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Biomedical subjects

C A van Hasselt

Publications and source records attributed to C A van Hasselt.

At least 19 recordsLinked to original sources
PubMed2000

Foley catheter action in the nasopharynx: a cadaveric study.

OBJECTIVES: To determine the action of the Foley catheter in the posterior nasal cavity in relation to balloon volume, and to deduce its implications in the treatment of posterior epistaxis. DESIGN: Human cadaveric study. MATERIALS: Twenty nasal fossae of 10 adult cadavers. INTERVENTIONS: A Foley catheter (size 14) was inserted into the nasopharynx via each nostril. The catheter balloon was inflated to its recommended maximum volume with 15 mL of water. Firm traction was applied to the catheter. Colored liquid was instilled into the ipsilateral aspect of the nasal cavity, and liquid leakage into the contralateral side was monitored using a nasoendoscope. The balloon was reduced in volume by 1-mL steps, and the same fluid infusion and documentation procedures were performed for each reduced volume until the balloon slipped out of the nose. The procedure was repeated in the opposite nostril. MAIN OUTCOME MEASURES: Successful choanal sealing and anterior balloon shift into the nasal fossa in relation to the balloon size. RESULTS: The Foley catheter balloon sealed the choana without any leakage of infused liquid into the contralateral side at appropriate inflation volumes in 17 (85%) of 20 nasal fossae. Complete sealing between volumes of 12 and 15 mL was achieved in 13 fossae (65%), between 11 and 15 mL in 10 nasal fossae (50%), and between 5 and 15 mL in 3 nasal fossae (15%). Failure to seal at any volume occurred in 3 nasal fossae (15%). Bimodal seal (ie, complete seal at high [15 mL] and low volumes [4-7 mL], but leakage in intermediate volumes) occurred in 3 nasal fossae (15%). The balloon remained in the nasopharynx under traction and did not slip past the choanal rim to encroach on the middle and inferior turbinates until the balloon volume was reduced to between 4 and 7 mL. The balloon slid out of the nose at a volume of 5 mL or less. The inflation volumes ranging from 8 to 12 mL were statistically more effective in sealing the choana than lower volumes (4-7 mL) (P<.002, chi(2) test). CONCLUSIONS: At different inflation volumes, the Foley catheter balloon acts primarily (1) as a platform for an anterior gauze pack (at 4-15 mL); (2) as an effective seal of the choana (at 8-15 mL usually and at 4-7 mL occasionally); and (3) as a compressor of the region behind the middle and inferior turbinates (at 4-7 mL), provided that the balloon under traction does not slip out of the nose.

Adult↗
PubMed2000

Dysphagia in treated nasopharyngeal cancer.

OBJECTIVES: To investigate the prevalence of long-term dysphagia in patients treated for nasopharyngeal carcinoma (NPC) by radiotherapy. Study Design Questionnaire-based assessment, clinical examination, and videofluoroscopic assessment of 50 patients, ages 26 to 75 years (average, 49 years), treated for NPC 12 to 119 months (average, 56 months) previously with no evidence of disease recurrence. METHODS: Administered questionnaire assessment of patients eating and swallowing. Clinical examination by a single experienced clinician. Videofluoroscopy was used to record swallowing of solid, paste, and liquid bolus. Pharyngeal transit time (PTT) was recorded, and the video recordings were assessed by two experienced observers for abnormalities. RESULTS: Fifty patients completed the questionnaire and were examined. Seventy-six percent reported dysphagia, 97% had xerostomia, and 78% had no gag reflex. Forty-nine patients underwent videofluoroscopy. Abnormal pharyngeal contraction was observed on videofluoroscopy in 93% of the subjects. Silent aspiration was observed in 22% of the patients. PTT was prolonged from a normal of 1 second to 1.9 seconds for solid, 1.7 seconds for paste, and 1.3 seconds for liquid consistencies. CONCLUSIONS: Subjective and objective swallowing abnormalities are common after radiotherapy for NPC. The implications of this finding and possible causes are discussed.

Adult↗
PubMed2000

Morphometric analysis of argyrophilic nucleolar organizer regions (AgNORs) in nasopharyngeal carcinoma.

