Risk factors for postoperative delirium: An umbrella review of systematic reviews.

BACKGROUND: Postoperative delirium (POD) is associated with increased mortality, increased length of hospital stays and increased rates and severity of subsequent cognitive decline including dementia. A wide range of risk factors for POD have been suggested in the literature across multiple surgical specialities. However few are validated and no accurate prognostic models exist. We therefore aimed to map the existing evidence regarding risk factors for POD to help guide future research by undertaking an umbrella review of systematic reviews examining risk factors for POD in any context. MATERIALS AND METHODS: We systematically searched multiple medical databases for systematic reviews examining the risk factors for POD in adults undergoing any surgery. We then selected relevant reviews with minimal overlap in primary studies and extracted information about individual risk factors. RESULTS: Thirty-five relevant reviews were identified of which ten were in trauma and orthopaedic surgery patients (four exclusively examined hip fractures), five were in cardiac surgery patients, and four were in vascular surgery patients. Due to substantial overlap in reviews, eighteen reviews were analysed in detail finding the widely examined and consistent risk factors were increasing age, nursing home residency, pre-existing cognitive impairment, psychiatric disorders, cerebrovascular disease, end stage renal failure, low albumin, higher ASA score, and intra-operative blood transfusion. Many other risk factors were examined, but they were either not studied in multiple systematic reviews, or inconsistent either in results or in categorisation (which for many factors was heterogenous even within systematic reviews). There are also a large number of existing prognostic models, many of which remain unvalidated. CONCLUSION: Given the wealth of existing literature, future research should avoid simple risk factor evaluation except for novel candidates, validate existing prognostic models where possible, and instead focus on interventional research.

Guidelines for Clinical Target Volume Definition for Perineural Spread of Major Salivary Gland Cancers.

AIMS: Postoperative radiotherapy is the standard of care for resected major salivary cancers that are at risk of locoregional recurrence. Of the various histological subtypes, perineural invasion is most common in adenoidcystic carcinomas of the three major salivary glands - parotid, submandibular and sublingual. The clinical target volume (CTV) for these cases must include the relevant cranial nerve pathways at risk. A contouring atlas was devised for delineation of the CTV of the nerves supplying the major salivary glands. MATERIALS AND METHODS: Using standard anatomy texts and e-anatomy sources the nerves supplying the major salivary glands were identified. Subsequently the pathways of the nerves were drawn on an archived patient's planning computed tomography scan. RESULTS: The innervation of the major salivary glands has been identified and studied. Both bone and soft tissue CTVs have been delineated. A full set of images and CTVs of all the relevant transverse computed tomography slices has been archived, a number of which are printed in this article. CONCLUSIONS: Variation in CTV delineation is a recognised problem in a variety of anatomic sites. Guidelines and atlases can standardise practice and may improve the safety and efficacy of therapy. An atlas has been generated to guide clinicians in delineating the CTVs for perineural spread in major salivary gland cancers.

Multifocal Langerhans' cell histiocytosis: a case report.

OBJECTIVES: Langerhans' cell histiocytosis (LCH) is a rare disorder of unknown aetiology, characterised by the proliferation of histiocytic cells in various tissues and organs. The role of the otolaryngologist is important in the early and accurate evaluation, staging and diagnosis of LCH, as it may mimic more common otological disorders. METHOD: We report the case of a 2-year-old child presenting with LCH and review the literature concerning this rare disease. RESULTS: Presentation in our case was with a common aural polyp, refractory to medical treatment, which when biopsied, revealed LCH. Radiological evaluation showed multifocal disease. CONCLUSION: A sound knowledge of the disease process in vital to the otolaryngologist, thus enabling rapid diagnosis and early treatment for a commonly fatal condition.

Acute mastoiditis in children: presentation and long term consequences.

