The use of TiNi-based endografts in larynx cancer patients
Purpose: Laryngeal cancer constitutes 26-30% of all head and neck malignant tumors. It is remarkably common in men and it is primarily distributed between ages 40 and 70 years old, but the frequency rate is the highest between ages 50 and 60. Well-known etiologic factors of laryngeal cancer include smoking, alcohol, human papilloma virus and radiation. It has been reported that the occurrence rate is up to 20 times higher in smokers compared to non-smokers, but the exact pathogenesis of the disease is still unknown.
Despite an increasing role of non-adjuvant radiotherapy and/or chemotherapy in treatment of larynx cancer, the surgical technique is still a basic one both in combined treatment of patients with locally advanced stages of primary larynx cancer and in the cases when recurrence is treated after radiotherapy or chemoradiotherapy. Leading position in the combined treatment of locally advanced carcinoma of the larynx belongs to surgical treatment. Published reports of salvage treatment for larynx reconstruction after partial laryngectomy are available, some of them using structures of the larynx itself, but few aimed on a search of new materials and techniques for sparing laryngeal surgery.
Possibility to perform a sparing surgery depends on several factors, including, the possibility of adequate laryngeal replacement after an extensive resection. Meanwhile, surgery improvement goes along with differentiated choice of an adequate degree of surgical intervention. However, the functional results of such surgeries do not always satisfy both patients and professionals, if we consider that large fragments of the organ have to be resected in locally advanced larynx cancers.
The larynx reconstruction is a complex goal, it can be explained by several factors. First of all, this is topographic and anatomical feature of the larynx since it is located next to the digestive tract. Fixation and immobilization of the larynx is hard to perform as it is a mobile organ when swallowing, speaking etc. Secondly, there are no commercially produced endografts for wide clinical practice. Thirdly, there are high demands regarding the material selection for the replacement. This study aimed to present the new technique of sparing surgery in patients with laryngeal cancer.
Methods: Totally 120 patients with laryngeal cancer were observed with stage grouping T2-3N0-1M0 (Т1N0M0 – 14, Т2N0M0 – 40, T3N0M0 – 58, T2N1M0 – 8). Most of them (118, 98.3%) were males where patients’ age ranged from 32 to 70 years (Tab. 1). The maximum number of patients (78%) was in 40–60 years group. Not all of those in the laryngeal cancer group were newly diagnosed and they received previous treatment. Informed consent was obtained from each patient. The subsites of laryngeal cancer were the glottis in 17 cases, the supraglottic-glottis in 45 cases and the transglottic in 58 cases.
The intervention depended on the location and extent of the tumor process. Standard volume of resection, extended resection, combined resection, subtotal resection were basic types of surgery. Most of laryngeal resections were front-lateral (117, 98%) and there were only three (2%) subtotal ones. Surgeries on the primary focus were combined with cervical lymph node dissection in eight patients (6.6%). The essence of the resection is to remove larynx structures which are affected by neoplastic process as a single unit including mucosa, submucosa layer, muscles, thyroid cartilage with the inner perichondrium into the volume of cut out tissue.
Both the creation of laryngeal frame using the endograft made of superelastic TiNi-based alloy mesh and the providing of the inner lining of the recovered larynx is the basis of sparing technique regarding the larynx prosthetics.
Producing of original design endograft made of superelastic TiNi-based alloy mesh was performed individually for each patient using the data acquired by helical CT of the larynx, laryngoscopy and volume of upcoming surgery. The endograft is a framework made of two twisted superelastic TiNi-based wires (TN-10 brand alloy) having 0.4 mm dia provided by Kang&Park Medical Co. (S. Korea). It is further covered with superelastic TiNi-based alloy mesh. The mesh is constructed of knitted filaments made of the same TN-10 brand alloy wire, which stress-strain behavior is identical to human body tissues. This mesh is thin, flexible and laminate designed for the repair of hernias, ruptured tendons, and other fascial deficiencies. This material, when used in vivo, has been reported to be non-reactive and to retain its properties indefinitely in wide clinical use. The mesh 0.1-0.15 mm thick is knitted by a process which interlinks each fiber junction and provides for superelasticity in any direction. Such design enables the mesh to be cut off into any desired shape or size without unraveling. The fiber junctions are not subject to the same work fatigue showing by more rigid polypropylene or metal-based meshes. This any-directional superelastic property allows the mesh to be easily adapted to various stresses appeared in the human body. The mesh mentioned has been also commercially produced by Kang&Park Medical Co. (S. Korea).
This endograft design shows the superelastic behavior (at the time of physiological movements of the larynx during swallowing, breath and speech) recovering the shape of frame. The endograft described is radio-opacifying, unlike other endografts e.g. polymer-based endografts. This property makes it possible to control the position over time.
We used local muscle tissues (platysma) or muscle-flap prefabrication technique (flap of the rectus abdominis) for formation of the inner lining. 15 patients with laryngeal cancer (stage Т2-3N0M0) have been treated by using the technique.
