Implications of screening for abdominal aortic aneurysms on surgical workload.

BACKGROUND: The Multicentre Aneurysm Screening Study (MASS) provided strong evidence for both the clinical benefit and the cost-effectiveness of a screening programme for abdominal aortic aneurysms (AAAs) in men. If a national screening programme for AAA were adopted in the UK, it would be expected to increase the elective and decrease the emergency surgical workload. METHODS: The MASS trial randomized 67,800 men aged 65-74 years to be invited to attend for ultrasonographic screening for AAA or to a control group that received no invitation. Predictions of elective and emergency surgical workload were made for a 20-year interval after the introduction of a screening programme for 65-year-old men, based on surgical rates observed in the MASS trial and national mortality statistics. RESULTS: For a district general hospital serving a population of 400,000, there was an estimated reduction from nine emergency operations per year before introduction of the screening programme to three emergency operations annually in men aged 65 years and over by the end of the 20-year interval, and an increase from 24 to 43 AAA operations overall. The corresponding estimated annual costs for all AAA surgery increased by 47 per cent, from pound 209,000 to pound 308,000. These results were not affected by changes in the underlying assumptions. CONCLUSION: The results support the expectation of very few emergency operations, and principally elective operations, being performed following the introduction of a screening programme. For a typical district general hospital, a screening programme would be expected to lead to two additional elective AAA operations per month, and to save 11 AAA-related deaths per year.

Comparison of P-POSSUM risk-adjusted mortality rates after surgery between patients in the USA and the UK.

BACKGROUND: The Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM) criteria have been used to assess surgical risk in patients in the UK. The aim was to determine how applicable these criteria are to patients undergoing surgery in the USA. METHODS: Two cohorts of patients undergoing major non-cardiac surgery were followed prospectively in the USA (n = 1056) and the UK (n = 1539). Each patient was assigned a risk score for preoperative physiological status and operative severity using the established POSSUM criteria. Death in hospital was the primary outcome measure. For each patient a predicted risk of death was calculated from Portsmouth POSSUM (P-POSSUM) methodology using an established equation. The relationships between predicted and observed mortality rates in each cohort were investigated by means of multivariate logistic regression. RESULTS: Within each cohort, an increase in risk estimated by P-POSSUM predicted an increase in observed mortality rate (P < 0.001). For any given risk level, however, mortality rates were significantly higher in the UK cohort than in the US cohort (odds ratio 4.50 (95 per cent confidence interval 2.81 to 7.19); Z = 6.25, P < 0.001). CONCLUSION: An increase in predicted risk, based on the P-POSSUM methodology, was associated with a higher mortality rate in patients from both countries. However, risk-adjusted mortality rates following major surgery were four times higher in the UK cohort. These marked differences warrant validation in a larger number of centres.

Towards a national clinical minimum data set for general surgery.

BACKGROUND: Measurement and comparison of surgical performance is accepted as necessary and inevitable. Risk-stratified (case-mix adjusted) models of clinical outcomes form a metric with which to assess performance, but require accurate data. Collecting such data in the clinical environment is time consuming and difficult. This study aimed to construct effective models, for operative and non-operative admissions, from routine clinical data residing in hospital computers, so minimizing data collection and quality problems, and facilitating national implementation. METHODS: Data for 3181 non-operative emergency, 5039 elective and 3043 emergency operative admissions for the 2 years beginning 1 August 1997 were used to generate logistic regression equations for risk of death, which were applied prospectively to the following 3 years' data. RESULTS: The models use urea, haemoglobin, white blood cell count, sodium, potassium, age on admission, sex, British United Provident Association (BUPA) Operative Severity Score (for operative admissions) and, implicitly, mode of admission and mortality at discharge. All three models successfully stratified risk into five or more bands. CONCLUSION: Effective models of mortality, applicable to all general surgical admissions, can be constructed from existing routine clinical data, largely obtained from a single venesection. The data set is a candidate national clinical minimum data set.

Epithelial ingrowth: causes, prevention, and treatment in 5 cases.