UNLABELLED: Acute mastoiditis, a destructive bacterial infection of the mastoid bone and air cell system, is relatively uncommon today but remains a potentially serious condition. There is a lack of information in the literature regarding the long term otological problems that children may face following an episode of this condition. OBJECTIVES: Our aim was to examine the presentation, complications and hospital course in this patient population, and to ascertain whether these patients had long term otological problems. METHODS: We retrospectively reviewed the medical records of all patients presenting with acute mastoiditis between January 1990 and December 2005. Patients' parents were contacted by telephone and questioned about further otological problems. RESULTS: Twenty-nine patients were included in the study, and 27 of these patients' parents were contactable to complete the telephone questionnaire. Sixty-nine per cent of children had no previous history of acute otitis media prior to presentation. Forty-five per cent of patients had received oral antibiotics prior to presentation. Sixty-two per cent of patients developed complications, i.e. a subperiosteal abscess or failure to respond to medical therapy, resulting in the need for surgical intervention (in the form of incision and drainage of periosteal abscess, cortical mastoidectomy, or grommet insertion). Mean follow up of patients was eight years and one month; five (17 per cent) patients had been followed up for less than one year. Two (7 per cent) patients developed a further episode of mastoiditis within six weeks of initial presentation, both of whom required cortical mastoidectomy. Three (10 per cent) patients had further problems with recurrent acute otitis media, requiring tympanostomy tube insertion. One patient required a modified radical mastoidectomy for cholesteatoma (15 years later). Twenty-two patients (91 per cent) had been followed up for longer than one year; these patients had subjectively normal hearing and were asymptomatic at the time of study. CONCLUSION: The majority of patients who had suffered an episode of acute mastoiditis had no adverse long term otological sequelae.

Tonsillectomy--cold dissection vs. hot dissection: a prospective study.

Throughout the years, investigators and surgeons have developed new techniques for tonsillectomy aiming to lessen the postoperative morbidity and complications of tonsillectomy. It is generally accepted that the ideal method should decrease operative time, blood loss, postoperative haemorrhage and morbidity. To compare the technique and post-operative morbidity of two different tonsillectomy methods: cold dissection and bipolar electrodissection. A prospective study including a total of 545 children (Age: 3-16 yrs) undergoing tonsillectomy at The Children's University Hospital in Dublin, Ireland, from January 2003 to December 2003. The incidence of primary, secondary haemorrhage and postoperative pain was compared between both techniques. The overall rate of haemorrhage was 3.6% (20 patients) this included primary haemorrhage in 0.3% (2 patients) and secondary haemorrhage in 3.3% (18 patents). Primary haemorrhage occurred only in the electrodissection technique. As regards to secondary haemorrhage it was higher in the electrodissection technique 2.3% (12 patients) compared to 1% (6 patients) of the cold dissection technique. Patients rated pain to be more severe in the electrodissection technique compared to the cold dissection technique. Cold dissection tonsillectomy technique is still considered to be a safe and effective method with less posoperative morbidity complications as evidenced from our study.

Bone anchored hearing aids: reality, failure and current status.

Bone Anchored Hearing Aids have both cosmetic and acoustic advantages over most conventional hearing aids and hence is a popular choice today. We report the first Irish group of patients who received a BAHA over a six year period of time and evaluated outcomes of these subjects using subjective assessment. The medical records of all patients who received a BAHA at the Mater and Children's University Hospital, Dublin, were reviewed. A questionnaire had been sent to the patients to obtain long-term subjective information. Twenty three patients were identified. The commonest indication for surgery was found to be the presence of a discharging mastoid cavity, followed by congenital ear malformations. Surgical procedures were carried out as a single stage in 16 patients. Questionnaires were sent to 19 patients; sixteen patients responded in total. BAHA has a beneficial outcome to the quality of life and has significantly reduced ear discharge. The one stage technique was found to have a lower complication rate.

The effect of prosthesis design on vibration of the reconstructed ossicular chain: a comparative finite element analysis of four prostheses.

HYPOTHESIS: It was hypothesized that the differences in the bioacoustic performance of ossicular replacement prosthesis designs, and insertion positions, could be quantified using finite element analysis. BACKGROUND: Many designs of prosthesis are available for middle ear surgery. The materials used, and the shape of the implants, differ widely. Advances in computer simulation technologies offer the possibility of replicating the in vivo behavior of the different prostheses. If this can be achieved, insight into the design attributes required for improved biofunctionality may be gained. METHODS: Micro-computed tomography and nuclear magnetic resonance imaging were used to obtain geometric information that was translated into a finite element model of the outer and middle ear. The forced frequency response across the hearing range of the normal middle ear was compared with the middle ear reconstructed with partial and total ossicular replacement prostheses. RESULTS: The amplitude of vibration of the footplate was more similar to that of the normal ear when a Kurz total ossicular replacement prosthesis was implanted than when a Xomed total ossicular replacement prosthesis was implanted. This may be attributed to the latter's titanium link. Partial ossicular replacement prostheses were stiffest and had lower umbo vibrations and higher stapedial footplate vibrations. In all cases but one, the vibration of the prostheses had resonances that caused the vibration of the stapes footplate to be noticeably different from normal. CONCLUSION: The authors confirmed the hypothesis that finite element modeling can be used to predict the differences in the response of ossicular replacement prostheses. This study shows that computer simulation can potentially be used to test or optimize the vibroacoustic characteristics of middle ear implants.