BACKGROUND: Nucleolar organizer regions (NORs), which are loops of DNA containing ribosomal RNA genes, have been shown to correlate with cell proliferation and malignant transformation. Conventional eyeball measurement of silver staining NORs (AgNORs) is time-consuming and subject to error. The diagnostic value of AgNOR area in nasopharyngeal carcinoma (NPC) by computer-assisted morphometric analysis is evaluated. METHODS: Silver-staining of NORs was applied to 23 paraffin sections of NPC containing both normal squamous epithelial and malignant cells. Various parameters of the AgNORs of these two cell types were analyzed by a computer-assisted image analysis system and then compared. RESULTS: The mean AgNOR area, AgNOR/nuclear area ratio, and AgNOR area/count ratio of malignant tumors were statistically significantly higher than those for the normal epithelium. There was no significant difference in the AgNOR counts between the two cell types. CONCLUSIONS: Computer-assisted morphometric analysis of AgNOR is an objective and reliable assessment method applicable to paraffin sections of NPC. The AgNOR area and its derivatives may aid in the diagnosis of NPC.

Adult↗
PubMed2000

Fish bone inhalation in infancy.

Inhalation of sharp bones by infants is an uncommon but hazardous occurrence. management relies not only on a high index of clinical suspicion and timely treatment but also demands expertise in therapeutic bronchoscopy. The potential complications and the management of this condition are reviewed.

Animals↗
PubMed2000

Cochlear deafness in a Chinese family with Fechtner's syndrome.

OBJECTIVE: To identify the nature of the hearing impairment in the members of a Chinese family with Fechtner's syndrome. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: A Chinese family with a variant of Alport's syndrome: high-tone sensorineural hearing loss, proteinuria, macrothrombocytopenia, and ocular disease. INTERVENTIONS: The diagnosis of Fechtner's syndrome was confirmed by the characteristic ultrastructure of the Döhle-like inclusion bodies in the neutrophils of the mother and her three children. Pure-tone audiometry, evoked response audiometry (ERA), and distortion product otoacoustic emissions (DPOAE) were performed in two subjects to investigate the hearing impairment. MAIN OUTCOME MEASURE: The parameters of the ERA and DPOAEs were correlated. RESULTS: In both subjects, the ERA was within normal limits, and there were no measurable DPOAEs in frequencies >2 kHz. CONCLUSION: The hearing loss in Fechtner's syndrome is cochlear rather than neural.

Adult↗
PubMed2000

Endoscopic terminal dacryocystorhinostomy.

OBJECTIVE: Traditional endoscopic dacryocystorhinostomy (DCR) involves creation of a lacrimal sac side hole that may close down in the presence of a partially patent lower lacrimal drainage system. Endoscopic terminal DCR is a modified DCR procedure designed to prevent this problem. METHODS: From September 1996 to June 1999, 16 patients (17 sides) had endoscopic terminal DCR that involved resection of the lacrimal sac-duct junction to achieve total separation of the lacrimal sac from the nasolarcrimal duct and creation of a terminal DCR opening. RESULTS: Ten of the 17 DCRs were primary and 7 were revisions. The follow-up ranged from 3 to 36 months. There were two failures. One failure was due to canalicular obstruction and the other was due to prolapse of orbital fat hindering proper fashioning of the mucosal flap. The overall success rate was 88%. CONCLUSIONS: Instead of creating a side hole in the lacrimal sac as proposed by most endoscopic DCR studies, we advocate total diversion of tear flow by performing a terminal DCR opening that would further improve the success rate of endoscopic DCR, particularly in cases of idiopathic and partial obstruction.

Dacryocystorhinostomy↗
PubMed2000

New guidelines for endoscopic localization of the anterior ethmoidal artery: a cadaveric study.

OBJECTIVES: To determine objective data to improve the methods of identification of the anterior ethmoidal artery during endoscopic dissection. STUDY DESIGN: Cadaveric dissection of adult human heads. METHODS: A 0 degrees, 4-mm rigid endoscope was used to guide uncinectomy and frontoethmoidectomy. The location of the anterior ethmoidal artery was first determined visually and then confirmed by passing a needle through the anterior ethmoidal foramen from the orbit into the nose in all cases. The distances were endoscopically measured using a simple ruler between two nasal landmarks and the anterior ethmoidal artery. RESULTS: Fifty-six nasal fossae in 28 cadavers were dissected endoscopically. The median distance between the artery and the "axilla" formed by the anterior attachment of the middle turbinate to the lateral nasal wall was 20 mm (range, 17-25 mm), irrespective of the side. The measurement differed by less than 2 mm between the sides in the same individual. The median distance between the artery and the "axilla" formed by the medial and lateral crura of the lower lateral cartilage (superomedial edge of the nostril) was 62 mm (range, 55-75 mm) for both sides. The artery was found to be in direct alignment with the two "axillae" formed by the middle turbinate and the nostril edge. CONCLUSIONS: The distance between the ethmoidal artery and the axilla of the middle turbinate showed the least intraindividual and interindividual variations. The tip of the endoscope (or the ruler) points directly at the anterior ethmoidal artery in the fovea ethmoidalis when its edge is aligned with the two nasal landmarks. These simple guidelines can aid the identification of the artery in endoscopic frontoethmoidectomy.

