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J Zenk

Publications and source records attributed to J Zenk.

At least 19 recordsLinked to original sources
PubMed2000

[Diagnosis and therapy of pseudotumors of the orbits].

Orbital pseudotumor is a nonspecific inflammatory process of unknown etiology that can be divided histopathologically into three basic types: granulomatous, lymphoid, and sclerosing. Between 1995 and 1998, 12 patients with pseudotumor orbitae were treated in the ENT Department of the University of Saarland. Histopathological examination showed granulomatous type of pseudotumor in six, lymphoid in three, and sclerosing in three patients. In seven cases the pseudotumor orbitae were medially located and in four cases laterally. In one patient nearly all orbital structures were infiltrated. Diagnostic biopsy was taken endonasally in six cases, via medical orbitotomy in two cases, and via lateral orbitotomy in four cases. Due to their good delimitation lymphoid and sclerosing tumors were extracted completely during diagnostic biopsy and patients were free of complaints after a few weeks. The six patients with granulomatous pseudotumor were treated primarily with steroids after the diagnosis had been definitely confirmed by histology. In three of those six cases a second course of steroid therapy had to be given, with positive results in two cases. Follow-up was between 6 and 28 months (mean 16 months). There were no postoperative complications. The clinical and radiographic presentation of the pseudotumors can vary greatly. Therefore, the differential diagnosis of specific infections or neoplasms can only be established through diagnostic biopsy. Different rhinosurgical approaches provide clear biopsy results and in some cases the pseudotumor is even completely removed.

Adult↗
PubMed2000

The influence of noise on blood flow in the basilar artery (BA) - measurements with transcranial color-coded duplex sonography (TCCD).

Acoustic stimuli are being reported as a cause of changes in resistance in the basilar artery (BA). It was the aim of this study to investigate this effect under standardized conditions dependent upon the intensity of the evoking stimulus. Twenty healthy subjects with normal hearing (male/female 14/6; mean age 26.4 years) were exposed to 'pink noise' for periods of 2 min at 75, 85 and 95 dB(A). Parallel to this, the Doppler spectrum of the BA and both the Pourcelot resistance index and the Gosling pulsatility index were measured by means of transcranial color-coded Doppler sonography. In comparison with the base value (at rest) a significant increase in resistance was noted during noise exposure. The noise-induced resistance changes could be interpreted as a consequence of changes in activity of the various centers of the auditory pathway and cerebral function. Further animal experiments may prove the connection between BA blood flow and resistance and their changes depending on different acoustic stimuli or different hearing pathophysiology.

Acoustic Stimulation↗
PubMed1999

In vitro tissue effects of a combined Ho:YAG/Nd:YAG laser: sprinkling of tissue fragments by Ho:YAG laser light may be problematic for oncological interventions.

BACKGROUND AND OBJECTIVE: Surgery of soft tissue, for example, of the tongue or the liver, requires a cutting and coagulating device. Therefore, a combined Ho:YAG/Nd:YAG laser providing the laser beam of both systems together in one bare fiber seems to be useful. STUDY DESIGN/MATERIALS AND METHODS: We studied the effect of such a laser system in vitro on tongues of pigs. RESULTS: Combined application of both lasers results in vitro in a thicker coagulation zone in soft tissue (tongue). Tissue fragments possibly containing vital cells are sprinkled by the pulsed energy of the Ho:YAG laser up to a distance of 20 cm. CONCLUSION: Using the pulsed Ho:YAG laser for oncologic interventions seems to be problematic. Combined laser effect in vivo may result in better hemostasis.

Animals↗
PubMed1999

[Clinical and diagnostic findings of sialolithiasis].

