Airway Complication After Thyroid Surgery: Minimally Invasive Management of Bilateral Recurrent Nerve Injury

Transcription

1 ThP l aryngoscope Lippincott Will iams & Wilkins, Inc., Philadelphia 2000 The Am eri ca n Laryngological, Rhinological a nd Otological Society, Inc. Airway Complication After Thyroid Surgery: Minimally Invasive Management of Bilateral Recurrent Nerve Injury Laszlo Rovo, MD; J ozsef Jori, MD, PhD; Marek Brz6zka, MD; J eno Czigner, MD, DSc Objectives: After bilateral vocal cord paralysis, the consequent para.median position usually necessitates tracheostomy for at least 6 months, when the paralysis is potentially reversible. In the present study a reversible ndoscopic vocal cord laterofixation procedure was used instead of tracheotomy. Study Design: Prospective study of 15 consecutive patients aged 33 to 73 years who suffered bilateral recurrent laryngeal nerve paralysis after thyroid surgery. Methods: The op ration was performed endoscopically with a special endo-extralaryngeal needle carrier instrument. Two ends of a monofilament nonresorbable thread were passed above and under the posterior third of the vocal cord and knotted on the prelaryngeal muscles, permitting the creation of an abducted vocal cord position. If movement of one or both vocal cords recovered, the suture was removed. Regular spirometric measurements and radiological aspiration tests were conducted on the patients. ResuUs: During the follow-up period of S to 40 months, airway stability was demonstrated in all but one patient. After the repeated lateralization procedure, this patient's breathing improved. Partial or complete vocal cord recovery was observed in eight patients. In six patients further voice improvement was achieved when the threads were removed after vocal cord medialization or recovery. Mild postoperative aspirations ceased in the first postoperative days. Conclusions: Tb.is management approach offers an alternative to tracheostomy in the early period of paralysis, avoids terminal loss of voice quality, and provides a "onestage" solution for permanent bilateral recurrent nerve ittjuries. Key Words: Airway complication, recurrent n erve iajury, minimally invasive surgery, vocal cord laterofixation, thyroid surgery. Laryngoscope, 110: , 2000 From the Depa rtments ofotorhinolaryngology, Head and N ck Surgery (L.R., J.J., J.C.) a nd Anesthesiology and Intensive Therapy (M.B.), Albert Sz nt- yllrgyi Medical Univ rsity, Szegcd, Hungary. Supported by the Hungarian Scientific Council (E'IT:l 3- lll/98). Editor's Note: This Manuscript was accepted for publication Octobe r 1, Send Reprint Requests to Laszl6 Rllv6, MD, Department of Otorhinolaryngology, Head and Neck Surgery, A. Szent;..Gylirgyi, Medical University, Tisza L. lot. 111, H-6725 Szeged, Hungary. E-mrul: rov~rl. szote. u -szeged.hu 140 INTRODUCTION Vocal cord paralysis remains a complication of thyroid surgery. 1 2 More than 50% of the paralysis is transienti-3 because intraoperative damage commonly results in reversible neuropraxic injury rather than complete transsection of the recurrent nerve. Although animal experiments h ave demonstrated tha t atrophy of the laryngeal muscles becomes irreversible after 7 months of inactivation,4 clinical observation has shown that it is worth waiting 6 to 12 months for spontan eous recovery of vocal cord function. Bilateral injury most often results from reoperation or operation on malignant tumors The magnitude of the dyspnea depends on the position of the paralyzed vocal cords and on the cardiopulmonary reserve, but often patients cannot be extubated after surgery. According to the literature6, 7 and in our own experience, the common vocal cord lateralization techniques (including arytenoidectomy with or without cordectomy and tra nsverse cordotomy) cause drastic irreversible damage to the larynx and phonation. The long-term success of the theoretically superior reinnervation procedure has been about 80%, but reinnervation requires a delay of 4 to 6 months after surgery before active abduction may begin. 