Glenoid fossa fracture and condylar penetration into the middle cranial fossa: report of a case and review of the literature

PURPOSE: It has been suggested that hysterectomy has a disturbing influence on bowel function. To assess the incidence and nature of these changes, we performed a retrospective study. METHODS: A retrospective study was performed in all 593 women who had undergone hysterectomy between 1989 and 1993. A control group consisted of 100 women who had undergone laparoscopic cholecystectomy. RESULTS: The response rate was 90 percent (n = 531; median age, 45 (range, 18-84) years). Of the responding women, 315 patients (59 percent) indicated a normal defecation pattern before hysterectomy. Of these women, severe deterioration in bowel function was reported by 98 patients (31 percent), whereas 36 women (11 percent) mentioned a moderate change after hysterectomy. Most frequent symptoms were severe straining (90 patients), incomplete and/or digital evacuation (83 and 50 patients, respectively). According to most patients, the changes in bowel function were reported to have started within one month after hysterectomy. With advancing age, fewer complaints were recorded (P = 0.008). No significant difference was found in the incidence of disturbed bowel function between the different types of operation (abdominal, vaginal, supravaginal, or radical hysterectomy). In the control group, the response rate was 96 percent. Median age of these women was 46 (range, 25-78) years. Fifty-eight patients (60 percent) reported normal bowel function before laparoscopic cholecystectomy. In this group of patients, disturbed bowel function after surgery was reported by five women (9 percent), which figure is significantly (P < 0.001) lower compared with that in the corresponding hysterectomy group. CONCLUSION: Hysterectomy seems to play an important role in the pathogenesis of disturbed defecation.     

The impact of conventional proctocolectomy on sexual function

Seventy-one women who had a proctocolectomy for ulcerative colitis (n. 41) or Crohn's disease (n. 30) were interviewed in the follow-up clinic for gynaecological problems and fertility. Forty-nine per cent (35/71) of the women had a distressing vaginal discharge after proctocolectomy, compared with 9% before surgery. At the gynaecological examination 45% (32/71) had a heavy vaginal secretion without any signs of an acute vaginal infection. In 68% (30/44) fluid retention in the vagina was associated with a caudally firmly-fixed and dilated posterior vaginal fornix. Twelve per cent (8/66) of the women reported dyspareunia before surgery. After surgery, 27% (18/66) complained of this symptom. Fertility was significantly reduced after surgery since only 37% (10/27) of the women who attempted to become pregnant succeeded within five years follow-up. The corresponding figure before surgery was 72% (39/54). Those who conceived went through pregnancy and parturition without any incident, 6 of 24 delivered by cesarean section. Fifty-seven men who had a proctocolectomy for ulcerative colitis (n.41) or Crohn's disease (n. 30) were interviewed in the follow-up clinic for the presence of sexual disturbances and their incidence was studied. Fifty-seven per cent of elderly patients (above 40 years old) complained of reduced libido and sexual satisfaction. In younger patients (below 40 years old) 33% complained of an impaired quality of sexual life and 22% complained of an impaired sexual satisfaction. However, despite some sexual dysfunction, 56% reported improved sexual life and 67% improved sexual satisfaction. This may be explained by improved general health and increased libido after removal of diseased bowel.(ABSTRACT TRUNCATED AT 250 WORDS)     

Hysterectomy in a Danish population. Weight-related factors, psychological factors and life style variables

The aim was to assess risk factors for hysterectomy performed for benign conditions. In a prevalence study, 2301 Danish women were selected at random in 1982. Information about weight and slimming history, life-styles, psychological factors, gynaecological history, and social background were obtained. In an incidence study, the cohort was followed from 1982 to 1990 to assess the incidence of hysterectomy. In the prevalence study, weight cycling (recurrent weight loss and weight gain of more than 5 kg) was associated with hysterectomy for benign disease (adjusted odds ratio 1.77, 95% confidence interval 1.05-2.99) independently of overweight, smoking, oral contraceptives, psychological and social factors. In the incidence study, weight cycling was the only significant weight-related risk factor for hysterectomy performed for benign disease (adjusted relative risk 2.49, 95% confidence interval 1.10-5.60), explaining the relation between hysterectomy and psychological factors. Weight cycling might be an important risk factor for premenopausal hysterectomy performed for benign conditions.     