Adult↗
PubMed2000

Efficacy of ondansetron for prevention of postoperative nausea and vomiting after outpatient ear surgery under local anesthesia.

OBJECTIVE: To assess the efficacy and safety of intravenous ondansetron (4 mg) for the prevention of nausea and vomiting after middle ear surgery under local anesthesia. SETTING: The study was conducted by Division of Otorhinolaryngology in Prince of Wales Hospital, which is a tertiary referral center and teaching hospital for The Chinese University of Hong Kong. STUDY DESIGN: A double-blind randomized controlled trial. PATIENTS: Fifty-eight Chinese patients undergoing tympanoplasty under local anesthesia from July 1995 to June 1997 were recruited. The mean age of patients was 42.8 years (range 18-71 years). INTERVENTION: Patients were randomly allocated to receive a single dose of intravenous ondansetron (4 mg) (n = 29) or placebo (n = 29) immediately before surgery. MAIN OUTCOME MEASURES: Patients were assessed for severity and frequency of postoperative nausea and vomiting at the 1st, 2nd, 4th, 8th, and 24th hours after middle ear surgery. RESULTS: Female patients showed a higher prevalence of postoperative nausea and vomiting. Twenty-eight percent of the patients experienced postoperative nausea, of whom 14% also experienced vomiting. Although the ondansetron group demonstrated a lower prevalence of postoperative nausea and vomiting (PONV) (24% nausea and 10% vomiting) than the placebo group (31% nausea and 17% vomiting), significant reduction in postoperative vomiting only occurred in the first postoperative hour (p = 0.038). No complications or adverse side effects were found to be associated with the use of ondansetron. CONCLUSIONS: Single-dose ondansetron (4 mg) given intravenously preoperatively significantly reduces postoperative vomiting in patients after tympanoplasty under local anesthesia and causes no adverse effects.

Adolescent↗
PubMed2000

Screening for otitis media with effusion to measure its prevalence in Chinese children in Hong Kong.

In an attempt to gain a better understanding of the prevalence of otitis media with effusion (OME) in the Hong Kong community, and to compare the characteristics of the disease here with OME as it is described in the Western literature, we screened more than 6,000 6- and 7-year-old children with both clinical and audiologic examinations. The initial positive screening rate was 5.3%. Upon further evaluation, we determined that the overall prevalence of persistent OME was 2.2%. We found that the disease pattern and natural history of persistent OME in Hong Kong children are similar to those reported in the Western literature.

Acoustic Impedance Tests↗
PubMed2000

Giant benign sinonasal squamous papilloma: report of a case.

We treated a patient with a giant squamous papilloma in the nasal cavity and maxillary sinus that extended through a bony defect into the oral cavity. The mass was excised with a combined endoscopic, Caldwell-Luc, and transoral approach. Lesions of this type are rare, but when they do occur, the rate of recurrence is high. Therefore, long-term followup, including endoscopic examination, is important.

Adult↗
PubMed2000

Middle ear effusions after radiotherapy: correlation with pre-radiotherapy nasopharyngeal tumor patterns.

OBJECTIVE: The purpose of this study was to assess whether pretreatment tumor patterns of nasopharyngeal carcinoma (NPC) can predict the status of the middle ear after radiation treatment. MATERIALS AND METHODS: Pretreatment and follow-up magnetic resonance imaging (MRI) was performed in 32 patients (64 ears) who had radiation therapy for NPC. For the purpose of analysis, the ears were placed into their pre-radiation therapy tumor pattern groups and the presence of middle ear effusion (MEE) with regard to eustachian tube (ET) invasion or displacement was identified. RESULTS: MEEs were present in 31 (48.4%) ears after radiation therapy. All of the MEEs that resolved were in the preradiation therapy groups where tumor invasion of the eustachian tube was present irrespective of the amount of ET displacement. There was, however, no significant difference for resolved MEEs between ears with ET invasion or displacement (p = 0.32 and p = 0.71, respectively, Fisher's exact test). The MEEs occurred with significantly greater frequency in ears with minor ET displacement than in those with major ET displacement (p = 0.013, Fisher's exact test) as well as in previously normal ears compared with other groups (p = 0.008, Mann-Whitney U test). CONCLUSION: A pre-radiation therapy NPC tumor pattern was not found that clearly predicted the outcome of MEE after radiation treatment. The findings, however, suggest that approximately one third of MEEs in patients with invasion of ET or paratubal structures, irrespective of the amount of ET displacement, resolve after therapy. The MEEs that were present in ears with ET displacement and no invasion did not resolve despite reversal of the displacement after treatment, which suggests that ET position plays a less important role than invasion in the resolution of MEE. It is, however, difficult to be certain, because ears with invasion were invariably associated with ET displacement, and the contribution of radiation therapy to the development of MEE further complicates the issue.

