Abstract The present prospective study was designed toanalyze the results achieved with intracordal autologous fatinjection for aspiration in a series of 20 patients with re-current laryngeal nerve paralysis. Swallowing was docu-mented by having each patient swallow puréed food col-ored with methylene blue during nasofibroscopy. No la-ryngeal adverse effects were associated with the intracordalinjection of fat. One patient developed an abdominal hema-toma at the donor site. The intracordal injection of autolo-gous fat after 1 year resulted in an 85% successful reha-bilitation of swallowing. One of the three patients whofailed the initial rehabilitation of swallowing was managedsuccessfully with reinjection of autologous fat, resultingin a 90% definitive successful rehabilitation of swallow-ing. In all patients, speech and voice were immediately im-proved after the intracordal injection of autologous fat. Ob-jective acoustic recordings documented the improvementin selected speech and voice parameters when comparedwith pretreatment data. Our presented experience showsthat the intracordal autologous fat injection is a safe andvaluable treatment option in patients with aspiration afterrecurrent laryngeal nerve paralysis.

Key words Recurrent laryngeal nerve paralysis · Aspiration · Intracordal fat injection

Introduction

Thyroid surgery, malignancies, trauma and neurologic dis-eases are considered to be the main causes for recurrentlaryngeal nerve paralysis [15]. In patients with such nerveparalysis, the major clinical complaint is a breathy and weakvoice. However, the incomplete glottic closure can also

result in aspiration and cough with the risk of developingpneumonia from aspiration [11, 15].

To our knowledge, Mikaelian et al. [8] were the first toreport the use of autologous fat for intracordal injectionsin patients with a recurrent laryngeal nerve paralysis. Sincethen various animal, clinical, radiological and pathologicalstudies have documented fat survival once transplantedwithin a paralyzed true vocal cord [2, 4, 5, 7, 9, 13, 14,17]. However, to our knowledge, no report has specifi-cally studied the outcome after intracordal autologous fatinjection in patients with aspiration due to recurrent nerveparalysis. The present prospective study was therefore de-signed to analyze the course of swallowing, speech andvoice in a series of 20 patients with aspiration followingsuch nerve paralysis consecutively managed at our depart-ment with intracordal injections of autologous fat.

Materials and methods

Twenty consecutive patients with aspiration related to recurrent la-ryngeal nerve paralysis and referred to the Department of Otrhino-laryngology, Laënnec Hospital, between 1996 and 1997 took partin the present prospective study. There were 13 men and 7 women,with ages ranging from 26 to 81 years (mean age, 59 years).Thecauses of the recurrent laryngeal nerve paralysis were pulmonaryresection and mediastinal lymph-node dissection for lung carcinoma(n = 11), resection of an intramediastinal malignancy (n = 3), thy-roid surgery (n = 2), unresectable esophageal carcinoma (n = 1),base of skull surgery for cholesteatoma (n = 1), and radical neckdisection with transection of the left Xth cranial nerve (n = 1). Inthe last patient, the cause of the nerve paralysis was unknown. Twoof the patients in our series had complete vagal nerve paralysis (oneof them had transection of the nerve in the neck).

The severity of aspiration varied, using the scale described byPearson [10] in the present series. Fourteen patients had grade 2 as-pirations and had laryngeal penetration at the time of swallowingdocumented in these 14 patients by swallows of puréed food col-ored with methylene blue during fiberoptic nasofibroscopy [16]. Theremaining six patients had grade 3 aspirations [10] with pulmonarycomplications and required nasogastric tube insertion (n = 3), gas-trostomy (n = 1), jejunostomy (n = 1) and nasogastric tube insertionwith assisted ventilation (n = 1). Breathy hypophonia was noted in16 patients. Self-assessments of voice quality by each patient re-vealed that the dysphonia was considered to be severe in 16 patients,and moderate in 4.