7 Thus most patients must be tracheostomized for 6 to 12 months, with all the possible somatic and psychological side effects. The most significant side effects are intraoperative and postoperative h emorrhage, risk of wound infection, especially wh en immediately after thyroid surgery, and the complications of tracheomalacia and tracheal stenosis due to scarring. Finally, this procedure increases the cost a nd length of hospital stay and ambulatory care. Hence, in cases when suffocation presents only on exertion, the "watch and wait" policy is often preferable to tracheostomy, although this a pproach may restrict the patient's daily activities. Articles were published in the early 1990s about a reversible, simple exo-endolaryngeal suture technique for th e "acute" lateralization of the vocal cord to provide an immediate stable airway for patients with bilateral vocal cord paralysis This method not only eliminated the need for tracheostomy but also afforded a favorable solution in terms of function: if contralateral vocal cord function recovered, the fixed vocal cord could be released. Rov6 et al. : Management of Bilateral Recurrent Nerve Injury

2 Despite promising early results, this concept has not been a ccepted. According to Tucker, 7 the major drawback of this simple procedure is that in ma ny cases it does not yield adequate improvem ent. To solve this problem we suggested 10 inserting the laterofixing suture in cases of early voca l cord lateralization by using a modification of Lichtenberger's endo-extralaryngeal t echnique We found that this procedure provided a stable airway in the critical early period, but no dat a existed on the effect of laterofixation on the vocal cord after recovery or on the procedure's long-term effica cy. We now r eport on our 3-year experience with the r efinement of this technique. PATIENTS AND METHODS Patients Fifteen consecutive patients (14 women and 1 man) were operated on for bilateral vocal cord paralysis within 6 months after thyroid surgery from June 1996 to April 1998 (Table 1). The age of the patients ranged from 33 to 73 years. Follow-up was between 3 and 40 months (mean, 17 mo ). The thyroid surgeries were performed previously in the referring general surgery departments of the Albert Szent-Gyorgyi Medkal University. Two patients had undergone thyroid oper ation for recurrent malignant tumor, three had had reoperation of a benign lesion, and the remaining patients had had subtotal strumectomy for benign diseases of the thyroid (8 patients) and parathyroid (2 patients). The time between the onset of paralysis and the laterofixation procedure ranged from 2 days to 122 days (mean, 23 d). In six cases the patient could not be extubated after the thyroid surgery; four of these patients were reintubated and two were tracheostomized before they were sent for the vocal cord lateralization procedure at our clinic. The other nine patients had moderate to severe stridor at rest and severe stridor on exertion (Fig. la). Among the five patients who had undergone reoperation of the thyroid gland, three had laryngoscopically proved unilateral vocal cord par alysis before reoperation. After receiving accurate information about the possibility of worsening voice quality, all of the patients chose vocal cord laterali zation instead of tracheostomy. Surgical Technique and Postoperative Care The endo-extralaryngeal suture technique was first described by Lichtenberger 11 for laryngeal stenosis. We modified the original method. In our study two surgeons conducted the operation. The procedure was performed under gener al anesthesia (a Rusch tube was introduced for translaryngeal intubation in four patients, trans-stomal intubation was carried out in four patients, and supraglottic low- frequency JET ventilation was carried out in nine patients). A lgeinsasser or Weerda laryngoscope was used to open up the glottic space. After this, the endoscopist passed one end of a monofil ament, nonresorbable thread (#2-0 or O Prolene) under the posterior third of the vocal cord using Li chtenberger's needle carrier instrument. 