INTRODUCTION: Sialolithiasis is one of the most common diseases of the salivary glands. Within the scope of a retrospective analysis we report on our clinical and diagnostic findings in the largest patient group suffering from sialolithiasis reported in literature. MATERIAL AND METHODS: Between 1987 and 1997, data from 635 patient histories and follow-up examinations were systematically collected and analysed to look for typical symptoms of sialolithiasis, locations of stones and possible risk factors. RESULTS: Sialoliths predominated among patients aged 30 and 70 years, with no male/female predilection. A total of 78.9% of all calculi were detected in the submandibular ducts and 21.1% in the ducts of the parotid glands. The sublingual gland and the smaller salivary glands were not affected. A simultaneous stone disease of the urinary tract or the bile duct system occurred by chance (4.3%). Even regular medication in cases of other systemic diseases cannot be considered cofactors in pathogenesis. CONCLUSION: Diagnosis of sialolithiasis is the result of careful consideration of patient histories demonstrating typical symptoms and clinical examination. Sonography is the first choice of imaging. Pathogenesis of sialolithiasis seems to be based on local factors within the salivary ducts and glands.

Adolescent↗
PubMed1999

[Hiccup].

Hiccup is defined as involuntary contractions of the diaphragm and the auxiliary respiratory muscles, mostly in irregular series, followed by glottic closure, thereby producing a typical "hiccupping" inspiration. This is a physiologic phenomenon, which already exists in utero. Hiccup is believed to be a gastrointestinal reflex; however, function and the reflex arch are hypothetical. Acute hiccup is distinguished from pathological, chronic hiccup, defined by a duration executing 48 h, or recurrent episodes. Among approximately 100 causes for hiccup, the most common are located in the gastrointestinal tract, with gastro-esophageal reflux as the most important. While the respiratory effect is generally negligible, alkalosis may ensue in tracheotomized patients due to hyperventilation. A stepwise management plan for patients with hiccup is presented. If simple physical maneuvers and causal therapy fail, or causal therapy is impossible, the treatment of choice is medical, with baclofen. Interruption of the reflex arch may be causal therapy or be considered as a last resort.

Adult↗
PubMed1998

[Long-term results of extracorporeal peizoelectric shock wave lithotripsy of parotid stones].

OBJECTIVE: To evaluate prospectively the recently developed method of extracorporeal shock-wave treatment of stones of the parotid gland. PATIENTS AND METHODS: 76 patients with symptomatic, sonographically proven, solitary stones of the parotid gland (36 females, 40 males; aged 2-80 years) were treated with extracorporeal piezoelectric shock-wave lithotripsy (ESWL) after failed conservative management (sialagogues, gland massage, duct bougie dilation). RESULTS: Parotid stones were no longer demonstrable after a mean follow-up time of 48 (6-71) months in 38 of the 76 patients; they were symptom-free and no new stones had formed. A residual, but symptom-free, stone was found in another 20 patients (26%) of whom 13 (17%) reported marked improvement after ESWL. No change from pretreatment symptoms occurred in five patients (7%) so that operative removal had to be performed. The success rate of the lithotripsy was independent of size and site of the stone. CONCLUSION: ESWL is the method of first choice in the treatment of parotid gland stones after unsuccessful conservative treatment and obviates operative gland removal in most cases.

Adolescent↗
PubMed1998

[Long-term experience with percutaneous endoscopic controlled gastrostomy (PEG) in ENT tumor patients].

Percutaneous endoscopically controlled gastrostomy (PEG) enables patients suffering from a tumor of the upper aerodigestive tract to receive direct gastric feedings. The procedure also avoids the social stigma of a nasal feeding tube. The results of 630 PEG procedures used in 555 patients suffering from various head and neck cancers are reported. The mean age of the patients was 58.0 years with a range from 11 to 92 years. The PEG procedure was carried out under local anesthesia in 60% of the cases and with general anesthesia in 40%. In 512 patients the initial PEG procedure was successful while 43 of the patients require a second PEG procedure after loss of the PEG. In 19 patients the PEG procedure was not successful because of tumor obstruction or it was not possible to perform endoscopy. Twenty-four patients were successfully treated in a second or third session. Although 97% (n = 563) of all 555 patients and 92% (n = 579) of all PEG procedures were successful. The mean duration of PEG use was 243 (range: 0-2271 days). In 66 patients (10.5%) complications occurred but severe complications developed in only 8 patients (1.3%). Operative interventions were necessary in two cases. No deaths resulted from the PEG. These findings show that the PEG technique is safe to do with only few complications when performed by a skilled team.

Adolescent↗
PubMed1998

[The diameter of the Stenon and Wharton ducts. Significance for diagnosis and therapy].

