Ranko Rišavi
University of Zagreb
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Featured researches published by Ranko Rišavi.
Journal of Laryngology and Otology | 2001
Jadranka Handžić-Ćuk; Višeslav Ćuk; Miroslav Gluhinic; Ranko Rišavi; Smiljana Štajner-Katušić
Tympanometry was analysed according to cleft type with respect to age in 239 cleft palate patients (57 with bilateral cleft lip and palate (BCLP)), 122 with unilateral cleft lip and palate (UCLP) and 60 with isolated cleft palate (ICP). The frequency of type B tympanograms was 46.5 per cent in the BCLP group, 50.6 per cent in the UCLP group and 58.3 per cent in the ICP group. Type A tympanograms were more frequently observed in older patients (median age 11 years) in comparison to type B (median age five years; p < 0.001) and type C (median age six years; p < 0.001). The total sample showed an age-related decrease in the frequency of type B tympanograms (rs = -0.3942; p < 0.001). The frequency of type A tympanograms increased significantly with age (rs = 0.4263; p < 0.001), whereas type C was not correlated with age. In the UCLP group, the frequency of type B tympanograms decreased with age (rs = -0.4430; p < 0.001), the decrease being faster than in the BCLP group (rs = -0.3186; p = 0.001) and the ICP group (rs = -0.3378; p < 0.0001)). Type B tympanograms had the highest correlation with a hearing loss of 21-40 dB at mean hearing level at speech frequencies (MHLSF) (rs = 0.4574; p < 0.001), a lower correlation with a hearing loss of 11-20 dB (rs = 0.2184; p = 0.02) and the lowest correlation with hearing loss above 40 dB. At the ages of one to three, the frequency of type B is higher in UCLP patients than in the BCLP and ICP groups, decreasing at seven to 12, increasing again at 13 to 15, and thereafter showing a continuous decrease. In the BCLP group, the frequency of type B increased significantly at the ages of four to six and then decreased continuously from seven to 18. In ICP patients, the changes in the frequency of type B with age are not significant until the age of 15; at the age of seven, it is higher than in the BCLP and ICP groups. The type C tympanogram is not typically found in cleft palate patients and its frequency is not correlated with age. It can be presumed that each type of cleft lip and palate, due to its characteristic conditions in the epipharynx, will favour a different mode of pathophysiological development of middle-ear disease.
International Journal of Pediatric Otorhinolaryngology | 1996
Jadranka Handžić-Ćuk; Višeslav Ćuk; Ranko Rišavi; Damir Katušić; Smiljana Štajner-Katušić
Tonal audiometry was used to compare hearing levels in patients with bilateral cleft lip and palate (BCLP) (57 patients). unilateral cleft lip and palate (UCLP) (124 patients) and isolated cleft palate (ICP) (62 patients), and according to age groups. Patients with isolated cleft palate showed greater improvement in hearing level with age than patients with UCLP and BCLP; as adults they showed the lowest frequency of ears with hearing level of less than 40 dB, and the highest frequency of ears with hearing levels of 11-20 dB. Patients with BCLP had a higher frequency of ears with a hearing level of 21-40 dB during early childhood and adult age than patients with ICP. Patients with UCLP and BCLP showed a slower decrease with age in the frequency of ears with hearing loss than patients with ICP; the hearing level in patients with UCLP and BCLP improved only in groups with hearing levels of 21-40 dB, while those with hearing levels above 40 dB showed no significant improvement with age.
American Journal of Otolaryngology | 1995
Ivica Klapan; Filip Čulo; Josip Čulig; Željka Bukovec; Stjepan Simović; Ćuk Višeslav; Ranko Rišavi; Bumber Željko; Nikola Šprem; Vukoja Miljenko
PURPOSE The etiology of sinonasal polyps is sometimes obscure. This study was undertaken to evaluate the potential role of arachidonic acid metabolites (AAm) on recurrent polyposis. MATERIALS AND METHODS Tissue production of prostaglandin E2 (PGE2), 6-keto-prostaglandin F1-alpha (PGI2), thromboxane A2 (TxA2), and leukotriene C4 (LTC4) by nasal mucosa was determined by radioimmunoassay in 27 patients with sinonasal polyposis (SNp) and in 10 volunteers. RESULTS The group of patients with SNp with the evidence of recurrences in postoperative period (Group 1) showed significantly lower PGE2 concentrations than group of patients with SNp recurrences (Group 2). The differences in concentrations of PGI2 in mentioned groups were insignificant. In comparison with other groups, a group of patients who underwent surgery several times for SNp (Group 4) had a higher mean TxA2 concentration. The LTC4 concentrations were the highest in groups of patients where SNp recurrences were observed. When the incidence of polyposis recurrences (within 18 months after surgery) was correlated with the level of LTC4 production at the time of surgery, the rate of recurrence was significantly higher in patients with increased LTC4 level than in those with normal LTC4 levels. CONCLUSIONS LTC4 might have a prognostic value. The possible role of AAm in occurrence of SNp is apparent and suggests possible role for medical intervention.
