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S G Lesinski

Publications and source records attributed to S G Lesinski.

At least 19 recordsLinked to original sources
PubMed1993

Carbon dioxide lasers for otosclerosis.

Over the past eight years, the senior author (SGL) has sought the ideal microsurgical laser for otosclerosis surgery. This quest required learning the principles of laser physics and of the interactions of light with matter. Rather simple thermocouple experiments were performed in the laboratories of the Midwest Ear Foundation (MEF) to confirm some of what was predicted from these principles. More sophisticated transmission spectroscopy experiments were performed at the Massachusetts Institute of Technology (MIT) to evaluate which electromagnetic wavelengths are best absorbed by collagen and bone. MIT's spectroscopy studies paralleled MEF's thermocouple data. CO2 laser energy (10.6 microns) is nearly completely absorbed by collagen and bone, whereas visible argon and KTP laser energy (0.5 micron) is poorly absorbed. Despite the better optical precision of visible lasers, the author chose the CO2 laser for stapedectomy revision and stapedotomy, because long infrared electromagnetic energy has vastly superior tissue absorption characteristics for these procedures. With the development of I. L. Med's Unilase, the otologic surgeon now has a CO2 laser with optical precision and convenience approaching that of visible lasers. Clinical studies of 102 consecutive CO2 laser stapedectomy revisions show that in 92% of patients, hearing was significantly improved with the new CO2 laser revision techniques. Nearly half of these patients had undergone one or more previous, unsuccessful, nonlaser revisions. For primary otosclerosis, CO2 laser stapedotomy has simplified a technically difficult operation while significantly reducing mechanical trauma to the inner ear. Most gratifying to the senior author is that after approximately 450 consecutive CO2 laser operations for otosclerosis, no patient has experienced significant postoperative sensorineural hearing loss (greater than 15 dB; mean 500, 1000, 2000, 3000 Hz). This fact alone has justified our theoretical and laboratory efforts to find the safest laser for otosclerosis surgery.

Carbon Dioxide↗
PubMed1990

Lasers for otosclerosis--which one if any and why.

Laboratory stapedotomy and stapedectomy revisions were performed in human temporal bones while pyroelectric wave energy analyzers and ultrasensitive thermocouples measured energy absorption at the stapes footplate and in the vestibule. Analysis of these data shows that the visible lasers (argon and KTP-532) possess ideal optical properties and precision for otosclerosis surgery but conversely have less than ideal tissue characteristics. The CO2 laser possesses ideal tissue characteristics. Recent advances in optical engineering and pulsing the energy have increased the precision of this laser to now provide the accuracy required for delicate microsurgery. Two clinical studies analyze the long-term hearing results and complications in patients who had undergone CO2 laser stapedectomy revision (59 patients) and CO2 laser stapedotomy (153 patients). The advantages that these laser techniques provide over conventional surgery methods are discussed.

Equipment Design↗
PubMed1989

Lasers for otosclerosis: CO2 vs. Argon and KTP-532.

