma.

■Orientation of the excision specimen on a tongue blade is extremely helpful to further management of any positive margins that occur on the final pathologic analysis and to minimize the amount of tissue that is damaged or removed during the treatment of early vocal fold carcinoma.

Selected Bibliography

1Myers EN, Wagner RL, Johnson JT (1993) Microlaryngoscopic surgery for T1 glottic lesions: a cost effective option. Ann Otol Rhinol Laryngol 103:28–30

2Zeitels SM (1993) Microflap excisional biopsy for atypia and microinvasive glottic cancer. Operat Tech Otolaryngol Head Neck Surg 4:218–222

3Zeitels SM (1995) Premalignant epithelium and microinvasive cancer of the vocal fold: the evolution of phonomicrosurgical management. Laryngoscope 105(Pt. 2):1–51

4Zeitels SM, Hillman RE, Franco RA, Bunting GW (2002) Voice and treatment outcome from phonosurgical management of early glottic cancer. Ann Otol Rhinol Laryngol 190(Suppl.):3–20

Part B Phonomicrosurgery

for Benign Laryngeal

Pathology

IV Laryngeal Injection

Techniques

Chapter 31
Vocal Fold Augmentation	31
via Direct Microlaryngoscopy

31.1Fundamental and Related Chapters

Please see Chaps. 5, 8, 10, 14, 32, 33, and 34 for further information.

31.2Disease Characteristics

Vocal fold injection can be an extremely useful treatment method for a variety of voice disorders. There are different locations, injection materials and methods to perform vocal fold injection (see Chap. 14, “Principles of Vocal Fold Augmentation”). The advantage of injection augmentation versus open laryngeal procedures (laryngeal framework surgery) is the endoscopic and minimally invasive nature. Other advantages include a more direct visualization of the vocal fold pathology requiring treatment.

Injection augmentation can be divided into two specific anatomic locations, with subsequent different indications, materials, and methodologies applied to all of these locations. A superficial or medial vocal fold injection is performed for the treatment of vocal fold scarring or focal loss of lamina propria.

Fig. 31.1  Deep vocal fold augmentation locations

This technique is discussed in Chap. 32, “Superficial Vocal Fold Augmentation via Microlaryngoscopy.”

Injection augmentation can also be carried out in a deep or lateral vocal fold position. This injection location is used to augment globally the vocal fold for cases of significant glottal incompetence due to:

■Vocal fold paralysis

■Vocal fold paresis

■Vocal fold atrophy

■Sulcus vocalis

■Severe vocal fold scar

■Soft tissue loss of the vocal fold(s)

31.2.1 Material Selection

The ideal vocal fold injection material would be readily available, inexpensive, easy to use and completely biocompatible. The search for such a material has been ongoing for close to a 100 years, and significant advances in vocal fold injection material availability and design have occurred in the last 10 years. The original injection material was paraffin, which resulted in a significant foreign body response and rejection. Similar responses have occurred with Silicone injections as well as more recently with Teflon® vocal fold injections. An additional requirement of all future vocal fold injection materials will be a matching of the biomechanical properties of the material with the biomechanical properties of either the superficial aspect of the vocal fold (superficial layer of the lamina propria) or the deep aspect of the vocal fold (vocalis, thyro-arytenoid and lateral cricoarytenoid muscle).

The materials presently available for vocal fold injection include (see Chap. 14, “Principles of Vocal Fold Augmentation”):

■Autologous® fat

■Radiesse (calcium hydroxylapatite)

■Teflon

■Gelfoam®

■Radiesse Voice Gel®

■Bovine collagen–based products (Zyplast®, Zyderm®)

■Human collagen–based®products (Cymetra®, Cosmoplast , Cosmoderm)

■Hyaluronic acid–based products

(Hyalaform®, Hyalaform Plus®, Restylane®, Perlane®)

■Autologous fascia (minced)

198	VF Augmentation – Microlaryngoscopy

All of these materials other than Cymetra and other collagenbased produces have been designed and used for deep vocal 31 fold augmentation. Bovine collagen, autologous collagen, and human-based collagen are all products that have been used in the past or are presently being used for superficial vocal fold augmentation (see Chap. 32, “Superficial Vocal Fold Augmen-

tation via Microlaryngoscopy”).