Acta Oto-laryngologica | 1998
R. Subotić; Ranko Mladina; Ranko Rišavi
Bony fixation of the malleus seems to be one of the most controversial clinical entities among various congenital disorders of the auditory ossicles. According to various theories, it could be caused by trauma, chronic infection of the ear, otosclerosis or even development failures in the tympanic cavity itself. Histological analysis of 1,108 temporal bones showing a normal middle ear structure was performed. All bones were cut in serial sections of 20 microns. Audiograms and the data on ear trauma or chronic infection were analysed from case histories belonging to each bony specimen. Bony fixation of the malleus was found in 14 cases. It was almost always unilateral. The most frequent site of the fixation was the lateral epitympanal wall. The forms of fixation differed from a thin bony lamella to a solid bony bridge. The mallear ligaments were not involved in any case. No relationship to chronic ear infection, ear trauma or otosclerosis was found. Only a slight conductive hearing impairment up to 20 dB was recorded in 6 out of 14 cases. The most probable predisposing anatomical factors for the onset of the bony fixation of the malleus and the most recent preoperative diagnostic possibilities are discussed.
Journal of Laryngology and Otology | 1996
Jadranka Handžić-Ćuk; Višeslav Ćuk; Ranko Rišavi; Vladimir Katić; Damir Katušić; Marijo Bagatin; Smiljana Štajner-Katušić; Damir Gortan
Hearing loss was studied in 22 patients with Pierre Robin syndrome (PRS) aged three to 12 years (median 5.0 years). The results were compared to those obtained in 62 patients with isolated cleft palate (ICP) aged one to 27 years (median 5.5 years). Hearing loss was more frequently found in PRS (73.3 per cent) than in ICP (58.1 per cent) patients (p = 0.02). PRS patients had more ears with moderate (21-40 dB) and severe (> 40 dB) hearing loss, disturbing their social contact, with no tendency to normalization with age (Spearman r = 0.065). In contrast to PRS, ICP patients showed a significant tendency to hearing level normalization with ageing (Spearman r = -0.453; p = 0.001). Planigraphs of temporal bones showed inadequately developed pneumatization of the mastoid bone in all PRS patients and in most ICP patients. No malformation of the inner or middle ear was found in either group. PRS patients have a significantly higher risk of conductive hearing loss than those with ICP. Use of tympanostomy (ventilation) tubes is therapy of choice in patients with Pierre Robin syndrome, and it should be introduced as early as possible, even at the same time as palatoplasty.
Orbit | 2001
Ivica Klapan; Ante Barbir; Ljubimko Šimičić; Ranko Rišavi; Nada Bešenski; Željko Bumber; Neda Stiglmayer; Slavko Antolic; Saša Janjanin; Mario Bilić
The main goal of our dynamic 3D computer-assisted reconstruction of a metallic retrobulbar foreign body following orbital injury with ethmoid bone involvement was to use 3D-information obtained from standard computed tomography (CT) data to explore and evaluate the nasal cavity, ethmoidal sinuses, retrobulbar region, and the foreign body itself by simulated dynamic computed visualization of the human head. A foreign body, 10 × 30 mm in size, partially protruded into the posterior ethmoidal cells and partially into the orbit, causing dislocation and compression of the medial rectus muscle and inferior rectus muscle. The other muscles and the optic nerve were intact. Various steps were taken to further the ultimate diagnosis and surgery. Thin CT sections of the nasal cavity, orbit and paranasal sinuses were made on a conventional CT device at a regional medical center, CT scans were transmitted via a computer network to different locations, and special views very similar to those seen on standard endoscopy were created. Special software for 3D modeling, specially designed and modified for 3D C-FESS purposes, was used, as well as a 3D-digitizer connected to the computer and multimedia navigation through the computer during 3D C-FESS. Our approach achieves the visualization of very delicate anatomical structures within the orbit in unconventional (non-standard) sections and angles of viewing, which cannot be obtained by standard endoscopy or 2D CT scanning. Finally, virtual endoscopy (VE) or a ‘computed journey’ through the anatomical spaces of the paranasal sinuses and orbit substantially improves the 3D C-FESS procedure by simulating the surgical procedure prior to real surgery.
International Journal of Pediatric Otorhinolaryngology | 1998
Ranko Rišavi; Ivica Klapan; J Handžić-Ćuk; T Barčan
Between 1993 and 1996 we operated on 50 children with one of the following surgical indications: 17 children with a complication of acute rhinosinusitis and the propagation of the process towards the orbit (periorbitis), six children with an ethmoid and sphenoid foreign body (shrapnels shells), 11 children with an antrochoanal polyp, four children with nasal polyposis in cystic fibrosis and 12 children with chronic rhinosinusitis after 2-4 acute reinfections. The surgery was done under endotracheal anesthesia with hypotension. CT axial and coronal tomograms were done during the preoperative treatment. During the 2 weeks preoperative treatment, the patients with polyposis and antrochoanal polyps were treated with 4-8 mg of cortisone per os or i.m., and also with Fluticasone Propionate 100 mg twice a day and antibiotics in chronic and acute rhinosinusitis. The childrens age was between 7 and 15 years. In the patients with nasal polyposis and antrochoanal polyps (n = 15) post-operatively, we had four cases of synechiae, recurrent polyposis in two and antrochoanal polyps in two cases.