11 The other end was passed above the vocal cord across Morgagni's ventricle out to the surface of the neck. The thread formed a loop around the voca l process, permitting the creation of an abducted vocal cord position. The level of the abduction-and the postoper ative width of the glottis-could be controlled correctly by the endoscopist, if J ET ventilation was used for the anesthesia or if the patient was intubated trans-stomally. The assistant surgeon made an approxim ately 10-mm-long incision between the two ends of the thread, then pulled back both ends under the skin with a J a11sen hook, and tied a knot above the prelaryngeal muscles (not on the thyroid ala, as origin ally suggested by Ejnell et aj. 9 and Lichtenberger' 1 ). The wound was closed with one or two sutures. The patients received intravenous steroid (methylprednisolone mg twice daily) until the first or second postoperative day. In the next 4 to 5 days aerosol steroid was administer d (beclomethasone 100 µg thr e times da ily). A wide-spectrum antibiotic (cefuroxime mg twice daily) was used in the first 5 postoperative days. TABLE I. Results of Early Laterofixation Procedures. Change of FIV-1 Values (l) Patient Delay of vc Thread Removal No. Sex Age (y) Side of LF LF (d)' Recovery (postop. wk) Follow-up (mo) Preop. Post op. Last" 1 F 35 L M 45 R 15 L (partially) F 51 L 2 lntub. 1.4 L (reap.) 13 3 (died of ICD) F 73 L (died of ICD) F 68 L 2 26 lntub F 71 L 2 26 lntub F 75 R 122 L (partially) 89th F 41 L 5 R 26th 15 lntub F 47 R 22 L 9th F 42 R 8 R 34th F 33 R 10 B 7th F 68 L F 46 L 7 8 Trach F 55 R 68 L 13th F 52 R 47 L 7 Trach LF = laterofixation; VC = vocal cord; FIV-1 = forced inspiratory volume on first second; lntub = intubation; Trach = tracheotomy; ICD = intercurrent disease. Laryngoscope 11 O: January

3 Fig. 1. A. Bilateral vocal cord paralysis (patient 11, forced inspiratory volume during the first second (FIV- 1 ): 0.9 L). B. The right vocal cord is placed in paramedian position (first postoperative first month, FIV-1: 1.8 L), C. The vocal cords recovered (second postoperative month, FIV-1 : 2.3 L). The abduction of the rig ht vocal cord also improved despite the laterofixing suture. D. Stationary stroboscopic photography after removal of the laterofixing suture: the glottic closure and the voice completed (digitized video pictures). Spirometric Measurements and Follow-up Preoperativ and postoperative airway function tests and videolaryngoscopy were conducted on each of the patients. Measurem nts were made before the laterofixation procedttre (when poss ible) and on postoperative days 1 through 5. The follow-up exa minations were made from 2-week to 1-month intervals in the first year to det ct vocal cord recovery as soon as possible. Radiological examin ation of the aspiration was performed in 13 patients at the end of the first postoperative month. RESULTS After unilateral vocal cord laterofixation, each patient awak ned without difficulty and the two previous trach eotomies were closed immedi ately. Severe postoperative edema was found in only three cases, but they could be managed without reintubation or trach eotomy. The spirometry performed on postoperative days 1 to 5 revealed a m arked increase in forced inspiratory volume during the first second (Fig. 1 B). Patients 1 a nd 4 were found to have mild mediali zation in cord position during the first 3 months aft r surgery. Concurrently, these pa tients' spirometric values worsened somewhat. However, this change was not significant, the positions of the cords and the spirometric values stabilized, and no dyspnea was noted. Marked medialization presented only in patient 3, after a kidney transpla n tation that was performed 2 weeks after the laterofixation procedure. After a repeated laterali zation procedure on the same side, the patient's breathing improved, but she di cl 3 months later from complication s of the transplantation. An elderly patient di ed in the 14th postoperative month from a n intercurrent disease. One patient was lost to follow-up, but sh e has been symptom free so far according to information gained from her general practitioner. 142 For the remainder of our patients, their a irways have been stable during the follow-up (Fig. 2). However, the patients' dysphonia grew significantly worse after surgery, and their voices became hoarse and weak. The contralateral vocal cord started to move 1 to 5 months after the laterofixation in seven patients and complete recovery followed in five of these patients within a further 2 to 7 weeks. After careful evaluation of breathing function, larynx size, and general condition, we decided to release the fixed cord in four patients. One other suture was removed later from one elderly patient in the 89th week because inflammation presented around the sutu're. Her breathing remained stable, because of the subsequent Fig. 2. The larynx of a 70-year-old woman (patient 5) in the 24th postoperative month. The left vocal cord is placed in full abduction (FIV-1 : 1.4 L). The epithelized latera lizing suture can be seen.