O. Laccourreye · R. Paczona · M. Ageel · S. Hans ·D. Brasnu · L. Crevier-Buchman

Intracordal autologous fat injection for aspiration after recurrent laryngeal nerve paralysis

Eur Arch Otorhinolaryngol (1999) 256 :458–461 © Springer-Verlag 1999

Received: 27 October 1998 / Accepted: 4 March 1999

LARYNGOLOGY

O. Laccourreye (Y) · R. Paczona · M. Ageel · S. Hans ·D. Brasnu · L. Crevier-BuchmanDepartment of Otorhinolaryngology – Head and Neck Surgery, Laënnec Hospital, Assistance Publique Hôpitaux de Paris, University of Paris V, 42 Rue de Sèvres, F-75007 Paris, France

Under general anesthesia with endotracheal intubation, fat wasobtained from the lower abdomen under strict asepsis by a 15 Flipectomy canula connected to an aspirator system under 1 atm ofnegative pressure in 19 patients, while a surgical incision was re-quired in 1 patient. The harvested fat and fluid were deposited ontoa sterile piece of fine mesh gauze covering a container. Once thefluid had drained, the fat was placed into the barrel of a Bruningsyringe with an attached 19-gauge needle. A laryngoscope was thenused to expose the larynx. The autologous fat was injected transo-rally into the paralyzed thyroaytenoid muscle. The point of injec-tion was located lateral to the vocal process of the arytenoid carti-lage and the injection was continued until rotation of the arytenoidcartilage and convex bowing of the paralyzed vocal cord wasachieved (resulting in an approximative 50% overcorrection pastmidline). In all patients a whole barrel of the Bruning syringe wasinjected, resulting in the injection of 3–4 cc of autologous fat. Thelaryngoscope was removed and the patient was immediately extu-bated.

All patients were followed for a minimum of 12 months or un-til death. Swallowing was documented by having the methylene bluepurée swallow [16] performed at 3, 6 and 12 months after the in-jection. Recurrence of aspiration was defined as coughing at thetime of swallowing and/or the presence of laryngeal penetration du-rung the fiber nasofibroscopy. Objective evaluation of speech andvoice relied upon acoustic recordings using the Computerized SpeechLab and the Multidimensional Voice Program (Kay Elemetrics,Pine Brook, N.J., USA) performed prior to the injection and at 3,6, and 12 months after the injection. Parameters recorded were themaximum phonation time, speech rate and phrase grouping. Themaximum phonation time was defined as the best attempt in sec-onds to prolong the vowel /a/ maximally at a comfortable intensity.The speech rate was defined as the number of words read perminute. The phrase grouping was defined as the number of wordsper breath of air charges. The frequency parameters recorded werethe average fundamental frequency (Fo), jitter (cycle to cycle vari-ation in Fo), shimmer (cycle to cycle variation in amplitude), andnoise-to-harmonics ratio. Statistical comparison of the acousticalrecordings was performed using the non-parametric Wilcoxon T-test and Friedman test. Statistical significance was set at the 0.05 level.

Results

No patient experienced postinjection laryngeal complica-tions. The only complication at the donor site was a sub-cutaneous hematoma in one patient, but this patient wasthe only one who did not have a pressure dressing appliedat the donor site after harvesting the autologous fat. Elevenpatients in our series died before the 12th postinjectionmonth. The causes of death were progression of the malig-nancy in 10 patients (lung carcinoma in seven patients), anda hemothorax noted 1 month after pneumonectomy for lungcarcinoma in one patient.

Evaluation of swallowing

Immediate successful rehabilitation of normal swallowingwithout laryngeal penetration of puréed food or secretionswas achieved in 17/20 patients (85%).

Removal of feeding tubes and normal swallowing with-out laryngeal penetration were achieved in five of the six pa-tients with grade 3 aspiration. The only patient with grade 3aspiration in whom normal swallowing was not reestab-lished had transection of the vagus nerve at the neck. In this

patient, a secondary cricopharyngeal myotomy resulted ina transient improvement of swallowing, but persistent la-ryngeal aspiration of liquids led to the maintenance of agastrostomy feeding tube. Within the group of 14 patientswith grade 2 aspirations, 2 patients had recurrence of laryn-geal aspiration after a transient improvement of swallow-ing. One patient refused any further treatment as laryngealpenetration was asymptomatic.The other patient was man-aged successfully with a secondary intracordal injection ofautologous fat. Therefore, an overall 90% success rate interms of swallowing rehabilitation was achieved in thepresent series.

Evaluation of speech and voice

Breathy hypophonia improved within the day followingthe intracordal injection, and all patients who had prior lungsurgery immediately recovered an effective cough. Four pa-tients in our series reported a secondary degradation ofphonation (Table 1). As depicted in Table 1, the mean valueof the maximum phonation time, speech rate, and phrasegrouping 3 months after the intracordal injection of autol-ogous fat was significantly improved when compared withthe preinjection data. The analysis of the evolution of theacoustic parameters after the intracordal injection of au-tologous fat did not reveal any significant statistical dif-ference (Table 2).

