Chorioretinal vascular oxygen tension in spontaneously breathing anesthetized rats.

PURPOSE: To establish baseline and variability of oxygen tension (PO(2)) measurements in the choroid, retinal arteries, capillaries, and veins of spontaneously breathing anesthetized rats and determine the effect of a moderate surgical procedure on the chorioretinal PO(2). METHODS: Our previously established optical section phosphorescence imaging technique was utilized to measure PO(2) in the chorioretinal vasculatures. Imaging was performed in 29 spontaneously breathing rats under ketamine/xylazine anesthesia. In 7 rats, blood was drawn using a surgically implanted femoral arterial catheter and analyzed to determine the systemic arterial PO(2). The PO(2) measurements in 22 rats without surgery (group 1) and 7 surgically instrumented rats (group 2) were statistically compared. The intrasubject variability was calculated by the average standard deviation (SD) of repeated measurements. RESULTS: The average systemic arterial PO(2) was 52 +/- 7 mm Hg (mean +/- SD) in group 2. In group 1, the average PO(2) measurements in the choroid, retinal arteries, capillaries, and veins were 50 +/- 11, 40 +/- 5, 39 +/- 6, and 30 +/- 5 mm Hg, respectively. No statistically significant PO(2) differences in any of the chorioretinal vasculatures were found between the two groups (p > 0.4). The intrasubject variability was 3 mm Hg in the choroid, retinal arteries, capillaries, and veins. CONCLUSIONS: Chorioretinal PO(2) measurements in spontaneously breathing anesthetized rats have a relatively low variability, indicating that PO(2) changes due to various physiological alterations can be reliably assessed.

Macular thickness mapping in exudative age-related macular degeneration.

PURPOSE: To report the feasibility of retinal thickness mapping for evaluating thickness differences in retinal areas with and without leakage shown by fluorescein angiography for patients who have age-related macular degeneration with choroidal neovascularization. METHODS: A custom-built version of the retinal thickness analyzer was used for thickness mapping. Retinal thickness was defined as the separation between vitreoretinal and pigment epithelium-choroid interfaces. Imaging was performed in 1 eye of 10 patients with the clinical diagnoses of age-related macular degeneration and choroidal neovascularization. Patients either had never undergone photodynamic therapy at the time of measurement (untreated) or had received one or more photodynamic therapy treatments (treated). Average retinal thicknesses in selected areas with and without the presence of leakage shown by fluorescein angiography were calculated and compared statistically. RESULTS: Retinal thickness (mean +/- SD) in areas with leakage (315 +/- 54 microm) was significantly greater than that in areas without leakage (280 +/- 28 microm) (P = 0.03). In untreated patients, areas with leakage (345 +/- 45 microm) were significantly thicker than areas without leakage (289 +/- 23 microm) (P = 0.02). In treated patients, retinal thickness in areas with leakage (271 +/- 33 microm) and without leakage (267 +/- 34 microm) was similar. CONCLUSION: Retinal thickness mapping may prove to be useful as an adjunct to fluorescein angiography to monitor choroidal neovascularization and its treatment.

Surgical management of acute sigmoid diverticulitis.

PURPOSE: To determine the frequency of use of resection and primary anastomosis in the management of acute sigmoid diverticulitis at Royal Columbian Hospital. METHODS: A retrospective chart review of all patients undergoing emergency surgery for acute sigmoid diverticulitis between 1989 and 2000 at the Royal Columbian Hospital, New Westminster, BC, was carried out in order to determine the frequency of resection and primary anastomosis. Patients who underwent bowel preparation were excluded. RESULTS: Ninety-seven cases met the criteria. There were 33 cases of resection and primary anastomosis (34%). Five of these cases were protected with a proximal diverting stoma giving an incidence of 85% unprotected primary anastomosis in a group of patients undergoing emergency surgery for acute sigmoid diverticulitis. There was 1 anastomotic leak, 7 wound infections, and 3 deaths with an average length of stay of 9 days. CONCLUSIONS: The practice of resection and primary anastomosis for acute sigmoid diverticulitis at the Royal Columbian Hospital has an acceptable morbidity and mortality.

Retinal topography and thickness mapping in atrophic age related macular degeneration.

AIM: To determine the relation between alterations in the retinal topography and thickness, visual acuity, and retinal pigment epithelium hypopigmentation in atrophic age related macular degeneration (AMD). METHODS: 22 patients, mean age 74 (SD 8) years, with atrophic AMD were recruited. An optical imaging system based on the retinal thickness analyser (RTA) was applied to generate a series of 20 optical section images that encompass 2 mm x 2 mm retinal areas. The optical section images were digitised and analysed to provide topographic maps of the vitreoretinal and chorioretinal surfaces and the retinal thickness. Vitreoretinal and chorioretinal surface elevations and retinal thickness were determined. RESULTS: Variation in the vitreoretinal surface height was moderately correlated with visual acuity (r = -0.4; p = 0.03; n = 22). Increase in variation of chorioretinal surface height was correlated with decrease in visual acuity (r = -0.5; p = 0.01; n = 22). The retinal thickness was not associated with visual acuity (r = 0.2; p = 0.2; n=22). Relative height of the vitreoretinal surface in eyes with retinal pigment epithelium (RPE) hypopigmentation was significantly less than eyes without RPE hypopigmentation (p = 0.005). Eyes with and without RPE hypopigmentation had a similar relative height of the chorioretinal surface (p = 0.4). Retinal thickness in eyes with RPE hypopigmentation was less than in eyes without RPE hypopigmentation (p = 0.04). CONCLUSION: Mapping of chorioretinal and vitreoretinal topography and retinal thickness provides objective and quantitative measurements of retinal structural abnormalities and shows promise as an adjunct for the evaluation of retinal structural changes due to AMD.

Dietary fat and risk for advanced age-related macular degeneration.

OBJECTIVE: To evaluate the relationship between intake of total and specific types of fat and risk for advanced age-related macular degeneration (AMD), the leading cause of irreversible blindness in adults. DESIGN: A multicenter eye disease case-control study. SETTING: Five US clinical ophthalmology centers. PATIENTS: Case subjects included 349 individuals (age range, 55-80 years) with the advanced, neovascular stage of AMD diagnosed within 1 year of their enrollment into the study who resided near a participating clinical center. Control subjects included 504 individuals without AMD but with other ocular diseases. Controls were from the same geographic areas as cases and were frequency-matched to cases by age and sex. MAIN OUTCOME MEASURES: Relative risk for AMD according to level of fat intake, controlling for cigarette smoking and other risk factors. RESULTS: Higher vegetable fat consumption was associated with an elevated risk for AMD. After adjusting for age, sex, education, cigarette smoking, and other risk factors, the odds ratio (OR) was 2.22 (95% confidence interval [CI], 1.32-3.74) for persons in the highest vs those in the lowest quintiles of intake (P for trend,.007). The risk for AMD was also significantly elevated for the highest vs lowest quintiles of intake of monounsaturated (OR, 1.71) and polyunsaturated (OR, 1.86) fats (Ps for trend,.03 and.03, respectively). Higher consumption of linoleic acid was also associated with a higher risk for AMD (P for trend,.02). Higher intake of omega-3 fatty acids was associated with a lower risk for AMD among individuals consuming diets low in linoleic acid, an omega-6 fatty acid (P for trend,.05; P for continuous variable,.03). Similarly, higher frequency of fish intake tended to reduce risk for AMD when the diet was low in linoleic acid (P for trend,.05). Conversely, neither omega-3 fatty acids nor fish intake were related to risk for AMD among people with high levels of linoleic acid intake. CONCLUSION: Higher intake of specific types of fat--including vegetable, monounsaturated, and polyunsaturated fats and linoleic acid--rather than total fat intake may be associated with a greater risk for advanced AMD. Diets high in omega-3 fatty acids and fish were inversely associated with risk for AMD when intake of linoleic acid was low.

Findings on retinal topography and thickness mapping in age-related macular degeneration.

PURPOSE: To report alterations in the retinal topography and thickness in typical cases of age-related macular degeneration (ARMD). METHODS: An optical imaging system was applied to patients with ARMD with alterations in the retinal structures. The system generates a series of 20 optical section images that encompass a 2 mm x 2 mm retinal area. The optical sections are digitized and analyzed to provide topographic maps of the vitreo-retinal and chorio-retinal surfaces and the retinal thickness. RESULTS: Retinal topography and thickness mapping in a normal eye corresponded to normal anatomy. Topographic mapping in a patient with confluent drusen indicated elevation of the vitreo-retinal surface. Retinal topography in a patient with retinal pigment epithelium detachment displayed localized elevation of the chorio-retinal surface. The thickness map in a patient with geographic atrophy of the retinal pigment epithelium revealed retinal thinning. In the patients with choroidal neovascularization, the vitreoretinal and chorio-retinal surfaces were elevated. The chorio-retinal surface map in a patient with evolving disciform scar displayed topographic variations corresponding to the fibrovascular tissue underlying the serous detachment. CONCLUSION: Retinal topography and thickness mapping is useful for visualization and evaluation of pathologic alterations in retinal structures due to ARMD.

Ocular oxygen consumption during vitreoperfusion in the cat.

PURPOSE: Little is known about the total ocular oxygen consumption rate (QO2) in human diseases. Reductions in QO2 may indicate the amount of tissue loss produced by conditions such as retinal ischemia. We sought a method to estimate QO2 that eventually could be used in patients during vitrectomy surgery. METHODS: We performed vitreoperfusion (perfusion of the vitreous cavity after vitrectomy) in 22 cat eyes with no ocular blood flow. The solution contained nutrients and a high partial pressure of oxygen (PO2). In 8 eyes we placed an oxygen electrode on the sclera, choroid, or outer retina to evaluate oxygen delivery from the vitreoperfusion solution (group 1). In 8 eyes the retinas were undisturbed (group 2), and in 6 eyes we excised the retinas (group 3). In groups 2 and 3 we estimated QO2 from the temporal decline of PO2 in the vitreoperfusion solution according to a pharmacokinetic model. RESULTS: Group 1 demonstrated oxygenation of the entire retina. The means and standard deviations of QO2 were 3.2 +/- 0.8 and 0.4 +/- 0.7 microL/min in groups 2 and 3, respectively, the difference being the retinal contribution, 88%. In group 2, metabolism accounted for an average of 82% of the oxygen loss from the vitreoperfusion solution, whereas flow and diffusion accounted for 13% and 5%, respectively. CONCLUSIONS: Ocular oxygen consumption can be estimated by means of vitreoperfusion. Further developments may allow measurements in patients during vitreous surgery to clarify the pathophysiology of their diseases and assess the amount of retinal tissue that has been lost.

Aqueous and vitreous penetration of levofloxacin after oral administration.

OBJECTIVE: To investigate the penetration of levofloxacin, an optical S-(-)isomer of ofloxacin, into the aqueous and vitreous humor after oral administration. DESIGN: Randomized, clinical trial comparing tissue levels of levofloxacin after one or two doses 12 hours apart. PARTICIPANTS: Forty-five patients undergoing initial vitrectomy between February 1997 and June 1997 at the UIC Eye Center. METHODS: Aqueous, vitreous, and serum samples were obtained and later analyzed from 45 patients after oral administration of 1 500-mg tablet (group 1, 22 patients) or 2 500-mg tablets (group 2, 23 patients) 12 hours apart before surgery. MAIN OUTCOME MEASURES: Aqueous, vitreous, and serum concentrations of levofloxacin (micrograms/milliliter). RESULTS: Group 1 achieved mean aqueous, vitreous, and serum levels of 0.59 +/- 0.48 microg/ml, 0.32 +/- 0.34 microg/ml, and 4.34 +/- 3.59 microg/ml, respectively. Group 2 achieved mean aqueous, vitreous, and serum levels of 1.90 +/- 0.97 microg/ml, 2.39 +/- 0.70 microg/ml, and 8.02 +/- 3.14 microg/ml. CONCLUSIONS: Mean inhibitory aqueous and vitreous MIC90 levels were achieved against a majority of ocular pathogens, including Staphylococcus aureus and Staphylococcus epidermidis, Streptococcus pneumoniae (vitreous), Bacillus cereus (vitreous), Haemophilus influenzae, Moraxella catarrhalis, and most gram-negative aerobic organisms except Pseudomonas aeruginosa after two doses given 12 hours apart. Mean MIC90 levels were obtained in the vitreous for a majority of pathogens responsible for traumatic, postoperative, or bleb-related endophthalmitis.

Outcome of vitreoretinal surgery and penetrating keratoplasty using temporary keratoprosthesis.

PURPOSE: The use of a temporary keratoprosthesis has allowed earlier surgical intervention in eyes with coexisting vitreoretinal and corneal disease. We analyzed our experience with this type of surgery. METHODS: We retrospectively reviewed charts of patients in whom a temporary keratoprosthesis was used between 1987 and 1998. Analysis was focused on ocular history, indications for surgery, visual acuity (VA), intraocular pressure, anatomic results, and complications. RESULTS: A temporary keratoprosthesis was used in 31 eyes, 22 (71.0%) of which were for trauma-related indications. In 6 (19.4%) of the operated eyes, the fellow eye also had severely reduced VA. Retinal detachments were present in 30 (96.8%) eyes; most had evident proliferative vitreoretinopathy. Twelve (38.7%) eyes had vitreous hemorrhage, and 20 (64.5%) had corneal scars. Improvement in VA was seen initially in 45.1% of patients, and 51.6% maintained equal or better VA at their final visit as compared with before surgery. The common documented reasons for poor final VA were recurrent retinal detachments deemed inoperable (32.3%), phthisis (22.6%), and optic atrophy or macular scar (16.1%). Corneal grafts remained clear in 41.9%. Nine patients had further surgery. The most significant complication was one case of sympathetic ophthalmia. CONCLUSIONS: Combined vitreoretinal and corneal surgery using temporary keratoprostheses has been used in our institution to treat eyes with extreme abnormalities. Outcomes were less favorable than some reported in the literature, probably because of the severity of disease for which temporary keratoprostheses were reserved. Although results are probably better than the natural course of the disease, patients should be informed of realistic expectations for improvement and potential complications when offered this option.

Hierarchical decomposition of laparoscopic procedures.

The purpose of this report is to outline the hierarchical decomposition of surgical procedures, from surgical steps through tasks and subtasks to tool motions, and highlight implications for surgical training systems. Three common laparoscopic procedures were analysed: cholecystectomy, inguinal hernia repair, and Nissen fundoplication. In laparoscopic training workshops and operating rooms, our observational research included split screen videotaping of both the endoscopic view and our video camera's view of the primary surgeon. Videotapes were extensively annotated and analysed to yield timelines of each procedure, with component surgical steps, substeps, tasks, and subtasks duration as a function of procedure. The hierarchical decomposition of surgical procedures provides a framework for structuring a systematic approach to training, in the real and simulated environment. An example comparing variations in the fundoplication procedure is presented. Our results also have important implications for the design and assessment of new technology and intelligent tools in endoscopic surgery.

Clinical course of macular holes: the Eye Disease Case-Control Study.

OBJECTIVE: To describe the clinical course of affected and unaffected eyes in patients with idiopathic macular holes. PATIENTS: Prospective study of patients with macular holes enrolled in the Eye Disease Case-Control Study. MAIN OUTCOME MEASURES: The best-corrected visual acuity at follow-up was compared with that at baseline. Changes in the macular holes, including increases in size or spontaneous regression, were assessed. The rates of development of new macular holes in fellow unaffected eyes were estimated. RESULTS: Of the 198 patients examined at baseline, 28 (14.1%) died before reevaluation. Of those who survived, 122 (71.8%) had a follow-up examination. Approximately 34% (34.4%) of all eyes with macular holes had an increase in the size of the macular hole. Forty-five percent of eyes had a decrease in visual acuity of 2 or more lines and 27.8%, of 3 or more lines; 40.9% remained stable, with a gain or loss of fewer than 2 lines. The rate of development of a new macular hole during follow-up in fellow eyes that were unaffected at baseline was 4.3% for 3 or fewer years of follow-up, 6.5% for 4 to 5 years of follow-up, and 7.1% for 6 or more years of follow-up. Spontaneous regression of the macular hole occurred in 3 (8.6%) of 35 patients with a follow-up interval of 6 or more years, whereas no regression occurred in patients with a shorter follow-up. CONCLUSIONS: The visual acuity of 45.0% of eyes with macular holes deteriorated by 2 or more lines during follow-up. The rate of development of macular holes in unaffected fellow eyes was low.

Clinical assessment of the macula by retinal topography and thickness mapping.

PURPOSE: To report a quantitative and objective method for assessing pathologic alterations in retinal structures to improve the evaluation of macular diseases. METHODS: We used a system based on the scanning retinal thickness analyzer to generate serial optical section images of the retina and provide mapping of the retinal topography and thickness in a normal subject and in patients with representative maculopathies including traumatic macular hole, central serous chorioretinopathy, branch retinal vein occlusion, diabetic macular edema, and retinal pigment epithelial detachment. RESULTS: The effectiveness of the system in imaging both the vitreoretinal and chorioretinal interfaces was confirmed in the normal subject and in patients with various maculopathies. Mapping of retinal topography and thickness in a normal eye correlated well with normal anatomy, delineating the foveal depression clearly. The retinal thickness map in a patient with diabetic macular edema showed thickening of the retina and absence of a foveal depression. The patients with central serous chorioretinopathy and branch retinal vein occlusion had an elevated vitreoretinal surface. Conversely, the patient with retinal pigment epithelial detachments had a relatively flat vitreoretinal interface but an irregularly elevated chorioretinal surface. CONCLUSION: Quantitative mapping of retinal topography and thickness is a promising tool that may improve evaluation of macular diseases.

Is wound infiltration with anesthetic effective as pre-emptive analgesia? A clinical trial in appendectomy patients.

OBJECTIVE: To assess the efficacy of wound infiltration with local anesthetic in reducing postoperative pain after a muscle-splitting incision for appendectomy. DESIGN: A double-blind, placebo-controlled, randomized clinical trial. SETTING: The Royal Columbian Hospital, a university-affiliated community hospital. PARTICIPANTS: Forty-three patients scheduled to undergo emergency appendectomy were randomized into treatment (21) and control (22) groups. Five patients were excluded from the treatment group. INTERVENTIONS: Local anesthetic infiltration of the wound before incision (treatment group) and saline infiltration (control group). MAIN OUTCOME MEASURES: Postoperative analgesic requirements, pain assessment by visual analogue scale and length of hospital stay. RESULTS: No significant difference in analgesic use was seen between the 2 groups, as measured at 3 stages (Mc = control mean [standard deviation], Mt = treatment mean [standard deviation]): (a) in the recovery room, intravenous morphine use was Mt = 6.6 mg [8.6] v. Mc = 10.1 mg [7.2]; (b) in the first 2 postoperative days, intramuscular meperidine use was Mt = 309 mg [181] v. Mc = 278 mg [125] on day 1 and was Mt = 121 mg [132] v. Mc = 97 mg [128] on day 2; (c) in the final 5 days of follow-up, oral analgesic use was Mt = 11 [17] tablets v. Mc = 21 [16] tablets (acetaminophen with codeine). Pain assessments at rest, on a scale of 1 to 10, were found to be no different between groups, ratings being Mt = 4.7 [2.1] v. Mc = 4.5 [2.0] on day 1. Length of hospital stay averaged 3.0 days in both groups. CONCLUSIONS: Infiltration with local anesthetic before incision does not pre-empt postoperative pain from a muscle-splitting incision used for appendectomy.

Illustration of the stages of idiopathic macular holes by laser biomicroscopy.

BACKGROUND: The determination of the developmental stage of macular holes is difficult to assess clinically. This may be the reason for the conflicting reports on the risk of vision loss in patients with macular holes and on the value of prophylactic surgery. We have developed a new method, laser biomicroscopy, which provides visualization and photographic record of vitreoretinal structures at the macula. OBJECTIVE: To test the applicability of this method to the identification of macular holes stages. METHODS: Laser biomicroscopy and slit-lamp biomicroscopy were used to examine 18 patients with macular holes, identify the lesions, and classify them according to the various stages of development of idiopathic macular holes as proposed by Gass. RESULTS: Reflections considered to originate from the hyaloid membrane were observed more frequently by laser biomicroscopy than by conventional slit-lamp biomicroscopy. Two fellow eyes were diagnosed by laser biomicroscopy as having stage 1 lesions while slit-lamp biomicroscopy failed to yield a clear diagnosis. In four eyes with stage 3 holes the vitreoretinal separation was apparent only on laser biomicroscopy. Four cases were selected to illustrate the laser biomicroscopic findings in the different stages of macular hole development. CONCLUSIONS: The ease of visualization of the macular lesions with laser biomicroscopy may facilitate the evaluation of the early stages of macular holes and reduce the incidence of misdiagnosis. Furthermore, photographs obtained by laser biomicroscopy may be a useful tool in studies of early stages of macular holes.

Perforation of the small bowel: a case report.

Nontraumatic perforation of the small bowel is rare. A 71-year-old man presented with a perforated jejunum 8 weeks after receiving streptokinase therapy for acute myocardial infarction. This was complicated by a bleeding duodenal ulcer, renal failure, ischemia of one toe and confusion. Renal biopsy showed cholesterol emboli. Examination of the resected specimen of jejunum revealed multiple cholesterol emboli but no other disorder. Cholesterol embolization has been associated with angiography, vascular surgery and thrombolytic therapy for myocardial infarction. Acute renal failure and ischemia of the digits as seen in this patient is also a common presentation of cholesterol embolization syndrome.

Retinal thickness change after focal laser treatment of diabetic macular oedema.

Laser photocoagulation has been used successfully for the treatment of clinically significant macular oedema to reduce the risk of loss of vision in diabetic patients. A quantitative method for measuring retinal thickness was applied to 20 patients with diabetic macular oedema before and 4 months after focal laser treatment to assess the reduction in retinal thickening and its relation to visual acuity. The degree of thickening at each location, defined by thickness index, was determined relative to the corresponding average value in normal subjects. Comparison of quantitative retinal thickness measurements before and after treatment demonstrated that treatment at thickness indices of approximately 1.6 (60% thickening) has nearly 50% probability for reversal of thickening to within the normal range (< or = 1.3), whereas at thickness indices greater than 2.8 (180% thickening) there is less than 2.5% probability that reversal will occur. The level of foveal thickening before treatment strongly correlated with the degree of thickening after treatment. Most of the eyes with an improvement in visual acuity had a foveal thickness within the normal range at 4 months' follow up. These findings suggest that quantitative retinal thickness measurement provides an objective assessment of the degree of macular oedema and can be useful for monitoring the efficacy of focal laser treatment in reducing the thickening and relating the latter to visual outcome.

Enhanced visualization of vitreoretinal interface by laser biomicroscopy.

BACKGROUND: The use of slit-lamp biomicroscopy provides valuable information for the diagnosis and management of vitreoretinal disorders. However, intense backscatter from the fundus often precludes the visualization of fine structures in the vitreoretinal interface. METHODS: Laser biomicroscopy is a new method designed to improve the visualization of fine vitreoretinal structures at the macula. This method was applied to eyes suspected of traction maculopathies. With this method, the contrast and the lateral separation between the vitreal and retinal images are optimized while preserving information on the location of the slit on the fundus. RESULTS: The results indicated that fine structures in the vitreoretinal interface, which were difficult to observe with conventional slit-lamp biomicroscopy, could be clearly visualized. CONCLUSION: Laser biomicroscopy may be a useful tool in the diagnosis and management of diseases with vitreoretinal abnormalities.

Subretinal exudative deposits in central serous chorioretinopathy.

The presence of subretinal exudation in a patient with neurosensory detachment of the macula frequently suggests the diagnosis of choroidal neovascularisation. A retrospective chart review of newly diagnosed cases of central serous chorioretinopathy revealed 11 patients, seven men and four non-pregnant women, who had plaques of subretinal exudate, which presumably were fibrin. Each of these patients had a solitary plaque that ranged in size from 300 to 1500 microns in diameter. These patients had no signs or a clinical course suggestive of choroidal neovascularisation. In each case the subretinal plaque was overlying an exuberant leak in the retinal pigment epithelium. The exudate was generally present at the initial examination, and usually showed dissolution before or coincident with the resolution of the neurosensory detachment. After resolution of the central serous chorioretinopathy, patients were left with subtle alterations in the retinal pigment epithelium in the areas of the subretinal plaque. These findings are important for two reasons. Firstly, the presence of subretinal exudation does not necessarily rule out the diagnosis of central serous chorioretinopathy. Secondly, pathophysiological theories of central serous chorioretinopathy must explain how the plaques are deposited behind the retina.

Review of the pathologic diagnoses of 2,216 appendectomy specimens.

A retrospective review of 2,216 patients surgically treated for a clinical diagnosis of acute appendicitis was performed. In 80% of cases, histologic acute appendicitis was found; 57% of these patients were male. The rate of normal appendectomy was 16%, and females comprised 68% of that group. The remaining 102 cases (4%) were designated as the alternate diagnosis group. Apart from histologic diagnoses that could be considered variants of normal (57) or acute inflammation (20), the alternate diagnosis group included such entities as neoplasm, parasitic infection, mucocele, and diverticulitis.