The concept of using laser energy to perform stapedotomy and stapedectomy revision is an attractive one. Precision of vaporizing a perfectly round 0.6- to 0.8-mm hole in the stapes footplate, regardless of its thickness or degree of fixation, would introduce an elegant simplicity to a sometimes difficult operation while eliminating mechanical trauma to the inner ear. When revising a previously failed stapedectomy, lasers should enable the otologic surgeon to atraumatically vaporize the obliterating oval window tissue and thus precisely diagnose the cause of the failure. A laser stapedotomy could then be performed in the membranous oval window, thus minimizing the risk of recurrent prosthesis migration. To accomplish these objectives, lasers must possess physical properties which permit the precise controlled delivery of laser energy to the microscopic operative field. Tissue characteristics of this laser energy should permit the vaporization of the stapes footplate or oval window soft tissue without thermal effect to the vestibule and without passing through the perilymph to damage the delicate structures of the inner ear. Two types of lasers have been successfully used for otosclerosis surgery: the visible lasers (Argon and KTP-532) and the invisible CO2 laser. This paper explores relative merits and disadvantages of each. The visible lasers possess ideal optical properties for microsurgery and, until recently (1984), were the only group of lasers optically precise enough for safe use on the oval window. Unfortunately, the short wavelength of these visible lasers (0.5 mu) impart tissue properties which are less than ideal for otosclerosis surgery. Visible laser is only partially absorbed by the white stapes footplate and readily passes through the perilymph to be absorbed by pigmented tissue of the inner ear (blood vessels, neuroepithelium, etc.). Therefore, the Argon and KTP-532 lasers should be used with caution while performing stapedotomies. Visible lasers should not be used for stapedectomy revisions since direct application of visible laser energy to the open vestibule produces dramatic temperature rises (up to 175 degrees C) in the vestibule at the level of the utricle and saccule. The long wavelength of the invisible CO2 laser (10.6 mu) imparts many optical problems which limit its precision for microscopic surgery. Until recently, the CO2 laser was too inaccurate for otosclerosis engineering advances for CO2 microsurgery. A newly designed microslad optical delivery system could deliver a 0.3-mm spot size CO2 beam at 250-mm focal length which was satisfactorily par-focal and coaxial with the aiming HeNe beam.(ABSTRACT TRUNCATED AT 400 WORDS)

Argon↗
PubMed1989

CO2 laser stapedotomy.

This clinical study was preceded by two laboratory experiments. The first experiment compared temperature changes in the vestibule while vaporizing a 0.6-mm stapedotomy with Argon, KTP-532, and CO2 lasers. Data demonstrated that the CO2 laser possesses superior tissue characteristics for stapedotomy. In the second experiment safe energy parameters were established for various Sharplan CO2 laser models. Using these safe power settings, 153 consecutive CO2 laser stapedotomies were performed under local anesthesia. No patient experienced intraoperative dizziness during or immediately following the application of the CO2 laser to the stapes footplate. Long-term postoperative hearing results demonstrated that 87% of the patients maintained an air/bone gap to within 10 dB and 94% maintained an air/bone gap to within 15 dB (mean follow-up 32 months). No patient incurred a significant sensorineural hearing loss (greater than 10 dB) in the speech range. Four patients developed a perilymph fistula (three immediate and one delayed) and fluctuating sensorineural hearing loss, but all were successfully repaired without significant permanent nerve deafness. At 4,000 Hz, five patients lost 20 dB and two patients dropped 40 dB compared with preoperative levels. Postoperative complications included four perilymph fistulas, two prostheses displaced from the stapedotomy opening, one fixed prosthesis, and one fixed incus. Seven of eight of these complications were successfully revised. At the time of this writing, 6/153 patients have a persistent conductive hearing loss greater than 20 dB and have not been revised. Using appropriate energy parameters, the CO2 laser provides a safe, efficient microsurgical tool for performing stapedotomy simply and with minimum inner ear trauma.

Carbon Dioxide↗
PubMed1989

CO2 laser for otosclerosis: safe energy parameters.

Safe energy parameters for each Sharplan CO2 laser model (734, 1040, 1100A) were established in the laboratory. Ultrasensitive pyroelectric detectors analyzed the precise energy package delivered to the operative field with each of these power setting. Subsequently, 0.6-mm stapedotomy and stapedectomy revisions were performed under simulated operating room conditions while measuring temperature changes in the vestibule with a thermocouple. Table I illustrates safe energy settings for each of the Sharplan CO2 models tested. These power settings produced no more than 0.3 degrees C temperature rise in the vestibule during stapedotomy, and no more than 0.5 degrees C during stapedectomy revision. Following these guidelines, the CO2 laser was then employed to perform stapedotomy and stapedectomy revisions in otosclerosis patients. In over 200 consecutive operations performed under local anesthesia with the CO2 laser, no patient became dizzy intraoperatively while the CO2 laser was applied to the stapes footplate or the oval window neomembrane, confirming the lack of significant caloric effect to the inner ear at these energy settings. More importantly, no patient has yet experienced significant sensorineural hearing loss in the speech range.