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Table 1 Comparison of acoustic parameters before and after theintracordal injection of autologous fat with the non parametricWilcoxon T test (NS: P value > 0.05 not significant)

Acoustic parameters Preinjection 3 months Ppost-injection value

Maximum phonation time (s)Mean 4 6 0.025Range 3–7 3–13

Speech rate (wpm)Mean 114 145 0.025Range 88–169 130–169

Phrase groupingMean 7 15 0.005Range 5–18 9–27

Average F0 (Hz)Mean 156.9 166.2 NSRange 78.9–269.2 112.5–244.2

Jitter (%)Mean 3.54 1.06 NSRange 0.61–17.1 0.2–10.3

Shimmer (%)Mean 6.4 6.7 NSRange 2.66–20.9 1.8–10.3

Noise-to-harmonics ratioMean 0.16 0.15 NSRange 0.1–0.8 0.11–0.44

Discussion

The injection laryngoplasty was introduced by Arnold [1]to palliate the consequences of a unilateral recurrent la-ryngeal nerve paralysis and initially relied on the intra-cordal injection of Teflon. The disadvantages of Teflon in-cluded irreversibility, lack of adjustability as well as the riskfor extrusion, migration, foreign-body reaction and inducedgranuloma [3]. Such disadvantages subsequently led tothe use of gelfoam and injectable collagen [3, 6, 12]. How-ever, gelfoam provides only a short-term temporary im-provement [3]. Similarly, a 20%–30% regression of re-sults has been reported with collagen due to the unpre-dictible degree of resorption of this material [12]. Withthe recent increase of Creuzfeldt-Jacob’s disease in Eu-rope due to the surgical use of bovine collagen-based ma-terials, we decided at our department not to use collagenimplants and instead turned to autologous fat when per-forming intracordal injections to treat the consequences ofunilateral inferior laryngeal nerve paralysis.

In the present series, no patients experienced postinjec-tion laryngeal complications when managed with an intra-cordal injections of autologous fat. Such data confirm thesafety of the intracordal injection of autologous fat in pa-tients with unilateral recurrent laryngeal nerve paralysis, asreported previously [3–5, 7–9, 12, 17]. In all patients inour series, speech and voice were immediately improvedafter the intracordal injection of autologous fat. Our ob-jective acoustic evaluation confirmed the benefit of the in-tracordal injection of speech and voice, as the mean valueof the maximum phonation time, group phrasing and speech

rate were improved 3 months after the intracordal injec-tion of autologous fat when compared with the preinjectiondata (Table 1). Such data demonstrate that the intracordalinjection of autologous fat allows for a better glottic com-petency in patients with recurrent laryngeal nerve paralysis.

Numerous evidence exists documenting the survival ofinjected boluses of autologous fat within a paralyzed thy-roarytenoid muscle. Brandenburg et al. [5] used magneticresonance imaging to provide evidence that fat could sur-vive transplantation into the vocal cord as long as 31 monthsafter injection. Bauer et al. [2], and Shaw et al. [13] re-ported two human pathological cases demonstrating per-sistent fat graft within the thyroarytenoid muscle 5 and 18 months, respectively, after injection. Our findings thatspeech and voice parameters did not statistically vary from 3 to 12 months after the intracordal injection of autologousfat (Table 2) show that fat can survive once transplantedwithin the paralyzed thyroarytenoid muscle. Such data arein agreement with various studies documenting long-last-ing phonatory results after the intracordal injection of au-tologous fat in patients with unilateral recurrent nerveparalysis [4, 8, 13, 14]. However, four of our patients didexperience a secondary degradation of speech and voice,confirming that the main drawback of the intracordal in-jection of autologous fat is the possible unpredictible de-gree of resorption of this material once injected, leadingall the authors to recommend overcorrection at the time ofinjection to achieve long-lasting improvement.