4 further improvement of the contralateral vocal cord movement. Significant vocal cord medialization was observed up to 2 weeks after these procedures. Movement was also re-established in one of these previously laterofixed cords (Fig. 1). The recovery of one laterofixed vocal cord was detected in the 8th postoperative month (the contralateral side remained paralyzed). The vocal cord adduction movement improved after the removal of the fixing suture. The voice quality of these patients significantly increased proportionally by the medi ali zation or recovery of the vocal cords. Swallowing on the side of the laterofixation was painful for all patients and mild aspiration was observed in some cases in the first postoperative days. No patient showed aspiration later either clinically or radiologically during follow-up and no further complications occurred. The thread cut into the substance of the vocal cord and the mucosa above it epithelialized approximately 10 days from the surgery. Granulation did not occur in the larynxes. DISCUSSION The advantage of the endo-extralaryngeal suture technique compared with the exo-endolaryngeal techniques is clear: the fixing thread can be inserted more easily and precisely with Lichtenberger's needle canier, which was constructed especially for endo-extralaryngeal sutures. But the use of this instrument in itself did not provide the improved results hypothesized in our series. In three of our first four patients, in whom the combination of Kleinsasser laryngoscope and intubation was used for the surgery, 10 more or less severe spontaneous medialization was observed in the first postoperative months. For this reason we revised our endoscopic surgery technique in some respects. In our series the combination of the supraglottic JET ventilation and the Weerda laryngoscope provided the best way to maneuver with the needle carrier instrument in the larynx when the patient had not been previously tracheostomized. So proper thread insertion becomes possible just around the vocal process; in our experience, this is possibly the key factor of these simple lateralization procedures. The vocal process provides a more stable surface for the thread than the membranous part of the vocal cord, so postoperative medialization can be reduced. A further advantage of the correct suture insertion is that the anatomical structure of the vocal fold remains intact, which is important as concerns later voice function. 6 In terms of long-term effectiveness, whether the fixing thread cuts into the vocal cord substance or the prelaryngeal muscles is significant. The use of a wider thread (Prolene 0 instead of the Prolene 2-0 originally suggested 10 ) might also play a role in the fact that medialization decreased to less than 0.5 to 1 mm in the last 11 patients, as evidenced by the stable inspira tory values for these patients (Table I). In our series the muscles provide an appropriate "fl exible" base for the fixing thread. Atrophy of the cartilage is thus avoided and the use of an external silicone platelet is not n ecessary.13 Because access to the thyroid ala is not necessary, in our experience the whole operation takes approximately 10 to 15 minutes. At the beginning of this study the selection of the side to be operated appeared to be a cardinal question. In another group of patients who suffered from posterior glottic stenosis and who were operated on by a similar lateralization technique, we found that laterofixed cord movement can be detected by careful observation. 14 Improvement of vocal cord abduction movements was detected in patients 10 and 11 (Fig. 1B and C) despite the laterofixation sutures. Laryngeal electromyography 1 5 might also be a useful tool for detecting this recovery in questionable cases. Obviously, laterofixation should be performed on the side where paralysis is irreversible or where the nerve injury is presumably more severe (d ue to n erve infiltration by tumor, resection, and so forth). A previous nerve injury in their history clearly indicated the side of the laterofixation in three patients. This method is minimally invasive and the generally moderate postoperative edema can be controlled effectively by a combination of intravenous and inhaled steroids, so an appropriate airway can be achieved even in the first postoperative days. The endolaryngeal overepithelization of the thread takes approximately 10 days, so the use of a wide-spectrum antibiotic is suggested to prevent the spread of bacterial infection from the larynx into the deeper layers of the neck. Airway resistance decreases more than Jin arly by enlargement of the diameter in cases of upper respiratory tract stenosis. Other determining factors, such as the narrowing effect of the inspiration on the paralyzed glottis (Bernoulli's effect) and the turbulence, also decrease concurrently with the deceleration of the flow.16 Therefore, the relatively smaller enlargement of the glottis leads to a significant decrease in laryngeal resistance. Supraglottic JET ventila tion provides a n excellent evaluation of the glottic diameter, thus it becomes possible during surgery to determine individual glottis width (depending on the patient's larynx size, cardiorespiratory state, profession, and so forth). Thus the postoperative voices of our patients became weaker-in inverse proportion to the adequacy of the airway achieved-but socially.acceptable in most cases. Ejnell at al. 9 reported si milar findings. Clinical observation demonstrates that temporary laterofixation of the vocal cord can be done without causing any lasting damage ifthe thread is removed within 10 weeks. 