In assessing new minimally invasive diagnostic techniques (duct endoscopy) and therapy (lithotripsy) of salivary gland disease, it is of importance to know the true dimensions of the secretory ducts. Twenty-five ducts of the parotid gland and 20 ducts of the sub-mandibular gland were examined histologically at different points of their anatomic course and their in vivo diameters were evaluated using a previously determined formalin-induced shrinking factor. The mean diameter of Stensen's duct at four different points along its length ranged between 0.5 mm and 1.4 mm, depending on the site. A narrowing at the middle of the duct was striking. In all preparations examined, the minimum width of the secretory duct was located at the ostium. In Wharton's duct the narrowest duct diameter was also identified at the ostium. The mean values for the duct diameters ranged between 0.5 mm and 1.5 mm. For diagnostic and therapeutic purposes, endoscopes, balloon catheters and stone-extraction baskets should conform as much as possible to physiological duct widths. A diameter of 1.2 mm should be considered the upper limit for duct instruments. Our findings also suggest that in the case of salivary stone lithotripsy the best results will be achieved when the maximum size of a stone fragment does not exceed 1.2 mm.

Aged↗
PubMed1998

Cytotoxic and anti-proliferative effects of high-energy pulsed ultrasound (HEPUS) on human squamous cell carcinoma cells as compared to connective tissue fibroblasts.

The cytotoxic and anti-proliferative effects of high-energy pulsed ultrasound (HEPUS) on human squamous cell carcinoma cells cloned from the hypopharynx (FaDu) and benign connective tissue cells (fibroblasts) were investigated in vitro. Sonication was carried out using an experimental piezoelectric, self-focusing burst-signal transducer. To increase the induction of cavitation, the transducer used was specifically designed to produce multiple oscillations with a high negative pressure amplitude. In both cell lines tested, the application of 100, 800 and 2000 pulses resulted in a high reduction of vital cells. After 2000 pulses, 4.0 +/- 1.1% of the fibroblasts but only 2.0 +/- 0.4% of the FaDu cells survived HEPUS exposure. A postexposure inhibiting effect of HEPUS for 10 days on the proliferation of surviving cells was noted for the FaDu cells exposed to 2000 pulses, but not as much for the fibroblasts. These findings support the hypothesis that human squamous cell carcinoma cells of the hypopharynx might be more sensitive to HEPUS than fibroblasts and that total tumor cell ablation might be possible in vitro given a sufficient number of HEPUS pulses.

Carcinoma, Squamous Cell↗
PubMed1998

Diameters of the main excretory ducts of the adult human submandibular and parotid gland: a histologic study.

In assessing new minimally invasive diagnostic techniques (duct endoscopy) and therapy (lithotripsy), it is of importance to know the true dimensions of the excretory ducts. Twenty-five ducts of the parotid gland and 20 ducts of the submandibular gland were examined histologically at different points of their anatomic course, and their in vivo diameters were evaluated with the use of a previously determined formalin-induced shrinking-factor. The mean diameter of Stensen's duct at four different points along its length ranged between 1.4 mm and 0.5 mm, with a maximum of 2.3 mm and a minimum of 0.1 mm, depending on the site. A narrowing at the middle of the duct was striking. In all preparations examined, the minimum width of the excretory duct was located at the ostium. In Wharton's duct the narrowest duct diameter was also identified at the ostium. The mean values for the duct diameters ranged between 1.5 mm and 0.5 mm. The largest duct diameter reached 2.2 mm; the smallest one, 0.2 mm. For diagnostic and therapeutic purposes, endoscopes, balloon catheters, and stone-extraction-baskets probably should, despite the extensibility of the duct, conform as much as possible to the physiologic duct widths. A diameter of 1.2 mm should be aimed at as an upper limit for these instruments. Our findings also suggest that, in the case of salivary stone lithotripsy, the best results will be achieved when the maximum size of stone fragments does not exceed 1.2 mm.

Adult↗
PubMed1998

[Treatment of deep neck infections].