31.3Surgical Indications and Contraindications

Vocal fold augmentation is indicated for the patient with glottal incompetence; however, the degree, nature, and cause of the glottal incompetence need to be further elucidated. Incomplete vocal fold closure is divided into global or focal deficit of the vocal fold. Furthermore, the nature of the glottal incompetence can be identified as to either a lack of muscle bulk or of lamina propria (or both). For disorders that cause global glottal incompetence and/or lack of vocal fold bulk such as vocal fold paralysis, vocal paresis, and vocal fold atrophy, a deep vocal fold augmentation is the preferred injection approach.

Prior to vocal fold augmentation, careful evaluation and consideration of the patient’s airway is warranted. Patients with poor abductory range of motion on the contralateral vocal fold or with poor bilateral vocal fold abduction are at significant risk for airway compromise postoperatively. This contraindication is especially true for vocal fold lipoinjection, which requires significant overinjection of the vocal fold (see Chap. 14, “Principles of Vocal Fold Augmentation”).

31.4Surgical Equipment

Vocal fold augmentation via microlaryngoscopy requires following:

■Standard phonomicrosurgery equipment (see Chap. 10)

■Vocal fold injection needle and device

Lipoinjection of the vocal fold requires:

■Standard phonomicrosurgery set (See Chap. 10)

■Brunings syringe vocal fold injection device with 18and 19-g needles (Storz, St. Louis, Mo.) or Instrumentarium lipoinjection device (Instrumentarium Surgical Corp., Inc., Montreal, Quebec, Canada).

■Liposuction device (large bore, low pressure) (Tulip™) or small “plastics” instrument tray for open harvest

■Sterile funnel

■Merocel™ sponges (Medtronic-Xomed, Jacksonville, Fla.)

Endoscopic vocal fold injection requires the following:

■Slotted small laryngoscope (anterior commissure laryngoscope; Pilling, Fort Washington, Pa.)

 

■Vocal fold injection needle and device

■Zero degree Hopkins telescope (4–5 millimeters in diameter and 30 cm long)

■C-mount camera and video monitor

31.5Surgical Procedure

Selection of the vocal fold augmentation technique is determined by the underlying etiology, the vocal fold injection location, comfort level of the surgeon, and the vocal fold injection material. The options for vocal fold injection methodology include percutaneous, transoral, endoscopic direct laryngoscopy, and via microlaryngoscopy (see Chaps. 33, “Peroral Vocal Fold Augmentation in the Clinic Setting” and 34, “Percutaneous Vocal Fold Augmentation in the Clinic Setting”).

31.5.1Principles of Deep Vocal Fold Augmentation

Principles of deep vocal fold augmentation comprise the following:

1.The vocal fold should be injected at the intersection of two anatomic landmarks:

a)At the level of the vocal process

b)At the transition zone from the superior surface of the vocal fold to the ventricle (superior arcuate line). The junction of these two anatomical locations is the optimal location for a deep vocal fold injection (Fig. 31.1).

2.The vocal fold injection needle should be angled slightly laterally and placed approximately 3–5 millimeters deep to the mucosa prior to the injection. Injection can then be done in a graded or step-wise fashion, observing the immediate impact of the vocal fold injection on vocal fold size, bulk, position, and glottic closure. Optimal needle placement is confirmed when the initial augmentation is seen at the level of the infraglottis. After reasonable infraglottic augmentation, further injection will often spread superiorly to augment the vocal fold at the level of the glottis or the injection needle can be withdrawn 1–2 mm to finish the vocal fold augmentation in the region of the midmembranous vocal fold (Fig. 31.2).

3.Often, a second injection site is required along the superior arcuate line in the region of the midmembranous vocal fold (Fig. 31.1).

4.It is important to remember that the best deep vocal fold injection is placed lateral within vocal fold, and this is optimally achieved with a slightly angled injection needle that is not completely parallel to the longitudinal axis of the laryngoscope (thus the advantage of using a slotted laryngoscope). This can be further enhanced by purposefully positioning the laryngoscope to visualize the lateral aspect of the vocal fold ventricle as opposed to the midline of the glottis.

 

31.5.2Vocal Fold Augmentation via Microlaryngoscopy

Suspension microlaryngoscopy with general anesthesia can be used to perform vocal fold augmentation. The advantages of this approach are outstanding visualization and precise vocal fold injection placement. The disadvantage is the lack of an endpoint due to the inability to assess vocal fold closure.

1.Review of the preoperative videolaryngoscopy and/or videostroboscopy is an important start to vocal fold augmentation.

2.After adequate general anesthesia and complete muscle relaxation has been achieved by the anesthesiology team, a large bore laryngoscope is suspended, providing complete visualization of the vocal fold (see Chap. 10, “Principles of Phonomicrosurgery”).