Adult↗
PubMed1999

Percutaneous embolization to control intractable epistaxis in nasopharyngeal carcinoma.

BACKGROUND: Epistaxis in patients with nasopharyngeal carcinoma (NPC) who have received radiotherapy can be difficult to control by conventional methods. The use of angiography and embolization to control problematic epistaxis has been well documented in other situations, but its use in severe or recurrent epistaxis following irradiation for NPC has not been described. METHODS: We retrospectively reviewed case notes of all patients with NPC initially seen with epistaxis over a 4-year period. Those patients with refractory epistaxis which could not be controlled by conventional methods and required angiography and embolization were assessed. RESULTS: Eight patients who underwent angiography were identified. Five patients showed hypervascularization and three patients had pseudoaneurysms or an aneurysm of the internal carotid artery seen on the angiogram. All these patients were successfully embolized. There were no significant complications after the procedure. CONCLUSION: We conclude that embolization is a safe and effective method of controlling refractory epistaxis in patients irradiated for NPC.

Adult↗
PubMed1999

Retropharyngeal abscess. A rare presentation of nasopharyngeal carcinoma.

Early symptoms of nasopharyngeal carcinoma (NPC) can often be deceptive and confusing. Most patients with nasopharyngeal carcinoma present at an advanced stage with metastatic cervical nodes present at the time of diagnosis. A deep neck abscess as the presenting feature has not been reported. We report two cases of nasopharyngeal carcinoma which presented with retropharyngeal abscesses and persistent lymphadenopathy. These two patients illustrate that refractory lymphadenopathy, despite adequate treatment of the associated infection, should prompt a search for underlying disease. The relationship between nasopharyngeal carcinoma and retropharyngeal abscess is discussed.

Adult↗
PubMed1999

Diagnosis of peritonsillar infections: a prospective study of ultrasound, computerized tomography and clinical diagnosis.

Peritonsillar infections include cellulitis and abscess (quinsy). Clinical diagnosis is often supplemented by diagnostic drainage (aspiration or incision) in an effort to distinguish abscess from cellulitis. In a prospective study of 14 patients we have shown that clinical impression alone is unreliable (sensitivity 78 per cent, specificity 50 per cent). Computerized tomography (CT) (sensitivity 100 per cent, specificity 75 per cent) and intraoral ultrasound (sensitivity 89 per cent, specificity 100 per cent) are much more reliable. We propose that intraoral ultrasound could play a useful role in the clinical assessment of peritonsillar infections helping to improve accuracy in distinguishing abscesses from cellulitis.

Adolescent↗
PubMed1999

Nasal manifestation of extranodal Rosai-Dorfman disease--diagnosis and management.

Two cases of Rosai-Dorfman disease with polypoid nasal infiltration mimicking nasal tuberculosis and malignant lymphoma are reported. This rare benign disease was first described by Rosai and Dorfman in 1969 and is characterized by histiocytic proliferation. It is seldom considered in the differential diagnosis of granulomatous diseases due to its rarity and histological similarity to other diseases. Extranodal manifestations of this disease are uncommon. Although no specific treatment can guarantee a sustained remission of this disease, surgery for loco-regional lesions can result in long-term symptomatic control and restoration of function. Both patients underwent endoscopic resection of the nasal polypoid lesions and have subsequently been free of recurrence. Loco-regional infiltration of the nasal cavity by Rosai-Dorfman disease is effectively managed by endoscopic resection.

Adult↗
PubMed1999

Compartmentalized maxillary sinus mucocele.

A rare case of compartmentalized maxillary sinus mucocele 12 years after a Caldwell-Luc operation is reported. The two separate mucoceles were drained intranasally by endoscopic sinus surgery. The clinical features of this mucocele are presented and the incidence, presentation and theories on formation of post-operative mucoceles are reviewed.

Adult↗