BACKGROUND: The incidence of deep neck space infections has been significantly reduced by modern antibiotic therapy. These infections are relatively rare and yet the life-threatening complications merit special consideration by head and neck surgeons. PATIENTS: Seven cases of deep neck space infections as a consequence of purulent pharyngitis (3), peritonsillar abscess (2), retropharyngeal (1), and odontogenic (1) abscess are presented. Despite antibiotic therapy according to antibiogram all patients showed an increase in complaints with persisting febrile temperatures and rising inflammation parameters. Surgical intervention became necessary. In two cases the infection spread into the mediastinum. RESULTS: All patients were completely cured by means of early surgical intervention including extensive drainage of the primary focus, deep neck spaces and mediastinum, accompanied by intravenous antibiotic therapy. Tracheotomy was performed on one patient with increasing dyspnea. All patients had an uneventful recovery without major postoperative complications. CONCLUSIONS: The clinical course of the disease must be observed particularly closely even after starting antibiotic therapy and identification of the infectious focus. Antibiotic therapy may in some cases cover clinical symptoms. However, in the presence of abscess formation or necrotizing infections, antibiotics can prove to be ineffective. The optimum time for surgery is difficult to determine. Complete drainage of the neck spaces down to the mediastinum is a safe procedure to save the patients' life. This shortens the duration of the disease and prevents complications. The most common problems in the management of deep neck space infections are discussed.

Abscess↗
PubMed1998

Extracorporeal shock wave lithotripsy of parotid stones. Results of a prospective clinical trial.

The extracorporeal shock wave treatment of parotid stones is a rather new therapy. Its usefulness was determined in a prospective study. Seventy-six patients (36 female, 40 male, 2 to 80 years of age) with symptomatic, sonographically detectable solitary sialoliths of the parotid gland were treated with an extracorporeal piezoelectric shock wave therapy after unsuccessful conservative therapy (sialagogues, gland massage, bougienage of the secretory duct). At most, 3 treatments per patient were performed. Altogether, 38 of the 76 patients (50%) were free of stones and no longer suffered from complaints after completion of shock wave treatment and a mean follow-up period of 48 months (range 6 to 71 months). During the follow-up period, in no case could renewed stone formation be observed. Residual stone fragments were detectable in 20 patients (26%), but did not cause further symptoms. Thirteen patients (17%) with residual stone fragments stated a significant improvement of their complaints after therapy. Five patients (7%) did not observe any changes of their pretherapeutic complaints and underwent parotidectomy. The therapeutic success was not influenced by stone size or by stone localization within the gland. During the follow-up period, no side effects of the therapy were identified. With stones of the parotid gland, extracorporeal shock wave lithotripsy is -- after one has used conservative therapies (sialagogues, gland massage) -- the treatment of choice, avoiding in the majority of cases a parotidectomy with its operative risks (paresis of the facial nerve, Frey's syndrome).

Adolescent↗
PubMed1996

In vitro effects of high-energy pulsed ultrasound on human squamous cell carcinoma cells.

Human squamous cell carcinoma cells cloned from the hypopharynx (FaDu) and oral cavity (SCC-4) were exposed to high-energy pulsed ultrasound (HEPUS) in vitro to evaluate the effects of various physical parameters on cell viability. Such included the number of pulses, voltage applied, pulse repetition rate and cell density. The experimental piezoelectric ultrasound transducer used in the experiments generated pulses with a high negative pressure amplitude. By varying the repetition frequency from 0.6 to 8 Hz, cell viability was found to be least when pulse repetition was approximately 1 Hz. An increase in transducer voltage resulted in a linear decrease in cell viability. The cell survival rate dropped exponentially as a function of the number of pulses applied, reaching 4.2% after 2000 pulses. The cell survival rate exhibited no significant dependence on cell density when cells ranged from 1 to 3.5 x 10(6) cells ml-1. Data obtained with trypan blue dye exclusion were confirmed by measurements of intracellular lactate dehydrogenase released into an extracellular fluid supernatant. By applying HEPUS to tumor cells, almost complete destruction of the cells could be achieved in vitro. The degree of cell destruction achieved depended significantly on the number of pulses administered, the pulse repetition rate and the transducer voltage applied.