Cleft palate and otitis media with effusion: a review.

Otitis media with effusion is a common finding in children with cleft palate. However, although middle ear effusions have been reported to be almost universal among infants with cleft palate, less is known regarding the epidemiology, natural history, and outcome of middle ear disease among older children with cleft palate. Furthermore, considerable controversy surrounds the management of otitis media with effusion in these children: many authors have advocated a policy of early or scheduled ventilation tube insertion on account of the high incidence of hearing loss and speech difficulties; others have advocated a more conservative policy on account of the high incidence of complications from ventilation tubes and lack of evidence supporting a policy of early intervention. In the present paper, we review the epidemiology, aetiology, and natural history of middle ear disease in children with cleft palate. We also discuss the controversies involved in the management of these patients.

Sequelae of otitis media with effusion among children with cleft lip and/or cleft palate.

Otitis media with effusion (OME) is common among children with cleft palate, and may lead to such long-term consequences as hearing loss, tympanic membrane retraction, and chronic otitis media (COM). In total, 104 children with cleft lip and/or palate treated for OME at our institution were reviewed. Mean duration of follow-up was 6.9 years, and mean age at latest follow-up was 9.6 years. The incidence of COM was 19%, and the incidence of cholesteatoma was 1.9%. Ears showing such long-term sequelae of OME as hearing loss, tympanic membrane retraction, and chronic otitis media, were noted to have undergone a significantly greater number of ventilation tube insertions than ears not showing these sequalae. Our findings would suggest that a conservative approach to the management of OME in children with cleft palate is more likely to be beneficial in the long term.

Pseudoexfoliation and sensorineural hearing loss.

AIMS: There is increasing evidence that pseudoexfoliation (PXF) not only affects ocular anterior segment structures, but may also be a systemic disease. This study was undertaken to assess the relationship between PXF and sensorineural hearing loss. METHODS: Patients with PXF were identified from hospital records and underwent complete ocular examination. The sum of pure-tone hearing thresholds measured at 1, 2 and 3 kHz (HTL1,2,3) in each ear was compared with the ISO 7029 standard sex-matched, median age-associated hearing loss summed over the same frequencies (AAHL1,2,3). The proportion of ears with thresholds higher than the ISO 7029 median AAHL1,2,3 on the same side as eyes without PXF was compared with the proportion of ears ipsilateral to eyes with PXF but without glaucoma and similarly the proportion of ears on the same side as eyes with PXF and glaucoma. RESULTS: In total, 69 patients were studied, of whom 39 were male (56.5%). The mean age of the male patients was 75.8 years, while that of the female group was 75.1 years. All patients had PXF affecting at least one eye. Overall 101 ears (73.7%) had a higher HTL1,2,3 than the ISO 7029 median AAHL1,2,3 which included 56 ears of 78 in the male group (71.8%) and 45 ears of 59 in the female group (76.3%). There was no significant difference between the proportion of ears with HTL1,2,3 higher than the ISO 7029 median AAHL1,2,3 on the same side as eyes without PXF, with PXF but not glaucoma and with PXF and glaucoma, in either the male or female groups. CONCLUSIONS: A large proportion of patients with PXF have sensorineural hearing loss in comparison to age-matched controls, regardless of whether or not there is associated glaucoma. This finding supports the theory that PXF may be a systemic condition.

Pulmonary embolism following tonsillectomy.

Acute post-operative pulmonary embolism is a serious potentially life-threatening complication which is not anticipated in young patients undergoing non-major surgery. We report a case in which a 32-year-old previously healthy woman developed a major pulmonary embolism following tonsillectomy. Subsequent investigations revealed the presence of an occult malignancy. This case highlights the role of paraneoplastic hypercoagulable states in the aetiology of venous thromboembolism and the importance of thromboprophylaxis in the presence of confirmed or suspected malignancy. To our knowledge no case of major pulmonary embolism occurring after tonsillectomy has been previously reported.

The effect of ventilation tubes on stresses and vibration motion in the tympanic membrane: a finite element analysis.