Carbon Dioxide↗
PubMed1986

Homograft (allograft) tympanoplasty update.

If homograft tympanoplasty is to be of value, specific instances in which homograft tympanic membrane, malleus, and incus (TMMI) provide significant hearing and anatomical advantages over standard techniques should be identified. This author has performed 305 homograft tympanoplasties limited to the reconstruction of the severely damaged middle ear. Indications include: previous failure with standard tympanoplasty techniques; high risk of anatomic or hearing failure with standard techniques (total perforation with absent malleus, slag burns); reconstruction of radical mastoidectomy; congenital aural atresia. The first 125 consecutive homograft tympanoplasties were reported in 1982. One hundred eighty additional homograft tympanoplasties have been performed since then. In the past 3 years the anatomic success rate has risen to 97% (174/180) with refinement of surgical techniques. Eighty-five percent of all patients have maintained an average air-bone gap of 25 dB or better. Formalin preserved homograft tympanic membranes with attached malleus offer significant advantages over standard tympanoplasty techniques in these specific indications.

Ear↗
PubMed1984

Reconstruction of hearing when malleus is absent: TORP vs. homograft TMMI.

To study the most appropriate ossicular reconstruction of patients with an absent malleus, a comparison was made utilizing a homograft tympanic membrane with attached malleus and shaped incus (TMMI) columella and the alternative use of underlay fascia tympanoplasty with a cartilage covered TORP. Forty-six patients were reconstructed with a homograft TMMI and 38 with cartilage covered TORP and underlay fascia technique; 4.5 years postoperatively, 84% of those patients reconstructed with a homograft TMMI maintained an average A/B gap of 25 dB or better. Though 1 year postoperatively the TORP hearing results were satisfactory, only 18% of the TORP patients maintained a hearing level within 25 dB A/B gap at 4 years postoperatively. Primary causes of failure of the TORP were instability with migration off the stapes footplate, protrusion or extrusion through the TM and finally, long-term softening and bending secondary to biodegradation of the Plastipore. The discouraging long-term hearing results found in the TORP patients in this study confirm similar findings reported in 1982 by Smyth in a 5 year follow-up on 116 TORP patients.

Cholesteatoma↗
PubMed1983

Homograft tympanoplasty in perspective. A long-term clinical-histologic study of formalin-fixed tympanic membranes used for the reconstruction of 125 severely damaged middle ears.

This seven and a half year clinical-histologic study evaluates the effectiveness of buffered, formaldehyde-fixed homograft tympanic membranes for reconstructing the severely damaged middle ear in 125 consecutive patients. Indications for use of homograft tympanoplasty were limited to those cases in which standard tympanoplasty had already failed to produce a satisfactory hearing or anatomic result (i.e., recurrent perforations or draining radical mastoidectomy cavity), or to those cases in which there was a high risk of unsatisfactory result with standard tympanoplasty techniques (i.e., total perforation with absent malleus or congenital aural atresia). Anatomic data was documented with serial postoperative photomicrography. Audiograms were performed at yearly intervals and long-term hearing results were analyzed. Histologic studies were performed on 2 homograft tympanic membranes removed 6 months and 6 years postoperatively. Postoperative photographs of the healing donor tympanic membrane and histologic studies confirmed that the homograft collagen attracts host angioblasts, fibroblasts and epithelial cells. The initial inflammatory response (primarily lymphocytic) subsides and the host produces collagen and elastin fibers interspersed among the donor collagen. Gradually the donor collagen is resorbed. At the completion of this study, 95% (119/125) of the homograft tympanoplasties are currently intact. There were 13 immediate postoperative perforations, but 11 were repaired with a second stage underlay fascia tympanoplasty. Long-term hearing results were analyzed according to the type of ossicular reconstruction employed (mean follow-up 4 years). In 87 patients with chronic otitis media, 94% of the type I repairs maintained an air-bone gap of 25 dB or less, 85% of the type II, and 81% of the type III. Forty-four patients presented with an absent malleus and absent tympanic membrane and were reconstructed with a homograft tympanic membrane with attached malleus and a shaped incus columella. At 4 years postoperatively, 83% of these patients maintained an average air-bone gap of 25 dB or better. A similar group of 38 patients presenting with absent malleus, incus, and stapes were reconstructed with isograft temporalis fascia and a cartilage covered TORP. Only 18% of the TORP patients maintained an air-bone gap of 25 dB 4 years postoperatively. Thirty-three patients with draining radical mastoidectomy cavities were reconstructed; 97% (32/33) had a dry, self-cleansing ear with no activity restriction. Only 59% maintained an air-bone gap closure of 25 dB or better in the long-term follow-up; 30% (10/33) developed persistent eustachian tube dysfunction, usually in the second through fourth postoperative years.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1982