PURPOSE: To examine the clinical course, treatment, and outcome in 5 cases of epithelial ingrowth following laser in situ keratomileusis (LASIK). SETTING: The Eye Institute, Sydney, Australia. METHODS: Five patients with adequate follow-up were selected. Each patient had developed epithelial ingrowth as a consequence of LASIK, and each represented a different clinical course in terms of severity, time, and treatment of the epithelial ingrowth. RESULTS: Treatment ranged from observation, lifting and manual removal, phototherapeutic keratectomy, alcohol application, removal of the corneal cap, and penetrating keratoplasty (PKP). Outcomes ranging from retention of preoperative best corrected visual acuity to the need for PKP reflect the wide disparity in the severity of this complication and the therapeutic interventions required. CONCLUSION: Epithelial ingrowth is a relatively uncommon complication following LASIK. Suggestions for prevention and treatment are made.

Recutting the cornea versus lifting the flap: comparison of two enhancement techniques following laser in situ keratomileusis.

PURPOSE: To evaluate enhancement techniques following laser in situ keratomileusis (LASIK). METHODS: Recutting was performed on 263 eyes and the flap was lifted in 55 eyes that had LASIK for simple myopia or myopic astigmatism. The time interval between LASIK and retreatment was 340+/-46 days (range, 270 to 892 days) in the recutting group and 215+/-36 days (range, 53 to 617 days) in the flap lifting group. Mean spherical equivalent refraction, refractive cylinder, uncorrected and best spectacle-corrected visual acuity were examined prior to, and 1, 3, and 6 months after retreatment. RESULTS: Seventeen eyes were lost to follow-up in the lifting group and 53 eyes in the recutting group. In the recutting group, mean spherical equivalent refraction improved from -1.48+/-1.25 D to -0.49+/-0.88 D at 6 months. In the flap lifting group, mean spherical equivalent refraction improved from -1.05+/-1.49 D to -0.45+/-0.39 D at 6 months. Refractive cylinder did not change significantly in either group (P = .2). There was a significant increase in uncorrected visual acuity (UCVA) of 6/6 in each group. In the recutting group, UCVA of 6/6 increased from 3.8% to 65.2% at 6 months, and in the lifting group from 3.6% to 71.1% at 6 months. In the recutting group, seven free flaps and three macerated flaps that required removal occurred. One eye in the recutting group and two in the lifting group developed significant epithelial ingrowth. No patient lost more than one line of best spectacle-corrected visual acuity (BSCVA). CONCLUSION: Both procedures were safe, effective, and highly predictable for enhancements, but flap complications may be more likely with recutting.

Portsmouth POSSUM models for abdominal aortic aneurysm surgery.

BACKGROUND: The Portsmouth Physiological and Operative Severity Score for enUmeration of Mortality and morbidity (P-POSSUM) equation permits comparative audit that allows for differences in case mix. The methodology has previously been shown accurately to model general surgical and vascular surgical patients. Patients with a ruptured abdominal aortic aneurysm (AAA) are, however, very different from elective patients and it may be hypothesized that they require their own specific risk model. METHODS: POSSUM data on 444 (213 emergency, 231 elective) admissions for AAA surgery between August 1993 and July 2000 were analysed using the P-POSSUM equation for general surgery and the P-POSSUM equations developed for vascular surgery. RESULTS: All equations successfully modelled the elective aneurysms but failed to fit the emergency aneurysms, and the elective and emergency aneurysms combined. This suggested that admission method (not a POSSUM data item) is an important factor for patients with AAA. However, with these data it was not possible to generate a model, including admission method, that successfully modelled the combined elective and emergency data. The 213 emergency aneurysm repairs were divided into two groups by operation date. The first 106 (training set) were used to form logistic regression models following the P-POSSUM methodology. These models were found successfully to fit the remaining 107 records (test set) on prospective application (chi2 = 4.50, 4 d.f., P = 0.345). CONCLUSION: Ruptured AAAs appear to be different from elective AAAs and other vascular cases and require their own risk model.

Corneal deposition after high-dose chlorpromazine hydrochloride therapy.