Finite element analysis is used to determine the mechanical behaviour of structures. The deformation of a structure caused by a force can be calculated, and the stresses and strains within the component can be found. In brief, a geometric representation-a 'drawing'-of the structure is loaded into a computer, and a component is divided into 'elements' which usually have the shape of 'bricks'. A common analogy is a 'lego' brick assembly. The deformation of an element can be determined using engineering formulae, and the deformation of the whole structure can be determined when the elements are re-asssembled. There have been very few analyses of the biomechanical behaviour of ventilation tubes, or grommets, even though clinical studies have indicated that tube design and material determines extrusion rates and may influence tympanosclerosis. This paper reports a comprehensive biomechanical analysis of the effect of a grommet on the tympanic membrane. Analytical and computer simulation techniques (finite element analysis) are used to determine the changes in the vibratory motion and stresses in the membrane when a Reuter-Bobbin ventilation tube is inserted. It is found that the presence of a ventilation tube significantly affects the motion of the membrane in the neighbourhood of the implant. When the effect of implant material is investigated, it is found that the amplitude of motion of a heavier metal implant is less than a lighter polymeric implant. If it is true that higher motion predisposes towards early extrusion, then the lighter implant (polyethylene) is predicted to have a higher extrusion rate. Regarding the maximum stresses in the tympanic membrane, they form a crescent-shaped region in the anterior and posterior quadrants in the regions where tympoansclerosis is observed. The magnitude and pattern of the stress is predicted not to depend significantly on the presence of the tube. This suggests that tympanosclerosis is not determined by the implant per se and therefore that no tube design feature can be expected to prevent it.

Vibro-acoustic modelling of the outer and middle ear using the finite-element method.

In this study, a computer-based method called finite-element analysis is used to predict the forced-frequency response of the ear, with and without an ossicular replacement prosthesis (PORP 0362, Xomed Surgical Products). The method allows visualisation of the dynamical behaviour of the tympanic membrane (TM) and of the ossicles. The finite-element model is fully three-dimensional and includes both ligaments and muscles, and accounts for damping caused by the TM, ligaments, incudostapedial joint and the fluids of the inner ear. For validation, comparison is made with experimental measurements of umbo displacement taken from the literature. The translation and rotation (both anterior-posterior and inferior-superior) of the stapedial footplate are investigated. It is predicted that the translatory motion of the footplate decreases with increasing frequency, except when the frequency of the acoustic signal matches the natural frequencies of the ossicular chain or outer ear canal. The tilting motion of the stapedial footplate is also predicted to depend on frequency of excitation. The presence of a prosthesis changes the dynamical response considerably by shifting the natural frequencies of the ossicular chain. Ratios of stapes motion with and without the prostheses are plotted as a function of frequency allowing this effect to be clearly observed.

Modelling medical devices: the application of bioengineering in surgery.

Medical device technology has an increasingly important role in surgical procedures. In this article, five case studies of bioengineering in surgery are described as follows: computer-aided design of vascular grafts; middle-ear prostheses; hip prosthesis stems for optimal cement pressurisation; prototype development of a device for measurement of abdominal sounds for monitoring digestive tract activity and a hand-access device for laparoscopic surgery. In each case, new bioengineering design methodologies are demonstrated. The general principles underlying the application of bioengineering in surgery are discussed.

Cutaneous presentation of nasal lymphoma: a report of two cases.

Two patients with nasal lymphoma were seen with cutaneous lesions. Multiple biopsy specimens, immunohistochemical techniques, and gene rearrangement studies were required to establish the diagnosis.

The widened retrolabyrinthe approach: a new concept in acoustic neuroma surgery.

For many years, the retrolabyrinthine approach has been limited to functional surgery of the cerebellopontine angle (CPA). As a result of the increased surgical exposure, particularly the opening of the internal auditory meatus (IAM), the widened retrolabyrinthine technique permits tumor excision from both the CPA and the IAM, regardless of the histological nature of the tumor. The authors have treated 60 acoustic neuromas of varying sizes via this approach (6% intrameatal tumors; 30% > 25 mm in diameter). The postoperative mortality rate was 0%. The risk of fistula formation was 3.3%, and 3.3% of the patients suffered from postoperative meningitis. The results for facial nerve function were equivalent to those obtained previously via a widened translabyrinthine approach and those in a series treated via a suboccipital approach (80% with Grades I and II, 15% with Grade III, and 5% with Grades V and VI). One patient (1.7%) required a secondary hypoglossal-facial nerve anastomosis and had attained a Grade IV result 6 months later. Postoperatively 21.7% of these patients maintained socially useful hearing and 20% had mediocre hearing. Socially useful hearing was preserved in 50% of a subgroup of 20 patients who had both good preoperative hearing and a tumor that involved less than half of the IAM regardless of its volume. Additionally, 15% had mediocre hearing that could be improved with hearing aids. Because of its efficacy in preserving hearing, the authors favor the retrolabyrinthine over the occipital approach, with the latter being considered less subtle and more aggressive.

