Introduction

Transoral laser microsurgery (TLM) is a worldwide, time-honored technique for early laryngeal carcinoma treatment, in the past 35 years, it has been developed and refined. Based on the excellent results for early larynx cancer, it is also being used for cancer treatment of the whole superior aerodigestive tract¹.

In the early 70’s, laser microsurgery was first used by Strong and Jako in the United States²; however, several reports from European countries described technical improvements and resection classification types³ and began to publish the first series of patients treated with laser microsurgery⁴. In America, it was not until 2000 when interesting reports were published from different authors in the United States⁵-⁸. In this context, the expansion of TLM took longer to influence Latin America⁹ where very scant information can be found about its progress and applicability in the region. In 2004, we published in the Mexican medical literature the technique and principles of transoral laser surgery based on the teachings of Dr. Wolfgang Steiner at Georg-August-University in Goettingen, Germany¹⁰.

In the present manuscript, we describe the experience in early glottic carcinoma laser microsurgery treatment at a Tertiary Care Hospital in Mexico City.

Materials and methods

Data analysis

Results

Forty patients were included in the analysis: 4 pTis (10%), 19 pT1a (47%), 8 pT1b (20%), and 9 pT2 (23%). There were 36 male and 4 female patients, the mean patient’s age was 67 years (range 39-82). Mean patient follow-up time was 7.4 years (range 3-12.9 years). The average post-operative hospital stay was 2.75 days (0-15 days). Only 1 patient (2.5%) presented bleeding as a post-operative major complication, in his 2^nd post-operative day, that required urgent revision surgery with prophylactic tracheotomy and had the longest hospital stay (15 days) (Table 1).

Recurrence occurred in 4 patients (10%), one of them did not receive additional treatment because it had no implication in his quality of life, he died of non-related cancer cause. Another patient had revision TLM with adequate local control; however, he developed a second primary in the lung during his 5^th year of laryngeal carcinoma follow-up for which he received chemotherapy, he is alive without disease. The third patient had a local recurrence at his 5^th follow-up year, he received radiotherapy and is alive without disease. Finally, the fourth patient with recurrence was treated with total laryngectomy and chemoradiotherapy; unfortunately, he died with locoregional disease.

Twenty-nine patients (72.5%) are alive without disease, nine patients (22.5%) died disease-free of non-cancer-related causes, 1 patient (2.5%) died with disease of non-cancer-related cause, and another one (2.5%) died of the disease (Fig. 1).

Figure 1 Survival status. AWOD: alive without disease; DWOD: dead without disease; DWDCR: dead with disease cancer-related cause; DWDCNR: dead with disease cancer not related cause. 

In our cohort, the Kaplan–Meier results at 3 and 5-year estimates were as follows: overall survival (OAS) was 92.5% and 87%, respectively; laser only local control (LLC) was 94.9 and 91.6%, respectively; and DSS and ULC rate were 97.5% for both time periods (Figs. 2-5). We found a 97.5% (39/40) OP rate.

Figure 2 Kaplan–Maier overall survival curve. 

Figure 3 Disease specific survival Kaplan–Meier curve. 

Figure 4 Laser only local control Kaplan–Meier curve. 

Figure 5 Ultimate local control Kaplan–Meier curve. 

Discussion

Medical technologic advances take some time to be established as “standard” therapeutic modalities. They must prove their efficacy at the site of conception to convince colleagues of its applications. Sometimes the technique also defies the so-called “unbreakable” principles of medicine and skepticism keeps it on the shelf for more time than expected, as in oncological endoscopic laser microsurgery. This type of surgery requires Hi-Tec equipment and costs may also seem a limitation to the low-income countries. All the latter have delayed laser microsurgery as being considered a reasonable treatment option for laryngeal carcinoma in Mexico.

Our institution is a public, general, and teaching hospital in Mexico City which offers laser microsurgery as a standard modality for laryngeal carcinoma treatment. Through all these years, we have learned that to perform successfully this procedure, training, equipment, technique, and close patient follow-up are very important and need to be taken seriously by surgeons who are willing to perform this technique.

The special parameters of laser beam manipulation (continuous wave, pulsed, super pulsed/continuous, single pulse, and repeated pulse) will interact differently with tissue to acquire the desired results. One principle of laser microsurgery is the ability to recognize tumor limits and invasion according to the degree of carbonization during laser cutting¹, so excessive carbonization is not desired using high laser output.

Since laser microsurgery conception, surgeons have made efforts to implement classifications to compare results of laryngeal laser resections³-⁵,¹³-¹⁵, as with its external approach counterpart. However, we found them difficult to apply to our patients, as laser microsurgery is a self-tailored technique, in which there are as many variations as patients treated. We followed the principles of resection described by Steiner and Ambrosch¹.

Even though bleeding is the most common complication reported by other authors¹⁶, it has a very low presentation rate. In the present study, 1 patient (2.5%) presented this complication on the 2^nd post-operative day, Ellies and Steiner¹⁷ report a 1.4% and Vilaseca-González¹⁸ a 2.9% bleeding rate for glottic resections; they consider that the extension of resection and the surgeon experience are important factors leading to this complication¹⁶,¹⁸. Our patient was one of our first transoral laser surgery cases, we performed a revision surgery for hemostatic control and a temporary prophylactic tracheotomy. We consider that our learning curve and better instrumentation (hemostatic laryngeal surgery alligator forceps) helped to prevent further bleeding events in our patients and we would not consider making prophylactic tracheotomy now in the same clinical situation.

In our study, the 5-year overall survival rate was 87%, which is similar to that reported by Pradhan¹⁹ (84.1%) and Huang²⁰ (89.4%). The 5-year DSS rate in our series was 97.5%, similar to reports from other authors such as Eckel²¹ and Moreau¹³ (97%).

OP rate has been reported by Eckel²¹, Ledda²², Schrijvers²³, Grant²⁴, Ambrosh²⁵, and Ellies and Steiner¹⁷ from 89% to 100%, whereas we achieved an OP rate of 97.5%.

The 5-year laser alone local control of our cohort was 91.6% while it has been reported in 93% in different series¹⁴,²⁰,²¹, our 5-year ULC was 97.5%, where as we found a 98.7%14,20,21,25,26 reported in the literature. Fortunately, we gladly found that our results are similar as other experienced authors have reported²⁴,²⁷,²⁸ (Table 2).

It is important to mention that multiple efforts have been made to compare oncologic and functional results between endoscopic laser microsurgery and radiotherapy, but this has been difficult because randomized controlled multicenter studies are not yet available²⁹. Taken these in mind, the oncologic results for TLM tend to be better than with radiotherapy (RT) at 5-year estimates³⁰,³¹; TLM versus RT: LC 85% versus 82%, OAS 84% versus 75%, DSS 94% versus 87%, and OP 89% versus 79%. Regarding open partial laryngectomy (OPL), this technique has higher morbidity and longer recovery time than TLM. However, as it is a more “radical” procedure, the oncologic results have been reported better than it is endoscopic counterpart³⁰; OPL versus TLM: LC 96% versus 85% and OS 89% versus 84%.

Conclusion

Endoscopic laser microsurgery for the treatment of early glottic carcinoma has proved adequate oncological results since its conception and has gathered more than 35 years of experience around the world. Fortunately, we were also able to reproduce the technique and results reported by diverse authors in Europe and in the United States of America following the step-by-step principles described and developed by Dr. Wolfgang Steiner. It is important to say that proper training with adequate surgical equipment and instrumentation is mandatory to achieve this goal.

Due to our results, we consider that laser microsurgery could be performed in other institutions in our country.