3.Angled telescopes (0, 30, and 70°) are used to visualize the entire larynx in a “three-dimensional fashion,” which allows one to fully assess the lack of bulk and exact pathology that is to be corrected with the vocal fold augmentation (see Chap. 10).

4.Deep vocal fold augmentation should be performed at this vocal fold injection site approximately 3–5 mm deep to the mucosa, and the needle should be angled as lateral as possible as it is placed through the laryngoscope. To ensure a lateral vocal fold injection site, it is wise to position the laryngoscope with the suspension device angled in a lateral facing direction (Fig. 31.3).

5.Visualization of the vocal fold during the vocal fold injection allows one to determine the ideal amount and location of the injection by observing immediate changes in the vocal fold contour during and after the injection.

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6.Over-correction as depicted on Fig. 31.7 should be achieved.

7.Lidocaine is sprayed on the larynx after the vocal fold injection is completed to help prevent postoperative laryngospasm.

31.5.3Endoscopic Vocal Fold Injection

Endoscopic vocal fold injection is used for a deep vocal fold augmentation. This technique allows the surgeon a magnified, detailed view during vocal fold augmentation, with the patient awake. This allows visualization of vocal fold motion and closure before, during, and after the injection. This injection technique is also advantageous given that it allows the vocal fold injection to be performed with complete visualization of the procedure by both student and mentor simultaneously. Endoscopic vocal fold injection involves a deep vocal fold augmentation using a small slotted laryngoscope under a local anesthesia (with minimal intravenous sedation). A surgical telescope provides endoscopic visualization for the procedure.

1.Preoperative anesthesia is a crucial aspect of this procedure. Topical nebulized 4% plain lidocaine should be administered for 10–15 min prior to the operative procedure. Additional 4% plain lidocaine can be directly applied to the oropharynx and endolarynx via indirect laryngoscopy and/or direct laryngoscopy. Alternative anesthesia methods include trans-tracheal lidocaine injection and/or superior laryngeal nerve block (either percutaneous or via the pyriform sinus).

2.Preoperative anesthesia will allow the slotted anterior commissure laryngoscope (Pilling) to be passed through the

Fig. 31.2  Depth of injection needle for deep vocal fold augmentation	Fig. 31.3  Angled laryngoscope position for deep vocal fold augmenta-
	tion via microlaryngoscopy

200	VF Augmentation – Microlaryngoscopy

oral cavity and oropharynx and to pick up the tip of the epiglottis. With this visualization, 4% plain lidocaine can be 31 applied directly to the endolaryngeal region and intended

vocal fold.

3.After adequate laryngeal anesthesia is achieved and a small amount of intravenous sedation is given, the slotted laryngoscope is then advanced with the nondominant hand, immediately over the vocal fold to be injected and manually suspended. The laryngoscope is positioned to slightly retract the false vocal fold to allow complete visualization of the entire length of the membranous vocal fold and the ventricle of the intended site for injection.

Fig. 31.4  Overview of endoscopic vocal fold injection

Fig. 31.5  Endoscopic vocal fold injection method

 

4.A 0° telescope (30 cm, 4- to 5-mm diameter) is then passed through the manually suspended laryngoscope. The vocal fold motion, closure pattern, and the glottal incompetence deficit are noted by visualization through either the endoscope or a camera attached to the endoscope (Fig. 31.4).

5.The injection device is then passed into the laryngoscope parallel with the endoscope, using the visualization achieved by the endoscope for guidance. Deep vocal fold injection is performed (Figs. 31.5, 31.6).

6.Once adequate vocal fold augmentation is obtained by direct visualization (Fig. 31.7), the needle can be retracted and kept sheathed within the laryngoscope, and vocal fold closure is visualized during the patient’s phonation. The need for any further injection is determined.

31.5.4Lipoinjection of the Vocal Fold

Lipoinjection of the vocal fold is designed to be a deep/lateral vocal fold injection, resulting in medialization and augmentation of the vocal fold by deposition of autologous fat. Lipoinjection can be done via an endoscopically guided peroral approach or a microlaryngoscopy approach (see above). Given the viscous nature of the fat, a pressurized injection device such as a Brunings syringe or the lipoinjection device designed by Instrumentarium is required. Fat harvest for lipoinjection can be done either through open incision with harvesting subcutaneous fat or via liposuction. Liposuction is the preferred technique because it is expedient, less invasive, and provides perfectly sized injection material. For patients with only “modest” amounts of subcutaneous fat, open harvest is recommended. The most reasonable location for open harvest is in the in- fra-umbilical region or through a preexisting abdominal scar. The former area of the body typically has a plentiful amount of material and an incision immediately inside the umbilicus can be easily hidden. Fat harvest can be done under local or general anesthesia.