PURPOSE: To report a case of dermal and ocular changes after prolonged use of high-dose chlorpromazine hydrochloride therapy. METHOD: This case report includes clinical history, clinical findings, and photographic images of ocular and dermal changes. RESULTS. Chlorpromazine therapy in a cumulative dosage exceeding 1,100 g resulted in dramatic skin discoloration and multiple crystalline deposits in both corneas. Anterior capsular opacities were binocularly present. These changes were sufficient to cause reduction in visual acuity. CONCLUSIONS: Chlorpromazine deposition at high levels can cause reduction in visual acuity and significant skin discoloration.

Successful treatment of Paecilomyces lilacinus endophthalmitis after foreign body trauma to the cornea.

PURPOSE: To report the successful treatment of a patient with Paecilomyces lilacinus endophthalmitis infection after foreign body (FB) trauma to the cornea. METHODS: A 30-year-old man presented to us with a corneal abscess and iritis 2 months after removal of a metal corneal FB. Initial corneal biopsy culture was negative. Treatment with topical 5% natamycin, 0.9% fortified gentamycin, and 5% cephalothin hourly was commenced. As a result of developing signs of endophthalmitis, two more biopsies were taken, a week apart, from the vitreous and anterior chamber, successively. The last biopsy yielded positive microbiologic results of the specious Paecilomyces lilacinus. Intravitreal injection of 50 microg/0.5 mL of amphotericin was administered during the vitreal biopsy. Soon after isolating the specious Paecilomyces lilacinus, the following treatment was administered: 200 mg of itraconazole bd by mouth, 5% topical natamycin every hour, 2 mg/mL of topical fluconazole every 2 hours, three anterior chamber injections of 0.35 mL of 0.1% fluconazole and two amphotericin B injections to the anterior chamber of 50 microg/0.5 mL each. RESULTS: There appeared to be no sign of infection 6 months after initial treatment. A large, dense scar existed in the medial part of the cornea only. The pupil was secluded. The patient's visual acuity was 6/21. The eye was comfortable and all topical antifungal medication was ceased.

LASIK for post penetrating keratoplasty astigmatism and myopia.

AIMS: To report the results of a series of patients who were treated with LASIK to correct post penetrating keratoplasty ametropia. METHODS: 26 eyes of 24 patients underwent LASIK to correct astigmatism and myopia after corneal transplantation; 14 eyes also received arcuate cuts in the stromal bed at the time of surgery. The mean preoperative spherical equivalent was -5.20D and the mean preoperative astigmatism was 8.67D. RESULTS: The results of 25 eyes are reported. The mean 1 month values for spherical equivalent and astigmatism were -0.24D and 2.48D respectively. 18 eyes have been followed up for 6 months or more. The final follow up results for these eyes are -1.91D and 2.92D for spherical equivalent and astigmatism. The patients undergoing arcuate cuts were less myopic but had greater astigmatism than those not. The patients receiving arcuate cuts had a greater target induced astigmatism, surgically induced astigmatism, and astigmatism correction index than those eyes that did not. One eye suffered a surgical complication. No eyes lost more than one line of BSCVA and all eyes gained between 0 and 6 lines UCVA. CONCLUSIONS: LASIK after penetrating keratoplasty is a relatively safe and effective procedure. It reduces both the spherical error and the cylindrical component of the ametropia. Correction of high astigmatism may be augmented by performing arcuate cuts in the stromal bed.

Staphylococcal infection under a LASIK flap.

PURPOSE: To report a staphylococcal infection under a laser in situ keratomileusis (LASIK) flap and to discuss the management of this rare and potentially devastating complication. METHODS: A patient was referred to our practice having had bilateral LASIK. She was found to have abscesses under the left corneal flap. Staphylococcus aureus was identified as the infecting organism by corneal scrape and treated with appropriate antibiotics. The cornea improved, and then the abscess recurred. The abscess was again scraped and intensive treatment reinstituted. RESULTS: After successful treatment, the patient recovered excellent visual acuity with only a minimal astigmatic error. CONCLUSION: The possible reasons for the apparent improvement and then recurrence of the abscess are discussed. The management of this case including the need for corneal scrape and antibiotic prophylaxis is discussed in relation to previously reported cases.