The results in terms of swallowing were also rewardingas aspiration disappeared within 24 h after the intracordalinjection of the boluses of autologous fat in all but three pa-tients, resulting in a 85% successful rehabilitation of swal-

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Table 2 Evolution of speechand voice parameters after in-tracordal injection of autolo-gous fat analyzed with the non-parametricFriedman test(wpmwords per minute, F0 fundamental frequency)

Acoustic parameters 3 months post- 6 months post- 12 months post-Pinjection injection injection- value

Maximum phonation time (s)Mean 6 10 9 NSRange 3–13 8–14 7–19

Speech rate (wpm)Mean 145 144 141 NSRange 130–169 134–161 130–169

Phrase groupingMean 15 19 21 NSRange 9–27 13–29 16– 27

Average F0 (Hz)Mean 166.2 141.6 142.7 NSRange 112.5–244.2 101–221.4 110.1–238.7

Jitter (%)Mean 1.06 0.65 0.51 NSRange 0.2–10.3 0.2–1.83 0.2–1.21

Shimmer (%)Mean 6.7 3.1 2.8 NSRange 1.8–10.3 1.3–7.4 1.1–8.9

Noise-to-harmonics ratioMean 0.15 0.12 0.13 NSRange 0.11–0.44 0.10–0.16 0.10–0.18

461

lowing. A second intracordal injection of autologous fat inone resulted in an overall rate of 90% successful rehabili-tation of swallowing. In patients with a unilateral recur-rent nerve paralysis after pulmonary resection, incompleteglottic closure and non-efficient cough yields a significantrisk of developing pneumonia from aspiration, whichmight be fatal in this patient population. In such patientsin our series recovery of an effective cough allowed for ef-ficient chest therapy. Although 8 of our patients with a pul-monary maliganacy ultimately died, death was never re-lated to aspiration or the intracordal injection of autologousfat.

References

1.Arnold GE (1962)Vocal rehabilitation of paralytic dysphonia.IX. Technique of intracordal injection. Arch Otolaryngol 76 :358–365

2.Bauer CA, Valentino J, Hoffman HT (1995) Long-term resultsof vocal fold augmentation with autogenous fat. Ann Otol Rhi-nol Laryngol 104 :871–874

3.Benninger MS, Crumley RL, Ford CN, et al (1994) Evaluationand treatment of the unilateral paralyzed vocal fold. Otolaryn-gol Head Neck Surg 111 :497–508

4.Brandenburg JH, Kirkham W, Koschkee D (1992) Vocal cordaugmentation with autogenous fat. Laryngoscope 102 :495–500

5.Brandenburg JH, Unger JM, Koschkee D (1996) Vocal cord in-jection with autogenous fat. A long-term magnetic resonanceimaging evaluation. Laryngoscope 106 :174–180

6.Ford CN, Martin DW, Warner TF (1984) Injectable collagen inrehabilitation. Laryngoscope 94 :513–518

7.Hill DP, Meyers AD, Harris J (1991) Autologous fat injectionfor vocal cord medialization in the canine larynx. Laryngoscope111 :344–348

8.Mikaelian DO, Lowry LD, Sataloff RT (1991) Lipoinjection forunilateral vocal cord paralysis. Laryngoscope 101 :465–468

9.Mikus JL, Koufman JA, Kilpatrick SE (1995) Fate of liposuc-tioned and purified autologous fat injections in the canine vocalfold. Laryngoscope 105 :17–22

10.Pearson BW (1981) Subtotal laryngectomy. Laryngoscope 81 :1904–1912

11.Périé S, Laccourreye O, Bou-Malhab F, Brasnu D (1998) Aspi-ration in unilateral recurrent laryngeal nerve paralysis after sur-gery. Am J Otolaryngol 19 :18–23

12.Remacle M, Dujardin JM, Lawson G (1995) Treatment of vo-cal fold immobility by glutaraldehyde-cross-linked collagen in-jection: long-term results. Ann Otol Rhinol Laryngol 104 :437–441

13.Shaw GY, Szewczyk MA, Searle J, Woodroof J (1997) Autol-ogous fat injection into the vocal folds: technical considerationsand long-term follow-up. Laryngoscope 107 :177–186

14.Shindo ML, Zaretsky LS, Rice DH (1996) Autologous fat injec-tion for unilateral vocal cord paralysis. Ann Otol Rhinol Laryn-gol 105 :602–606

15.Tucker HM (1996) Rehabilitation of the immobile vocal foldparalysis and/or fixation. In: Fried MP (ed) The larynx: a mul-tidisciplinary approach, 2nd edn. Mosby Yearbook, St Louis,pp 209–225

16.Wu CH, Hsiao TY, Chen JC, Chang YC, Lee SY (1997) Eval-uation of swallowing safety with fiberoptic endoscope: compar-ison with videofluoroscopic technique. Laryngoscope 107 :396–401

17.Zaretsky LS, Shindo ML, deTar M, Rice DH (1995) Autologousfat injection for vocal cord analysis: a long-term histologic eval-uation. Ann Otol Rhinol Laryngol 105 :1–4