Complications of homograft tympanoplasty.

The use of a homograft tympanic membrane with an attached malleus has provided an excellent alternative for reconstructing the severely damaged middle ear. I have limited homograft tympanoplasty to four specific indications: previous failure of standard tympanoplasty techniques, high risk of failure (total perforation, absent malleus, slag burns), reconstruction of radical mastoidectomy, and congenital aural atresia. Homograft tympanoplasty has provided a 94 per cent incidence of anatomic success in these severely damaged middle ears. Closure of the air-bone gap to within 25 dB. was accomplished in 85 per cent of these patients. Complications must be viewed in the perspective of the extensive disease in the middle ear that was being reconstructed. Only meticulous attention to surgical technique and postoperative care will provide the successes described by Wehrs, Marquet, Perkins, and others. The otologic surgeon is urged to observe the surgical techniques of homograft tympanoplasty rather than merely read about it. I believe that the transplant tympanic membrane should be used only when it provides an advantage over standard grafting techniques. Underlay fascia tympanoplasty yields excellent results in the majority of eardrum reconstructions. A final word about homograft tympanic membrane and ossicles. Although several "banks" for ear tissue are available in the United States, there are few established guidelines that these banks are required to follow. The otologic surgeon who uses homograft tissue must be guaranteed that the biologic product he is implanting in his patient is sterile, is anatomically perfect, has been stored in a chemically stable preservative, and has proven biologic effectiveness. Ear banks should be managed by surgeons who are using that tissue in their own patients, thus monitoring the tissue's quality. Each bank has a responsibility to donors, recipients, and surgeons to maintain the highest laboratory standards that will guarantee the quality of its product. Since there is no regulating agency, the practicing physician should insist that these standards for processed homograft ear tissue be maintained.

Cholesteatoma↗
PubMed1980

Does the Silastic Eustachian Tube prosthesis improve eustachian tube function?

This clinical study attempts to evaluate the effectiveness of Eustachian tube function in 30 ears, 11-29 months after insertion of the Silastic Eustachian tube prosthesis (SETP). Indications for the SETP were limited to persistent Eustachian tube dysfunction. Preoperatively, 13 patients had intact tympanic membranes with persistent serous otitis media. Seventeen patients underwent tympanoplasty and demonstrated persistent serous otitis media in the opposite ear. Postoperatively, aeration of the middle ear was evaluated by tympanometry, microscopic examination, and myringostomy. Microphotographs demonstrate the state of the middle ear. Histology of the middle ear mucosa was obtained in a few cases. Ninety-six percent of the ears with an SETP demonstrated confirmed persistent Eustachinan tube dysfunction beginning an average of six months after insertion. Complications were common.

Adult↗
PubMed1976

Hemilaryngectomy for T3 (fixed cord) epidermoid carcinoma of larynx.