All patients underwent different types of sparing surgeries (front-lateral laryngectomy – 3 cases, frontal laryngectomy – 6 cases, subtotal laryngectomy – 6 cases) with simultaneous replacement with the endograft described. These surgeries were performed in 5 patients (Т2N0M0 - 2 and Т3N0M0 - 3 cases) in terms of combined treatment (with preoperative radiotherapy dose 40 Gy). 10 patients (rT2N0M0 – 3 and rT3N0M0 - 7 cases) had recurrent laryngeal cancer after radical radiotherapy. In 9 cases we used the platysma flap and in 6 cases we did muscle-flap prefabrication technique (flap of the rectus abdominis) with inclusion of the endograft for formation of the inner lining of the larynx wall. Muscle-flap prefabrication technique consists of an implantation of pre-created superelastic TiNi mesh into the rectus abdominis muscle. When the time of prefabrication (about 3–4 weeks) was over we performed reconstructive surgery using this prepared muscle flap with inclusion of the endograft. Such autograft was included in the blood flow by means of microvascular anastomosis applied between the recipient and donor vessels (as a rule - superior thyroid artery and vein).
Results: Analyzing sparing operations using endografts described we achieved the following functional results. Voice function was completely saved in 112 (93.3%) cases and partially in 8 ones (6.7%). Respiratory function was fully restored in 106 (88.3%) patients, in 14 cases (11.7%) the cannula was not taken out from patients due to scar changes. The protective function of the larynx was saved in 116 (96.6%) patients. There was a temporary partial impairment of larynx protective function in four patients (3.4%).
Monitoring of the reconstructed larynx was traditionally based on laryngeal endoscopy, spiral CT study and scintigraphy. Laryngoscopy in 14 days after the operation showed the endograft coated with fibrin plaque with isolated islets of pink granulation tissue "approaching" from the periphery. Almost the entire surface of the endograft was coated with an even layer of tender granulation tissue in 30 days after the surgery. Mucous membrane on endograft edges is bright pink and shiny without signs of inflammation. In 3 months after the surgery - glottic chink lumen was not deformed, it was free, and endograft surface was covered with a tender pale pink mucous membrane. Entire endograft was coated with thin even layer. Morphological study of mucosa fragments taken from the surface of endografts in 12 months after surgery revealed the following: layered non-squamous flat epithelium with proper stratification; poorly expressed hyperplasia of basal cells. Such condition of epithelium proves complete reparative regeneration of mucosa without any signs of pathology. Impairment of epithelial differentiation was not detected in any site of mucosa studied.
Analysis of complications allowed to define that aftereffects as local inflammatory reactions nearby prosthetics region (perichondritis of larynx cartilages, mucosal edema of the larynx) were observed in 16 cases (13.3%) in postoperative period. These complications required additional medical treatment (antibiotics, photoradiotherapy, etc.). In particular, laryngectomy was performed in one case due to intractable laryngeal chondroperichondritis, severe pain and persistent impairment of swallowing function. In our study, laryngectomy was performed in 14 cases (11.7%) due to the continued growth of tumor during the first year after surgery according to the technique offered. Three (2.5%) patients died because of cancer progression. The 5-year and overall recurrence-free survival rates of all 120 patients were 83% and 76%, respectively.
Evaluation of results when we used sparing surgery applying modified approaches and endografts has shown that there was an exact match of endograft topology and larynx defects appeared. Helical computed tomography of the larynx has proven the correct state of the endograft and no migration in all the cases.
Conclusion: The developed sparing surgical treatment using TiNi-based endografts has shown the efficiency of laryngeal reconstruction in adverse conditions (trophic-inflammatory changes of the larynx after radiotherapy). Given the nature of techniques and postoperative course, we have formulated our indications for each method of reconstruction.
Using the flap of the platysma is more preferable in small reconstructions (after anterolateral laryngectomy). This method has the advantage of simplicity and one-stage reconstruction. Prefabrication method allows to get a prototype of the layerwise wall of the laryngeal cavity having the mucosal lining and vascular continuity. This method is preferable in reconstructing the large defect (subtotal laryngectomy) in patients with severe post-radiation changes in the larynx and the neck, as well as in case of postpone reconstruction.
The offered method of sparing treatment was finally turned out to be economically justified regarding treatment cost minimization. The results of functional rehabilitation of patients after surgical treatment using TiNi-based endografts permit to show preference for such surgery despite the fact that cannula was not taken out from a certain number of patients and there was a continued growth of tumor and recurrence. Compliance with the paradigm of malignant tumor metastasis and ablastics enables to hope that the number of complications will be reduced. Endografts made of TiNi-based mesh can adequately restore the frame function of the larynx, without postoperative aggravation. Both the local and displaced (prefabrication technique) tissues can be used in reconstruction of the inner lining of the larynx. Careful selection of patients, indications and replacement technique is necessary for such sparing surgery to be performed.
Cite this article as: Denis K, Marat M, Timofey C, Ji-Hoon K, Georgiy C, Valentina H, Victor G. The use of TiNi-based endografts in larynx cancer patients. Int J Cancer Ther Oncol 2015; 3(4):3404.
[This abstract was presented at the BIT’s 8th Annual World Cancer Congress, which was held from May 15-17, 2015 in Beijing, China.]
This work is licensed under a Creative Commons Attribution 3.0 License.
International Journal of Cancer Therapy and Oncology (ISSN 2330-4049)
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