Frans Hilgers

Medical and research background and activities

KNAW record

University of Amsterdam "Oncology related communication disorders"

This program, which since 2003 is embedded in the program
Speech Communication and Phonetic Sciences (Prof. Louis Pols ), aims at increasing our understanding of the pathophysiology of oncology related voice and speech disorders, potentially leading to improved rehabilitation and/or intervention strategies. Modern advances in the treatment of head and neck cancer have resulted in improved control rates, although often at the expense of impairment of functions of mouth, throat, and/or voice box. One of these advances is the application of special combined chemotherapy and radiotherapy protocols, which has also resulted in a higher likelihood of preservation of the treated organ. Unfortunately, preservation of an organ does not necessarily mean that its function remains unaffected. Loss of function is even more self-evident in case of surgical procedures, where all or part of an organ has to be removed for cure. Total laryngectomy (complete removal of the voice box) is the most obvious example of an operation, that has significant functional side effects, and, besides other consequences, leads to changes in voice and speech.
Presently the program focuses on the perceptual and acoustic determinants of speech intelligibility in laryngectomized individuals, who use a special implanted prosthesis for voice rehabilitation. Other oncology related voice and speech disorders as a result of head and neck treatment also are considered suitable for future projects within this program, which is carried out in close collaboration with the Netherlands Cancer Institute.
Institute of Phonetic Sciences

Intelligibility of tracheoesophageal speech

Total laryngectomy leads to a complete separation of the pharynx (throat) and trachea (wind pipe). This means that the normal way of voicing, using pulmonary air to evoke vibrations of the laryngeal mucosa is no longer possible. The implantation of a so-called voice prosthesis, which re-establishes the connection between the trachea and the pharynx, allows using pulmonary air to evoke vibrations, but now in the pharyngeal mucosa, allowing the patient to speak. The anatomical and functional characteristics of the new sound source that determine the quality of the voice have been studied extensively in recent years. The results of these studies are condensed in the thesis of C.J. van As, PhD (see also the recent literature list below). In the subsequent project we want to focus on the perceptual and acoustic determinants of speech intelligibility in laryngectomized individuals. This project is funded by the Breuning-ten Cate Foundation and is carried out in collaboration with Prof. Dr. Ir.Louis Pols (ACLC) and Dr. Corina van As and Dr. Maya van Rossum (Netherlands Cancer Institute). AIO is Petra Jongmans , MA. Duration 2003-2007.

Institute of Phonetic Sciences of the University of Amsterdam at Herengracht 338 for almost 40 years until August 2006 (now at Spuistraat 210).

Other ongoing projects

1. Pulmonary patho-physiology after total laryngectomy and the influence of Heat and Moisture Exchangers
Total laryngectomy not only affects communication, but inevitably also leads to pulmonary problems. Breathing is possible only through a permanent stoma at the base of the neck, which precludes the normal air-conditioning in the nose. Restoration of lost nose functions (partly) can be achieved by the peristomal application of so-called Heat and Moisture Exchangers (HMEs). The beneficial influence of these devices on pulmonary problems in laryngectomized individuals is established in several clinical trials, we carried out in the past. Interestingly, in all these studies significant correlations between pulmonary improvement and improvement in perceived voice quality were found. However, the underlying physiology of HMEs is not yet well understood, and the goal of this project is to improve our understanding in this respect. This might lead to technical improvements and efficiency of the present generation HMEs, not only resulting in a further increase in pulmonary health, but also in better voice quality and thus better quality of life of laryngectomized individuals. This project is funded by the Michiel Keijzer Foundation, which is related to the Netherlands Society of Laryngectomees (NSvG). This project is carried out in close collaboration with Dr. Annemieke Ackerstaff of the Department of Head and Neck Surgical Oncology of the Netherlands Cancer Institute, the Department of Otolaryngology of the Academic Medical Center (AMC; Prof. Dr. Wytske Fokkens) and the Departments of MTO and Neonatology (Dr. Ir. Frans de Jongh) of the AMC. AIO is J.K. Zuur, MD. Duration 2003-2007 (Netherlands Cancer Institute projects N04LFV, N04OXY, N05HME).

2. Development and evaluation of a third generation Provox voice prosthesis
Vocal rehabilitation after total laryngectomy with the help of implanted voice prostheses is presently the gold standard to re-establish oral communication after this (often successful) cancer operation. In the Netherlands, there are currently approximately 2500 laryngectomized individuals. The majority of them are using voice prostheses, which act as one-way valves to allow pulmonary air to be used for voicing and at the same time prevent aspiration of fluids into the trachea. These devices have no ‘eternal life’ and need to be replaced, when the one-way valve function deteriorates, leading to insufficient closing and thus to aspiration of fluids. Furthermore, deterioration of the valve may also impair voicing. Therefore, current research is focusing on improvement of durability and physical properties of the present generation voice prostheses. This project is funded by an unrestricted research grant by Atos Medical AB, Sweden. This project is carried out in close collaboration with Dr. Annemieke Ackerstaff and other staff members of the Department of Head and Neck Surgical Oncology of the Netherlands Cancer Institute. Duration since 1987, ongoing (Netherlands Cancer Institute projects N98VOX, N00VOX, M01VOX).

3. Prevention of trismus, swallowing, and speech problems after chemoradiation for advanced head and neck cancer.
Chemoradiation treatment for advanced, inoperable head and neck cancer is increasingly successful in eradicating disease. However, despite the fact that organ preservation is highly likely, function preservation is often still quite poor. The main issues are the development or persistence of trismus and swallowing problems, whereas voicing also can remain impaired. There are indications that early rehabilitation, i.e. starting even before the onset of the therapy can diminish and even prevent some are most of the treatment related problems. Therefore, a prospective, randomized trial is carried out to study, in which standard speech pathology exercises are compared with a dedicated trismus treating device on the possibilities to prevent post treatment trismus and swallowing sequels. Funding Atos Medical AB, Sweden (unrestricted research grant). Co-investigators are Dr. Maya van Rossum and Dr. Ludi Smeele. AIO was Lisette van der Molen, MA. Duration: 2006-2011 (Netherlands Cancer Institute project N05TSP). Thesis defense November 4, 2011.