Mode shapes of a damaged and repaired tympanic membrane as analysed by the finite element method.

This work makes use of recent finite element discretization of the human tympanic membrane where the known anisotropy of the tympanic membrane is implemented by a series of thin beam elements superimposed on thin shell membrane elements. These thin beam elements were introduced in order to simulate the fibre structure of the tympanic membrane. The onset of tympanosclerosis has been modelled as a gradual increase in tympanic membrane density and modulus in the affected area. This increased density results in a fall of 55% of the first natural frequency for only a 16% area of drum sclerosis. Additionally the amplitude response is significantly reduced. Repair of the membrane was simulated by removal of the fibre system from the affected area. Under these circumstances the natural frequencies virtually return to the healthy state but the mode shapes of vibration do not. The repair to the membrane, although not significantly altering frequency values, has resulted in a disruption to the normal mode shape patterns with consequences in the movements conveyed to the stapes and cochlear fluids.

A dynamic and harmonic damped finite element analysis model of stapedotomy.

This study was undertaken in an attempt to better understand the mechanics of sound transmission at the footplate following stapedotomy. The insertion of a Teflon (polytetrafluoroethylene) stapes prosthesis introduces new constraints within the reconstructed ossicular chain which have an effect on the normal vibration patterns of the tympanic membrane. In a finite element model of the ear, constraints have been reproduced as a series of spring constants in the incus/prosthesis/footplate interfaces incorporating damping to simulate the impedance of the inner ear. At zero damping, the frequency response at the pseudo stapes footplate exhibit several maxima and minima between 800 Hz and 2.5 Hz. At higher damping values, these maxima and minima become smoothened out with two or three naturals occurring over the same frequency range. Severe ankylosis of a diseased footplate is reproduced by over-damped conditions. The umbo, incus and stapes footplate vibrate in phase with similar frequencies at light damping levels. The movement of the prosthesis at the pseudo-footplate can be large in the out of plane axis of the ossicular chain, unless sufficient support is provided at the reconstructed footplate. Clinically, this would suggest the vein graft interposed between the piston and stapedotomy hole should endow resistance and elasticity to the system.

Ultrasonography in the evaluation of neck abscesses in children.

A prospective study evaluating the benefits of preoperative ultrasonography of paediatric neck abscesses is presented. Twenty-three consecutive children who presented with suspected neck abscesses to the Accident and Emergency Department at the Temple Street Children's Hospital between 1990 and 1992 have been evaluated prospectively. On admission, ultrasonography showed a collection of pus in 11 children and these underwent incision and drainage. The other 12 had intravenous antibiotics. Six of these remained pyrexial and had a repeat ultrasound after 72 h revealing pus which was drained. The remaining were managed successfully with medical treatment. In this study there were no negative surgical interventions and we recommend ultrasonography for preoperative evaluation of children with suspected inflammatory neck abscesses.

Clearance of recalcitrant psoriasis after tonsillectomy.

Infection is a well-recognized triggering factor for both guttate and chronic plaque psoriasis. We investigated prospectively 13 patients with recalcitrant psoriasis exacerbated by recurrent tonsillitis, who underwent tonsillectomy between 1990 and 1993. There were 12 female patients and one male, with a mean age of 17 yr (range 6-28). Six patients had guttate psoriasis resistant to standard treatments and seven patients had chronic plaque psoriasis exacerbated by tonsillitis that was severe enough to warrant at least one admission to hospital. Patients were followed by chart review and postal questionnaire. Psoriasis was cleared completely after tonsillectomy in five out of the six patients (83%) with guttate psoriasis and was improved in one patient. Two out of seven patients with plaque psoriasis (29%) were cleared, two (29%) were improved and three (42%) were unchanged. We conclude that tonsillectomy may be a successful treatment modality in selected patients with recalcitrant guttate or chronic plaque psoriasis.