Otolaryngology-Head and Neck Surgery | 2002
Ivica Klapan; Ljubimko Šimičić; Ranko Rišavi; Nada Bešenski; Karlo Pasarić; Damir Gortan; Saša Janjanin; Dag Pavic
One of the main objectives of our 3-dimensional (3D) computer-assisted functional endoscopic sinus surgery was to design a computer-assisted 3D approach to the presurgical planning, intraoperative guidance, and postoperative analysis of the anatomic regions of the nose and paranasal sinuses. Such an extremely powerful approach should allow better insight into the operating field, thereby significantly increasing the safety of the procedure. The last step to implementing the technology in the operating room was to connect the computer workstations and video equipment to remote locations by using a high-speed, wide-bandwidth computer network. During patient preparation, the surgeon in the operating room consulted remote experienced and skillful surgeons by viewing CT images and 3D models on computer workstations. The surgeon and consultants used software for CT image previews and 3D model manipulations on top of collaboration tools to define the pathosis, produce an optimal path to the pathosis, and decide how to perform the real surgical procedure. With tele-flythrough or tele-virtual endoscopy rendered through the use of 3D models, both surgeons can preview all the characteristics of the region (ie, anatomy, pathosis) and so predict and determine the next steps of the operation. This ensures greater safety thanks to the operation guidance and reduces the possibility of intraoperative error. The duration of the teleconsultation is thus shortened, which may prove the greatest benefit of tele-3D computer-assisted surgery. If this method were used, clinical institutions would spend less money for telesurgical consultation.
Otolaryngology-Head and Neck Surgery | 1999
Ivica Klapan; Ranko Rišavi; Ljubimko Šimičić; Stjepan Simović
Image-Guided Functional Endoscopic Sinus Surgery GARTH T OLSON MD (presenter); MARTIN J CITARDI MD; Saint Louis MO Introduction: Although rhinologic surgeons are increasingly applying image-guided surgery (IGS) technology for endonasal procedures, the ultimate utility of IGS for endoscopic sinus surgery has been the subject of considerable discussion. Objective: (1) To provide the framework for the application of IGS (including software-based CT image analysis) into preoperative planning so that specific anatomic assessments may be performed. (2) To develop intraoperative strategies for the execution of this preoperative planning. Study Design: Retrospective review. Methods: Between October 1, 1997, and December 31, 1998, the StealthStation (Sofamor Danek, Memphis, TN) was employed in 61 functional endoscopic sinus surgery cases. The indication for surgery in all instances was chronic rhinosinusitis refractory to medical management. Preoperative CT scans were obtained according to a specific protocol. The StealthStation software package was used to review all CT scans prior to surgery. Registration with anatomic fiducials, supplemented by contour mapping registration, was employed. Specific cases serve to illustrate the utility of IGS. Results: In all cases, localization accuracy was estimated to be within 2 nun or better. The StealthStation was utilized for both CT image review and intraoperative localization. From a surgical anatomy viewpoint, IGS was especially useful in the frontal recess, in the sphenoethmoid region, in the posterior ethmoid system, and at the skull base. In addition, IGS was deemed helpful in situations where the surgical anatomy was altered by previous surgery and extensive inflammatory disease {such as sinonasal polyposis, allergic fungal sinusitis, and pansinusitis). Conclusion: IGS technology should be routinely integrated into functional endoscopic sinus surgery. The resultant paradigm of image-guided functional endoscopic sinus surgery will serve to increase surgical effectiveness and decrease overall surgical morbidity.
Journal of Telemedicine and Telecare | 2002
Ivica Klapan; Ljubimko Šimičić; Karlo Pasarić; Anto Vlahušić; Ranko Rišavi; Vlado Sruk; Dragan Schwarz; Jadranko Barišić
We have carried out three-dimensional, computer-assisted, functional endoscopic sinus telesurgery. Surgeons at different locations up to 300 km apart could not only see and transfer video images but also transfer three-dimensional computer models and manipulate them in realtime during surgery. Two different approaches were used. In the first telesurgery procedure we used M-JPEG compression and transmitted the data using fibre optic connections (ATM OC-3) at a bandwidth of 155 Mbit/s. In the second telesurgery procedure video images were transmitted over four E1 digital lines, amounting to about 8 Mbit/s of bandwidth, with better compression standards, such as MPEG1 and 2. We found that MPEG2 video compression produced the best picture quality for the operating field and endoscopic cameras. For conferencing and consultation between two or more connected sites during the surgery, we used JPEG and MPEG1 video compression with audio. The main feature of our three-dimensional telesurgery was the use of three-dimensional modelling of the operative field. This is important for emergency surgical interventions. We do not advocate that inexperienced surgeons operate on patients, not even with the guidance of a remote surgeon. However, three-dimensional telesurgery may become very valuable for experienced surgeons in the future.