1.Open fat harvest

a)The abdomen is prepped and draped in a sterile fashion.

b)Local injection of lidocaine with epinephrine is done as a regional block for local anesthesia, or only at the proposed incision site for hemostasis if under general anesthesia.

c)A curvilinear incision is made at the junction of the umbilicus and the infra-umbilical region, from approximately 4 to 8 o’clock.

d)Subcutaneous elevation of the dermis proceeds in an inferior direction, releasing the subcutaneous fat off the subdermal plane.

e)The fat is sharply dissected out with cold-steel instruments, taking care not to violate the skin above or the peritoneum below.

f)Hemostatis is attained with electric cautery as needed, and tacking sutures are placed in the deeper aspect of the wound to the subdermal plane.

g)The harvested fat is then carefully cut into small pieces with scissors, approximately 1 × 2 × 1 mm in size. (This aspect of the procedure is time consuming and laborious

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but important. If the fat graft is not properly prepared, then it will not flow smoothly through the injection needle.)

h)The fat graft material is then handled in a similar manner as the liposuction harvest material (described below).

2.Liposuction fat harvest for lipoinjection

Liposuction should be performed using a large bore, lowpressure liposuction technique. Small-gauge and high-pres- sure liposuction devices should be avoided to minimize

trauma to the fat during the harvest process. An excellent liposuction cannula is made by Tulip™ (San Diego, Calif.) that includes a 4.6-mm diameter, single-hole liposuction cannula with low-pressure suction applied to the cannula. Liposuction from the subcutaneous abdominal space can be done under general or local anesthesia. The latter requires local anesthesia injection in the area of the intended liposuction.

a)The abdominal skin is prepped and draped in a sterile fashion.

b)A small skin incision (approximately 5 mm) is made in the right upper quadrant of the abdomen.

c)The liposuction cannula is passed through the skin and into the subcutaneous space, and negative pressure is applied to the liposuction cannula.

d)The liposuction cannula is then moved rapidly in the subcutaneous space in a transverse direction across the patient’s abdomen, with great care taken to control the plane and location of the liposuction tip to avoid penetration into the peritoneum or the overlying skin. Pinching the skin to create “tunnels” helps develop a safe plane for fat harvest (Fig. 31.8).

3.Preparation of fat for lipoinjection

Fat harvested by any method is covered with free fatty acids, blood, and serum. The free fatty acids are from ruptured lipocytes and induce an intense inflammatory response if not removed prior to lipoinjection. This inflammatory response will diminish the graft survival. The fat must be carefully and thoroughly rinsed and carefully handled prior to lipoinjection to maximize graft survival.

a)Fat from either open or liposuction harvest is placed in a sterile funnel that is lined with strips of Merocel (Fig. 31.9).

b)Suction tubing is applied to the downward spout of the funnel, and 2 liters of saline is used to rinse and irrigate the blood and fatty acids from the surface of the harvested fat.

c)The fat is then transferred into a small dish with 100 U of regular insulin and soaked for 5 min (the insulin is theorized to stabilize the lipocyte cell membranes and thus improve cell survival during the transplantation process).

d)To remove excess moisture, the fat is then placed on a dry Merocel sponge and partially dried by air for several minutes.

e)The harvested material can then be loaded into the injection device in preparation for lipoinjection (Fig. 31.10).

4.Lipoinjection of the vocal fold

The approach and exposure of the vocal fold and injection sites for Lipoinjection of the vocal folds are identical to all

Fig. 31.6  Endoscopic vocal fold injection method

Fig. 31.7  Photo demonstrating the appropriate amount of overcorrection (15–30%, or an additional 0.1–0.2 ml of material) used for most injectables

previously described deep vocal fold injection techniques (see above). Great care should be taken to avoid injection of fat material into the:

a)Ventricle

b)Subglottis

c)Superficial planes of the lamina propria

Lipoinjection of the vocal fold should be performed with the goal of substantial overinjection of the vocal fold to allow for expected fat loss during the transplantation

process (Fig. 31.11).

Care should be taken to restrict lipoinjection unilaterally if the patient has vocal fold paralysis and poor abduction of the contralateral vocal fold. More aggressive lipoinjection can be carried out safely when both vocal folds are mobile. Often, bilateral lipoinjection patients with mobile vocal folds will be done to the extent that after immediate completion of the procedure the membranous vocal folds will be in complete approximation.