This clinicopathologic study was undertaken to determine whether true vocal cord fixation produced by epidermoid carcinoma is an absolute contra-indication to treatment by hemilaryngectomy. In a consecutive series of 114 hemilaryngectomies performed at McMillan Hospital (1960-1967) for previously untreated epidermoid carcinoma, 18 patients had fixation of the involved true vocal cord. Each hemilaryngectomy specimen (serial step sections in the longitudinal plane) was re-examined to ascertain the cause of vocal cord fixation; the adequacy of margin; and the presence of blood vessel, nerve sheath and cartilage invasion. Clinical follow-up on each patient was current through December, 1972 (5-12 years postop). All of these cases were seen initially by one of the authors (J.H.O.). Serial sections revealed that true vocal cord fixation was caused by muscle invasion in 14 of the 18 patients. "Positive margins" were present in eight patients but no immediate treatment was given. Two of these patients developed biopsy proven local recurrences, and both were cured with Co60 irradiation. Among the 18 patients with T3 epidermoid carcinoma treated by hemilaryngectomy: a. Three local recurrences developed, all in the anterior commissure. Two were cured with irradiation. The third had a laryngectomy but died from persistent cancer. b. Two patients developed cervical metastases (without local recurrence), and one was salvaged with radical neck dissection. c. Four patients died of other causes, cancer free, three to five years postoperatively. Of the 14 determinant patients, two patients died of cancer. Twelve (85 percent) were alive and free of cancer five years postoperatively. Two had received full course irradiation; one had a radical neck dissection, and all 12 had a functioning larynx. When Ogura's patients are added to the reports of other hemilaryngectomies performed despite true vocal cord fixation (Leroux-Robert [1950] 18/24, Kirchner, Som [1971] 13/19), a determinant salvage rate of 78 percent can be expected. True vocal cord fixation is generally caused by invasion of the vocalis muscle and thus may be well encompassed by a hemilaryngectomy. The precise anatomical limits of the lesion should dictate the type of surgery required for cure.

Carcinoma, Squamous Cell↗
PubMed1975

The significance of positive margins in hemilaryngectomy specimens.

This clinicopathologic study was undertaken to determine the meaning of surgical margins "involved" with carcinoma. The fate of hemilaryngectomy patients whose specimens had this finding was comparared with that of patients who had "uninvolved" margins. A consecutive series of 111 hemilaryngectomies performed for previously untreated invasive epidermoid carcinoma was analyzed. Serial step sections in a longitudinal plane were available for re-examination and re-evaluation of the surgical margins in each case. Clinical follow-up on every patient was current through 1972. Thirty-nine patients had cancer involvement of a margin in the hemilaryngectomy specimen. None of these patients received any immediate therapy but were followed only. Seven of these patients (18 percent) subsequently developed a biopsy proven local recurrence. Four of the 72 patients (6 percent) with uninvolved margins developed a local recurrence. The site of the positive margin in the specimen was compared with the clinical site of recurrence. The seven local recurrences in patients with positive margins were treated with full course irradiation or total laryngectomy. All of these patients are alive and free of cancer or have died of other causes without evidence of cancer. Of the four local recurrences in patients with negative margins one died of cancer; two are living and well, and one died of other causes. This study provides evidence to support the conservative management of those hemilaryngectomy patients who have involved margins in the resection specimen. No immediate treatment is required. Careful follow-up is indicated with 18 percent chance of clinical recurrence. These biopsy proven recurrences can then be successfully treated with total laryngectomy or full course irradiation. Utilizing this approach none of the 39 patients with involved margins died of cancer in the 5 to 12-year follow-up period.

Carcinoma, Squamous Cell↗
PubMedDate not supplied

Why not the eighth nerve? Neurovascular compression--probable cause for pulsatile tinnitus.

Carotid arteriograms on three patients with unilateral pulsatile tinnitus demonstrated an ipsilateral atypical trigeminal artery extending from the cavernous portion of the internal carotid artery to form the posterior inferior cerebellar artery. Illustrations and a dissection of a human fetus with a similar finding show this artery crossing the cochlear nerve near its insertion in the pons. Evidence is presented suggesting that neurovascular compression of the eighth nerve is the source of pulsatile tinnitus in these patients.

Adult↗