Carcinoma, Squamous Cell↗
PubMed1996

[Color Doppler ultrasound studies of benign and malignant lymph nodes].

Color-coded duplex sonography is being increasingly used in the head and neck as another method for diagnosis of such disorders as stenosis of arteries or veins or hemangiomas. A possible additional advantage of testing is the ability to differentiate benign from malignant tumors. Since the underlying cause of a suspicious lesion is most important for treatment strategies, we investigated histologically-proven benign and malignant cervical lymph nodes for determining the value of color-coded duplex sonography. In the present study, 135 patients (45 women and 90 men; ages 30-63 years) with palpable cervical lymph nodes were examined with both ultrasound and color-coded duplex sonography. Afterwards, lymph nodes were removed by open biopsies or neck dissections. The histological results were then compared to perfusion velocities and pulsation indices from the color-coded duplex sonography. However, no significant differences were found between the benign and malignant nodes. When comparing perfusion and color, each group was seen to be non-homogeneous and no typical distribution of vascularization was demonstrable. Findings showed that color-coded duplex sonography is currently not an accurate indicator of lymph node pathology.

Adult↗
PubMed1996

[Current status of minimally invasive treatment methods in sialolithiasis].

Newly available minimally invasive methods have changed established treatment of human sialolithiasis during the past several years. After basic in vitro and in vivo investigations, two systems of shockwave treatment proved to be useful for clinical application: extracorporeal shockwave lithotripsy (piezoelectric system) and intracorporeal laser lithotripsy (using a rhodamine-6G dye laser). Following our clinical experiences with these methods a differential scheme for managing sialolithiasis is recommended depending on localization of the calculi and their maximal diameters. Submandibular stones are best treated by extra-corporeal lithotripsy if the stone is located in intraglandular parts or in the gland hilum. Stones of the hilum can also be treated by laser lithotripsy. In the distal parts and near the duct orifice, papillotomy and stone extraction should be tried independent of the stone size. If the stone is located in the intraglandular parts of the duct system or in the hilum and its diameter is over 12 mm, submandibulectomy is necessary. Calculi of the parotid gland should only be treated by extracorporeal lithotripsy, regardless of size and location.

Endoscopes↗
PubMed1995

[Pneumatic intracorporeal lithotripsy of salivary calculi. In vitro and animal experiment studies].

BACKGROUND: The effort to use minimally invasive strategies in the treatment of human sialolithiasis in principle seems to allow the clinical application of pneumatic lithotripsy because of the small diameters of the probes involved. While this kind of therapy is already used successfully in urology, we investigated the method during in vitro and animal experiments. MATERIALS AND METHODS: The treatment of stones and tissue utilized the pneumatic lithotripter "Lithoclast". This system works with ballistic energy and is similar to a biologic "pneumatic hammer". Thirty salivary calculi were treated with pneumatic lithotripsy. Four submandibular salivary glands and their ducts were removed intraoperatively and were exposed to the pneumatic probes. Moreover, in two cases a salivary concretion was also implanted prior to pneumatic lithotripsy. In two rabbits the ducts of the parotid glands were ligated for 2 weeks. On the basis of the in vitro experiments, concretions were placed in two of the four salivary ducts. Following this, the pneumatic probes were inserted along the ducts and lithotripsy was completed. RESULTS: All of the 30 salivary calculi were reduced to sizes smaller than 1.5 mm in diameter. No macroscopic or microscopic damage was detectable while the probe was in a duct. However, in both cases with implanted calculi retropulsion of fragments occurred consequent perforation of the ducts. After application of ballistic pulses along the duct, small periductal hematoma without any perforation were detected macroscopically. Microscopically, only small bleeding was observed along the submucosa and partial loss of epithelium was found. In contrast, the pulse application to the implanted concretions lead to destruction of the calculi with perforation of the ducts as well as hemorrhage in the surrounding tissue. CONCLUSIONS: The method of pneumatic lithotripsy used in the present study resulted in sufficient destruction of salivary calculi. In vitro and in vivo lithotripsy of duct implanted calculi led to perforation of the salivary duct in all cases. Because of these results, the clinical use of this technique to treat human sialolithiasis appears to be not justified.

Animals↗