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Published: Proceedings of the 4th International Symposium. Zurich, No more crimping: the new clip piston à Wengen.
Switzerland, 27 - 30 July 2006. Middle Ear Mechanics in Research and Visiting Professor at HNO-University Hospital Basel, Switzerland
Otology: pp. 237-245. à Wengen D.
DOI: 10.1142/9789812708694_0032
Published: 24th Politzer Meeting 31 August – 4 September 2003, Amster-
275 inserted Clip-Pistons type “ à Wengen” within three years revealed dif- dam, the Netherlands: Selected Abstracts
ficulties in 14.5% of the cases. In those cases it was necessary to make
adjustments to the clip shape (plastic deformation) before insertion due to Objective: Crimping of the stapes prosthesis might result in injury to the in-
the individual dimension of the long incudal process. During 100 middle ear cus. Attachment is often not tight. Facilitated fixation of a stapes prosthesis
surgeries the cross sections of the long incudal processes where the clip is could improve surgery and provide more stable results.
attached was measured. This resulted in data hitherto unknown. By virtue
of a Finite Element Model (FEM) these data were used for optimizing the Method: After development of a unique titanium clip over a seven year
clip shape. Design criteria were a minimal variation of the contact force period (Kurz AG, Dusslingen Germany) and reception of a CE-mark, the
for different cross-sections and to minimize the force necessary to slide the first implantation was performed in September 2000. Full FDA approval
clip over the incudal process. The new clip has a lower stiffness and can was received in June 2002. Up to May 2003 more than 2400 Clip Piston
therefore be applied onto different incus diameters. The lower contact force àWengen have been purchased in several countries around the world.
reduces the risk of arrosion. Due to its optimized shape, the maximal stress
in the clip is lowered preventing plastic deformation during the application Results: Only 60% of the circumference of the incus is touched by the clip
procedure. The application force was decreased by up to 45% depending on permitting adequate mucosal blood supply to the lenticular process. Appli-
the application points. This leads to easy and safe application reducing the cation of the prosthesis is quick and stable. There is no need for crimping
risk of damaging the ossicular chain. anymore. The clip holds precisely in the main axis of movement of the long
process of the incus.
First Experience with a New Stapes Clip Piston in Stapedotomy Conclusion: This new stapes prosthesis facilitates surgery and reduces OR-
time. There is no need for crimping anymore. Acoustic coupling is ideal due
Grolman W., Tange R. A. to the spring action of the self-retaining clip. Most surgeons have switched
entirely to this prosthesis. Long-term results will be needed to prove the
Published: Otology & Neurotology: 2005 July;26(4):595-8 reduction of incus necrosis. In the nearly three year period of observation
DOI: 10.1097/01.mao.0000178132.89353.54 since the first implantation there was no loosening of the clip.
Objecvtive: Hearing results after 23 implantations of a newly designed tita-
nium-clip stapes piston prosthesis (the à Wengen Clip Piston prosthesis) in
patients with otosclerosis were evaluated. This is a new type of stapes piston CLIP PIS T ON MVP
was designed to avoid the crimping onto the incus in stapedotomy. This one
clip fits all designs and enables solid fixation by clicking the prosthesis onto
the long process of the incus without crimping. A New Self-Fixing and Articulated Malleus Grip
Stapedectomy Prosthesis
Study Design: A retrospective pilot study was carried out by microcomput-
er of the preoperative and postoperative audiological results of patients in Häusler R., Steinhardt U.
whom the titanium-clip stapes piston prosthesis was implanted.
Published: Adv Otorhinolaryngol, (2007) Vol 65, 197-201
Setting: Ear, nose and throat department of Academic Medical Center, Uni- DOI: 10.1159/000098807
versity of Amsterdam, Amsterdam, The Netherlands.
®
A new prosthesis for malleus-grip stapedectomy is presented: the Clip
Patients: 23 patients underwent a stapedotomy for hearing improvement Piston MVP according to Häusler. The titanium piston is equipped with a
suffering from otosclerosis. Implantations of a newly designed titanium-clip self-fixing clip mechanism for automatic fixation of the prosthesis on the
stapes piston prosthesis (the à Wengen Clip Piston prosthesis) in patients proximal malleus handle as well as a ball and socket articulation allowing
with otosclerosis were evaluated. easy introduction of the piston at an optimal angle into the oval window
as well as adjustment of the insertion depth. A first series of malleus-grip
Intervention(s): The stapedotomy was performed with the à Wengen Clip stapedectomies performed with the Clip Piston MVP shows a hearing
®
Piston prosthesis. gain of 20 to 50 dB and a residual air-bone gap of ≥ 20 dB in all cases.
In one patient, revision surgery was necessary because of piston ejection
Main outcome measure(s): Pre and postoperative audiograms were used from the oval window. It appears that with the new Clip Piston MVP
®
to evaluate the hearing gain improvement with the new stapes piston. Es- the previously difficult surgery of malleus-grip stapedectomy has become
pecially we looked at the airbone gap closure and the sensorineural hear- straight forward and technically simpler.
ing after the surgical procedure and compared these with the ones before
surgery.
Initial Experience with Titanium MVP Clip Prosthesis
Results: The hearing results showed a closure of the pure-tone average
air-bone gap to within 10 dB in 56.6% of cases (10 of 23 implantations) Singh P. P.
and to within 20 dB in 100% (23 of 23 implantations). A residual air-bone
gap of greater than 20 dB was seen in the present pilot study. Postoper- Published: MEMRO 2006, 4th International Symposium on Middle Ear
ative overclosure of bone-conduction thresholds was discovered only for Mechanics in Research and Otology: Selected Abstracts
the frequency of 2 kHz. Sensorineural hearing loss greater than 10% did
not occur, and there was no decline in the speech discrimination. Introduction: After introduction of stapes surgery malleovestibulopexy
(MVP) was the natural extention of this procedure. Although the hear-
Conclusions: The use of a newly designed titanium-clip stapes piston ing results of stapes surgery were usually excellent, the hearing results of
prosthesis with a diameter of 0.4 mm gives good results in cases of stape- MVP were quite variable. This probably resulted from poor understanding
dotomy for otosclerosis. The titanium-clip design is a new development of middle ear mechanics and usage of the same prosthesis as used for sta-
in the evolution of stapes piston prostheses. Surgical introduction, place- pes surgery. Modification of prosthesis design and technique has resulted
ment, and fixation are not always easy, depending on the anatomy of the in improved hearing outcomes after this procedure.
middle ear and the thickness of the fixation area on the long process of
the incus. Purpose: To evaluate the hearing outcomes of malleovestibulopexy using
titanium MVP clip prosthesis which has recently been introduced.

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