Toric laser in situ keratomileusis for myopic astigmatism using an ablatable mask.

BACKGROUND: To assess the results of toric laser in situ keratomileusis (LASIK) correction of myopic astigmatism. METHODS: A prospective study was performed over a 20 week period for consecutive patients treated for myopic astigmatism. Spectacle-corrected visual acuity, uncorrected visual acuity, spectacle refraction, videokeratography, and complications were recorded. Vector analysis was performed by the ASSORT program. RESULTS: Sixty-five eyes of 42 patients underwent toric LASIK with a Summit Technologies Apex Plus excimer laser. Mean preoperative spherical equivalent refraction at the spectacle plane was -6.24 +/- 2.42 D (range, -1.63 to -14.63 D) and mean pre-operative refractive cylinder magnitude was 1.99 +/- 1.35 D (range, 0.75 to 7.00 D); mean attempted refractive cylinder correction was 1.90 +/- 1.00 D. Six months after LASIK (43 eyes followed), mean spherical equivalent refraction at the spectacle plane was -0.40 +/- 0.55 D and 31 eyes (72.1%) were within +/- 0.50 D of emmetropia. At 6 months, mean refractive cylinder magnitude was 0.74 +/- 0.70 D, mean surgically induced astigmatism was 1.46 +/- 0.86 D, mean absolute angle of error was 10.33 degrees, mean astigmatic correction index was 0.93 +/- 0.36 D, and mean index of success was 0.46 +/- 0.39. Uncorrected visual acuity was 6/12 or better in 34 eyes (79.1%) and 6/6 in 15 eyes (35%); spectacle- corrected visual acuity was 6/9 or better in 41 eyes (95.35%). Six eyes (14.0%) lost 1 line of spectacle-corrected visual acuity at 6 months and one eye (2.3%) lost 2 lines. Ten eyes (23.3%) gained 1 line at 6 months. CONCLUSION: Toric LASIK with an ablatable mask using the Summit Apex Plus excimer laser is a safe and relatively accurate procedure for the correction of myopic astigmatism.

Ring keratitis from topical anaesthetic misuse.

BACKGROUND: Topical anaesthetic abuse is now an established differential diagnosis of ring keratitis. Published evidence suggests that this condition often has a poor prognosis, with the eyes sometimes requiring penetrating keratoplasty or the patient becoming blind. METHOD: A case of topical anaesthetic abuse and its subsequent management is presented. Ocular examination including pachymetry and specular microscopy is reported. RESULTS: The cornea made an excellent recovery, allowing a visual acuity of 6/6. Pachymetry showed corneal thickening and specular microscopy demonstrated a decreased cell count in the affected eye. CONCLUSIONS: With prompt recognition and appropriate treatment the prognosis for these cases can be excellent. However, there is evidence to suggest permanent cellular damage to the endothelium.

Central focal interface opacity after laser in situ keratomileusis.

BACKGROUND: The acute onset of a focal central interface opacity with visual loss following LASIK has not been described in the peer reviewed literature. Non-peer reviewed reports of various inflammatory lesions have been recorded. METHODS: We describe three cases in which an acute focal stromal interface opacification was identified within 1 week of laser in situ keratomileusis (LASIK). Each case was performed by a different surgeon on a different day, but using the same method, materials, and the Summit Apex Plus excimer laser. Immediately after surgery, all eyes were normal with good unaided vision. The appearance of the central stromal opacity was associated with acute visual deterioration. Preoperative and postoperative cycloplegic refractions, videokeratography, and postoperative slit-lamp biomicroscopy were performed. Each case was treated with intensive topical corticosteroids. RESULTS: Each case demonstrated a central circular opacity in the interface between corneal flap and stromal bed, with associated variable stromal thinning. Resolution of the pathological process followed 2 to 4 weeks of treatment with topical corticosteroids and subsequent improvement in slit-lamp biomicroscopy, corneal topography, and vision. Etiology was uncertain. CONCLUSION: Central interface opacification is a rare but visually important inflammatory complication of LASIK.