5 In our series the patients' voices improved due to more or less overcompensation at phonation after the recovery ofcontralateral cord mobility. In cases in which the fixing thread was removed, the vocal cord position became more medi al. This might happen as much as 2 years after surgery, resulting in further voice improvement, as evidenced by patient 7. The small phonation gap, which remained at the site of the suture in th e posterior glottic chink, had no significant influence on voice quality. According to the patient, complete restoration of the preoperative voice was achieved when recovery was bilateral (Fig. ld). In the case of a late (more than 6-8 mo) removal of the fixing suture, the immediate results might not be as impressive, as in the case of patient 13. Muscle fibrosis,4 development of pathological voice production (false vocal cord phonation, and so forth), and only partial reinnervation may have played a role in this case. Speech therapy 143

5 was effective, but tills fact su ggests the need for the r e mova l of the fixing suture as soon as possible. In case of a pa tient with small larynx and with poor cardiorespiratory status or only partial vocal cord recovery, fixed cord mobilization must be evaluat d individually. Jn contrast to early laterofixation, the similar simple laterofixation in patients several months after the onset of paralysis has not always been satisfactory We assume that the continuous ten sion produced by a fixed arytenoid joint causes the fixing thread to cut through the vocal cord substance, resulting in medialization. In contrast, a mobile arytenoid cartilage can be easily rotated in the early period, which is an important fact in carrying out the vocal cord laterofixation procedure as soon as possible. Most of our patients were able to retw'n to their previous lifestyles without difficulty after a short period of time. There were no significant complaints as concerns swallowing. The absence of aspiration probably can be explained by th intact sen sorial innervation of the lru ynx. A similar exp erience was reported by Geterud et aj.1 7 CONCLUSION Our experience suggests that early ndo-extralaryngeal vocal cord laterofixation provides a reliable alternative for treating patients with bilateral vocal cord paralysis. This procedure is reversible to a large extent, so the vocal cord function is not sacrificed entirely. The most significant featur, how ver, is that recovery of cord mobility can be exp cted without the n eed for tracheostomy, and it might provide a one-stag solution to the problem of suffocation when the bilate_ral recurr nt nerve injury h as proved to be p rma nent. BIBLIOGRAPHY 1. Echeverry A, Flexon PB. Electrophysiologic n rve stimulation for identifying the recurrent laryngeal nel've in thyroid surgery: revue of 70 consecutive thyroid surgeries. Am Surg 1998;64(4): Friedrich T, Steinert M, Keitel R, Sattler B, Schonfelder M. Incid nee of damage to the recurrent laryngeal nerve in surgical therapy of variou s thyroid gland diseases - a retrospective study. Zentralbl Chir 1998;123(1): Kull C, Breu M, Hoffmann M, Rittmann WW. Paralysis of the recurrent laryngeal ne!'ve following strumectomy in late follow-up. Helu Chir Acta 1989;55: Zealear DL, Hamdan AL, Rainey CL. Effects of denervation on posterior cricoarytenoid muscle physiology and histochemistry. Ann Otol Rhinol Laryngol 1994;103: Ejnell H, Tisell LE. Acute temporary laterofi.xation for treatment of bilateral vocal cord paralyses after surgery for advanced thyroid carcinoma. World J Surg 1993; 17: Gould JW, SataloffRT, Spiegel JR. Voice Surgery. St. Louis; Mosby-Year Book, 1993: Tucker HM. The larynx. New York: Thi eme Medical Publisher; 1987: Hawthorne MR, Nunez DA. Bilateral vocal cord palsy: the alternative to tracheotomy. J Otolary ngol 1992;2 1: Ejnell H, Mansson I, Ha llen 0, Bake B, Stenborg R, Lindstrom J. A simple operation for bilateral vocal cord paralysis. Laryngoscope 1984;94: J6ri J, Rov6 L, Czigner J. Vocal cord lalerofixation as early treatment for acute bilateral abductor paralysis after thyroid surgery. Eur Arch Otorhinolary ngol 1998;255: Lichtenberger G. Endo-extralaryngeal needle carrier instrument. Laryngoscope 1983;93: Lichtenberger G, Toohi ll RJ. Endo-extralaryngeal suture technique for endoscopic lateralization of paralyzed vocal cords. Oper Techn Otolaryngol Head Neck Surg 1998;9: Moustafa H, Guindy A, Sherief S, Targam A. The role of endoscopic laterofixation of vocal cord in the treatment of bilateral abductor paralysis. J Laryngol Otol 1992;106: Rov6 L, J6ri J, Brz6zka M, Czigner J. Minimally invasive surgery for posterior glottic stenosis. Arch Otolaryngol Head Neck Surg 1999;121: Woo P. Laryngeal electromyography is a cost effective clinically useful tool in the evaluation of vocal fold fw1ction. Arch Otola1yngol Head Neck Surg 1998;124(4): Fung FC. Biodynamics. New York: Springer-Verlag, 1984;3: Geterud A, Ejnell H, Stenborg R, Bake B. Long-term. results wi th a simpl e surgical treatment of bilateral vocal cord paralysis. Laryngoscope 1990;100: