- Email: [email protected]
Novel Technique of Silastic Implant Carving for Thyroplasty Type I Surgery
Otolaryngology–Head and Neck Surgery (2005) 133, 629-630
CLINICAL TECHNIQUES AND TECHNOLOGY
Novel Technique of Silastic Implant Carving for Thyroplasty Type I Surgery Steven J. Charous, MD, Chicago, Illinois
U
ndoubtedly, there are many techniques available whose goal is to obtain normalization of voice by medializing a paralyzed or bowed vocal fold.1,2,3,4,5 Also without doubt, each of these techniques, performed by the right hands and in the right patient, will produce excellent results. Cited difficulties with carved implants are that the silicone is difficult to carve and the hand-carved silicone implant greatly increases the length of surgery.4 Window placement is also a problem with many techniques because, as Maragos states, “the correct placement of the vocal fold line is the ultimate key to success of any thyroplasty operation. A misplaced line will cause total failure.”5 The technique presented may help solve some block carving issues as well as allow some variability in window placement. The technique is based on the Netterville et al1 technique, in which a silastic block is inserted into a window created in the thyroid cartilage while the patient is sedated. A window 5 mm x 10-13 mm, leaving a 3-mm cartilage strut paralleling the lower border of the thyroid cartilage, is created. The distance of the window from the midline varies depending on the sex of the patient and the acuteness of the thyroid cartilage’s angle. (One can also use Isshiki’s3 method of determining location of the window placement.) The cartilage is excised from the window no matter which method is chosen. A flexible laryngoscope is inserted through the patient’s nose and suspended. Although the procedure could be performed using vocal quality alone to determine correct placement of the implant, visualization creates confidence in implant positioning. The depth and location of the optimal medialization point are determined by pressing in the thyroid window using a depth gauge. Then, the implant is fashioned from a silicone block (Medtronic Xomed, JackFrom the Department of Otolaryngology, Rush University Medical Center, Chicago, IL Reprint requests: Steven J. Charous, MD, 3633 West Lake Avenue, Glenview, IL 60025.
sonville, Fla). Three-millimeter struts of the Silastic block are cut on a separate sterile table (see Fig 1). The strut is fashioned into a triangular form such that its maximal height matches the depth previously determined in the larynx and the point of maximal height lies at the correct inferiorsuperior position in relation to the window (see Fig 2). (This is easier done than said.) For example, if the ideal depth is 5 mm and the ideal location is in the center of the window, then a triangular implant is created with a 5-mm peak in the middle of an isosceles triangle. If, however, the location of ideal medialization lies inferior or superior to the middle aspect of the window, the peak height of the implant will be made the same distance from the center of the implant as the medialization point is to the center of the window. By means of forceps, the implant is easily placed in the
Figure 1 Slicing 3-mm struts from Silastic block before determining maximal point of medialization.
E-mail: [email protected].
0194-5998/$30.00 © 2005 American Academy of Otolaryngology–Head and Neck Surgery Foundation, Inc. All rights reserved. doi:10.1016/j.otohns.2005.04.030
630
Otolaryngology–Head and Neck Surgery, Vol 133, No 4, October 2005
Figure 2 (a) Possible carved implants with location of implant’s peak height depending on superior-inferior point of ideal medialization. (b) Three struts in place, with Prolene suture for stabilization.
previously designated spot. Once the first implant has been placed successfully, the depth gauge is again used to determine the amount of medialization required anteriorly or posteriorly to the placed implant. With the first implant in place, 1 or 2 more implant struts are added anteriorly, posteriorly, or both. This is something of a “fine-tuning” aspect of the procedure. Typically 3 struts are placed in total so that the struts are immobile. Small larynges may require only 2 struts if the window is created smaller. The struts are secured in place, with 3-0 Prolene gently suturing the implants together and to either strap muscle or perichondrium. This procedure uses the basic materials and philosophy previously described by Netterville et al.1 The difference is creating a 3-dimensional implant in “2-dimensional pieces,” one at a time. (Although the struts are truly 3 dimensional, by standardizing the thickness, one is designing only 2 dimensions of each strut at a time.) The slim struts have several advantages over the larger block: (1) Efficiency. Each strut takes less than 1 minute to carve and thus minimizes the duration of the procedure and the vocal-fold edema that occurs with increased manipulation and time. (2) Technical ability required. It is technically simple to create a strut because each strut is 2-dimensionally designed, although the end result is 3 dimensional. In contrast, in the block technique, significant finesse is required to carve a 3-dimensional implant. (3) Placement. An unsuccessful strut is easily removed, reshaped, or replaced. A Silastic block, however, is more difficult to place and remove because of its size, and it is even more difficult to determine how to reshape or improve on its 3-dimensional shape. (4) Fine-tuning. Placing one strut at a time allows for “finetuning” and adjustments to be made in the second and third struts. This is not possible when placing 1 large block in at once. (5) Flexibility. The ability to place the maximal height exactly where necessary and nowhere else allows for the variability that can occur in window placement or in the size
and location of the vocal folds. This flexibility is not available in other systems where window location is critical. This method’s flexibility is especially useful in revising unsatisfactory medialization attempts that used other methods. Despite improper window placement or inaccurately sized or placed implants, newly fashioned 3-mm strut implants can be created easily to compensate for the prior inadequacies. Thus far, no extrusions, airway obstructions, or other complications have occurred in the approximately 30 procedures (with an average follow-up of approximately 18 months) done over the past 3 years. A formal study comparing methodologies is not being undertaken, nor has this technique been formally evaluated yet. Patients have been satisfied with their postoperative voices, and to date none have required or requested revision surgery. Postoperative videostroboscopies have demonstrated excellent vocal-fold closure. In cases of large posterior gaps, arytenoid adduction is performed as it is with other thyroplasty type I techniques. In conclusion, the purpose of this paper is to introduce a modified surgical procedure that may be technically easier, and perhaps more reliable for the surgeon performing thyroplasty type I surgery.
REFERENCES 1. Netterville JL, Stone RE, Luken ES, Civantos FJ, Ossoff RH. Silastic medialization and arytenoid adduction: the Vanderbilt experience. Ann Otol Rhinol Laryngol 1993;102:413–24. 2. Isshiki N, Morita H, Okamura H, Hiramoto M. Thyroplasty as a new phonosurgical technique. Acta Otolaryngol 1974;78:451–3. 3. Isshiki N, Taira T, Kojima H, Shoji K. Recent modifications in thyroplasty type I. Ann Otol Rhinol Laryngol 1989;98:777–9. 4. Montgomery WW, Montgomery SK. Montgomery Thyroplasty implant system. Ann Otol Rhinol Laryngol 1997;106:1– 6. 5. Maragos NE. Type I thyroplasty: pitfalls of modifying the Isshiki approach: how I do it. J of Voice 1997;11(4):470 –3.
CLINICAL TECHNIQUES AND TECHNOLOGY
Novel Technique of Silastic Implant Carving for Thyroplasty Type I Surgery Steven J. Charous, MD, Chicago, Illinois
U
ndoubtedly, there are many techniques available whose goal is to obtain normalization of voice by medializing a paralyzed or bowed vocal fold.1,2,3,4,5 Also without doubt, each of these techniques, performed by the right hands and in the right patient, will produce excellent results. Cited difficulties with carved implants are that the silicone is difficult to carve and the hand-carved silicone implant greatly increases the length of surgery.4 Window placement is also a problem with many techniques because, as Maragos states, “the correct placement of the vocal fold line is the ultimate key to success of any thyroplasty operation. A misplaced line will cause total failure.”5 The technique presented may help solve some block carving issues as well as allow some variability in window placement. The technique is based on the Netterville et al1 technique, in which a silastic block is inserted into a window created in the thyroid cartilage while the patient is sedated. A window 5 mm x 10-13 mm, leaving a 3-mm cartilage strut paralleling the lower border of the thyroid cartilage, is created. The distance of the window from the midline varies depending on the sex of the patient and the acuteness of the thyroid cartilage’s angle. (One can also use Isshiki’s3 method of determining location of the window placement.) The cartilage is excised from the window no matter which method is chosen. A flexible laryngoscope is inserted through the patient’s nose and suspended. Although the procedure could be performed using vocal quality alone to determine correct placement of the implant, visualization creates confidence in implant positioning. The depth and location of the optimal medialization point are determined by pressing in the thyroid window using a depth gauge. Then, the implant is fashioned from a silicone block (Medtronic Xomed, JackFrom the Department of Otolaryngology, Rush University Medical Center, Chicago, IL Reprint requests: Steven J. Charous, MD, 3633 West Lake Avenue, Glenview, IL 60025.
sonville, Fla). Three-millimeter struts of the Silastic block are cut on a separate sterile table (see Fig 1). The strut is fashioned into a triangular form such that its maximal height matches the depth previously determined in the larynx and the point of maximal height lies at the correct inferiorsuperior position in relation to the window (see Fig 2). (This is easier done than said.) For example, if the ideal depth is 5 mm and the ideal location is in the center of the window, then a triangular implant is created with a 5-mm peak in the middle of an isosceles triangle. If, however, the location of ideal medialization lies inferior or superior to the middle aspect of the window, the peak height of the implant will be made the same distance from the center of the implant as the medialization point is to the center of the window. By means of forceps, the implant is easily placed in the
Figure 1 Slicing 3-mm struts from Silastic block before determining maximal point of medialization.
E-mail: [email protected].
0194-5998/$30.00 © 2005 American Academy of Otolaryngology–Head and Neck Surgery Foundation, Inc. All rights reserved. doi:10.1016/j.otohns.2005.04.030
630
Otolaryngology–Head and Neck Surgery, Vol 133, No 4, October 2005
Figure 2 (a) Possible carved implants with location of implant’s peak height depending on superior-inferior point of ideal medialization. (b) Three struts in place, with Prolene suture for stabilization.
previously designated spot. Once the first implant has been placed successfully, the depth gauge is again used to determine the amount of medialization required anteriorly or posteriorly to the placed implant. With the first implant in place, 1 or 2 more implant struts are added anteriorly, posteriorly, or both. This is something of a “fine-tuning” aspect of the procedure. Typically 3 struts are placed in total so that the struts are immobile. Small larynges may require only 2 struts if the window is created smaller. The struts are secured in place, with 3-0 Prolene gently suturing the implants together and to either strap muscle or perichondrium. This procedure uses the basic materials and philosophy previously described by Netterville et al.1 The difference is creating a 3-dimensional implant in “2-dimensional pieces,” one at a time. (Although the struts are truly 3 dimensional, by standardizing the thickness, one is designing only 2 dimensions of each strut at a time.) The slim struts have several advantages over the larger block: (1) Efficiency. Each strut takes less than 1 minute to carve and thus minimizes the duration of the procedure and the vocal-fold edema that occurs with increased manipulation and time. (2) Technical ability required. It is technically simple to create a strut because each strut is 2-dimensionally designed, although the end result is 3 dimensional. In contrast, in the block technique, significant finesse is required to carve a 3-dimensional implant. (3) Placement. An unsuccessful strut is easily removed, reshaped, or replaced. A Silastic block, however, is more difficult to place and remove because of its size, and it is even more difficult to determine how to reshape or improve on its 3-dimensional shape. (4) Fine-tuning. Placing one strut at a time allows for “finetuning” and adjustments to be made in the second and third struts. This is not possible when placing 1 large block in at once. (5) Flexibility. The ability to place the maximal height exactly where necessary and nowhere else allows for the variability that can occur in window placement or in the size
and location of the vocal folds. This flexibility is not available in other systems where window location is critical. This method’s flexibility is especially useful in revising unsatisfactory medialization attempts that used other methods. Despite improper window placement or inaccurately sized or placed implants, newly fashioned 3-mm strut implants can be created easily to compensate for the prior inadequacies. Thus far, no extrusions, airway obstructions, or other complications have occurred in the approximately 30 procedures (with an average follow-up of approximately 18 months) done over the past 3 years. A formal study comparing methodologies is not being undertaken, nor has this technique been formally evaluated yet. Patients have been satisfied with their postoperative voices, and to date none have required or requested revision surgery. Postoperative videostroboscopies have demonstrated excellent vocal-fold closure. In cases of large posterior gaps, arytenoid adduction is performed as it is with other thyroplasty type I techniques. In conclusion, the purpose of this paper is to introduce a modified surgical procedure that may be technically easier, and perhaps more reliable for the surgeon performing thyroplasty type I surgery.
REFERENCES 1. Netterville JL, Stone RE, Luken ES, Civantos FJ, Ossoff RH. Silastic medialization and arytenoid adduction: the Vanderbilt experience. Ann Otol Rhinol Laryngol 1993;102:413–24. 2. Isshiki N, Morita H, Okamura H, Hiramoto M. Thyroplasty as a new phonosurgical technique. Acta Otolaryngol 1974;78:451–3. 3. Isshiki N, Taira T, Kojima H, Shoji K. Recent modifications in thyroplasty type I. Ann Otol Rhinol Laryngol 1989;98:777–9. 4. Montgomery WW, Montgomery SK. Montgomery Thyroplasty implant system. Ann Otol Rhinol Laryngol 1997;106:1– 6. 5. Maragos NE. Type I thyroplasty: pitfalls of modifying the Isshiki approach: how I do it. J of Voice 1997;11(4):470 –3.