Audit of 149 consecutive carotid endarterectomies performed by a single surgeon in a district general hospital over a 12-year period.

Carotid endarterectomy has been established by two large randomised controlled trials (European Carotid Surgery Trial (ECST) and North American Symptomatic Carotid Endarterectomy Trial (NASCET)) as an important surgical procedure for the prevention of ischaemic strokes in patients presenting with transient cerebral ischaemia or non-disabling strokes attributable to severe ipsilateral carotid artery stenosis. The operation carries significant risk of death and stroke and it has been advocated by some that carotid endarterectomy should only be performed in a small number of designated regional centres in order to achieve good surgical results. It is doubtful that the regional centres alone can cope with the increasing numbers of patients requiring carotid endarterectomy and there is therefore a requirement for the procedure to be carried out by vascular surgeons in district general hospitals. It is important that surgical results are audited to ensure that comparable outcomes are achieved. We present an audit of our experience of carotid endarterectomy since 1981. A total of 149 consecutive carotid endarterectomies were performed by a single surgeon with a special interest in carotid surgery. The results are comparable to ECST with a 30-day mortality of 0% and an overall 30-day stroke rate of 5.7% (major strokes) for patients with severe, ie 70-99%, ipsilateral carotid artery stenoses. We have shown that carotid endarterectomy is an operation that can be performed safely and with good results by suitably trained surgeons in district general hospitals.

Clinical evaluation of percutaneous insertion and long-term usage of a new cuffed polyurethane catheter for central venous access.

A new, long-term venous access catheter was evaluated in clinical practice and the insertion time, complication rate and prospective follow-up recorded. Fifty novel polyurethane catheters (Cuff-Cath) were inserted in 48 patients, for cytotoxic chemotherapy in 36, long-term total parenteral nutrition in five and miscellaneous indications in seven. All catheters were inserted by a percutaneous technique under local anaesthesia. The mean insertion time was 18 min. There were three insertion complications; failure to cannulate, pneumothorax and malposition. Seven catheters required removal (sepsis in five, subclavian vein thrombosis in two) and one catheter fell out. Total catheter days to date has been 6607 (mean 132, range 18-831 days). Eleven catheters are still in use a mean of 154 days (range 38-490 days) after insertion. Furthermore, a new technique has been described which prevents inadvertent displacement. This new catheter combines the mechanical advantages of polyurethane, together with those of a Dacron cuff. Early results suggest that this catheter may be a useful alternative to silicone catheters of the Hickman/Broviac type for long-term central venous access.

Audit of 200 consecutive aortic aneurysm repairs carried out by a single surgeon in a district hospital: results of surgery and factors affecting outcome.

It has been suggested that surgery for abdominal aortic aneurysm (AAA) be confined to designated centres. A prospective audit of 200 consecutive AAA repairs at a district general hospital was performed between 1981 and 1990. The 30-day mortality rates for elective, symptomatic and ruptured aneurysm repair were 1.4%, 3.5% and 30%, respectively. The major factor affecting outcome after the mode of presentation was the age of the patient, with 30-day mortality rates for emergency treatment increasing from 21% (age range 60-69 years) to 42% (age range 70-79 years). This mortality rate for ruptured aneurysms is an underestimate, with two-thirds of patients with rupture dying before reaching hospital and some patients dying in hospital undiagnosed. The major contribution to improved overall mortality would therefore be detection before rupture (usually by ultrasound) and improved diagnostic accuracy. Many patients with ruptured aneurysms had symptoms for only a short period before presentation (42% for less than 6 h) and required urgent surgery (26% reached theatre within 1 h). These two factors make long-distance transfer of these patients an unrealistic option. The concentration of this type of surgery in relatively few centres will distance the patient from their relatives and reduce the opportunity for the majority of junior doctors to acquire an understanding of the presentation, natural history and management of aortic aneurysms. This understanding when combined with a screening programme is likely to have a far greater impact on the overall mortality from AAA than restricting the centres for surgical treatment.