Complications after hysterectomy. A Danish population based study 1978-1983

We studied complications after hysterectomy among all women in the Danish population who had a simple hysterectomy in the period 1978-81 based on data obtained from the Danish National Hospital Registry. Among patients, with neither diagnosed cancer nor major co-surgery (n = 23,386), we identified all the complications which occurred during hospital admission from the time of surgery up to six years from that point. Within 30 days of hysterectomy 2.6% of the patients had been diagnosed in hospitals as having complications according to our definition. The corresponding figures at 90 days and two years after the operation were 3.7% and 9.4%. The most frequently observed complications were post operative wound infections and bleeding, each affecting about 2% of all operated women. Logistic regression and Cox regression were used to identify prognostic indicators of readmission with complications. The probability of readmission with complications within six years after hysterectomy was estimated at 8% among low risk patients. The most pronounced increase in risk of readmission with complication occurred among women who had been admitted to psychiatric or somatic hospitals 0-12 months before they had their uterus removed (OR in the range 1.59 to 1.83). We discuss the prevailing difficulties of comparing observational evidence from different clinical settings reported in the literature, and emphasize the importance of developing a coordinated international strategy for non-experimental assessment of medical technology.     

Medical thoracoscopy in the management of pneumothorax

In a general practice population of 11,300 patients, 223 were known to have diabetes mellitus. Thirteen diabetic patients (5.8%) had a previous diagnosis of thyroid disease. The study excluded 17 patients who received sole diabetes care at a secondary referral centre (of whom 5 had a previous diagnosis of thyroid disease), 8 with a previous diagnosis of thyroid disease receiving community care, and 1 patient who declined screening. New thyroid disease was diagnosed in 11 patients (8 female, 3 male): 5 with primary hypothyroidism, 4 with subclinical hypothyroidism, 1 with hyperthyroidism and 1 with subclinical hyperthyroidism. Thus the prevalence of undiagnosed thyroid disease in diabetic patients receiving community diabetes care was 5.5% (9.5% of female patients), and the prevalence of thyroid disease (previously known and diagnosed as a result of screening) in the entire population of diabetic patients registered in the general practice was 10.8%. These findings suggest that screening for thyroid disease should be considered in patients receiving diabetes care in the community.     

Placenta accreta: evaluation with color Doppler US, power Doppler US, and MR imaging

PURPOSE: To determine the value of transabdominal ultrasound (US), transvaginal US, color Doppler US, power Doppler US, and magnetic resonance (MR) imaging in the diagnosis of placenta accreta. MATERIALS AND METHODS: Nineteen patients in the third trimester of pregnancy who were at risk for placenta accreta underwent color Doppler and power Doppler US; 18 patients also underwent MR imaging. Images were interpreted prospectively for signs of accreta by two reviewers. The reviewers' confidence in their diagnosis was graded on a five-point scale. RESULTS: Outcomes at delivery were as follows: normal placenta (n = 11), hysterectomy owing to uncontrollable bleeding (n = 1), and placenta accreta (n = 7). Five cases of lower-uterine-segment placenta accreta were diagnosed with a high level of confidence with vaginal and power Doppler US. In one patient with a posterior placenta who had previously undergone myomectomy, MR imaging enabled the diagnosis of placenta accreta, which was not well depicted at US. CONCLUSION: In patients with a history of uterine scars, vaginal US with power Doppler US performed well in the evaluation of lower-uterine-segment placenta accreta. MR imaging depicts posterior placenta accreta.     

Prognostic factors in surgically treated small cell cervical carcinoma followed by adjuvant chemotherapy

BACKGROUND: Small cell carcinoma of the uterine cervix is an uncommon tumor associated with high mortality even among patients with early stage disease. The role of adjuvant chemotherapy after surgery has been suggested by regimens used for small cell lung carcinoma. During the years 1980-1997, 19 cases in which various adjuvant chemotherapies were given after hysterectomy were reported in the literature published in English. METHODS: Adjuvant chemotherapy was administered consecutively to 23 patients with Stage Ib-II small cell cervical carcinoma who had been primarily treated with radical hysterectomy and had adequate bone marrow, renal, and hepatic functions. A combination of vincristine, doxorubicin, and cyclophosphamide alternating with cisplatin and etoposide (VAC/PE) was administered to 14 patients during the years 1988-1996 according to a prospective study protocol. A combination of cisplatin, vinblastine, and bleomycin (PVB) was administered to 8 patients, and another regimen was administered to 1 patient during the years 1984-1988. Prognostic factors were evaluated by analyzing both the data on these 23 patients and the pooled data on the cases retrieved from the literature and our own files. RESULTS: Ten of the 14 patients who received VAC/PE had no evidence of disease during a median follow-up of 41 months, whereas 3 of the 9 who received PVB or another regimen survived. Of the 10 patients who died of their disease, all died of distant metastasis within 10 months after recurrence. Meta-analysis of the pooled data showed that 68% of patients who received regimens containing VAC or PE survived, whereas 33% of patients who received regimens not containing VAC/PE survived (P = 0.0078, log rank test). Seventy percent of patients with no lymph node metastasis at hysterectomy and 35% with lymph node metastasis survived (P = 0.05). All patients who died of disease had extrapelvic metastasis. CONCLUSIONS: Chemotherapies containing VAC or PE are favorable regimens for patients with early stage small cell cervical carcinoma after radical hysterectomy.     

Fullerene lipids: synthesis of dialkyl 1,2-[6,6]-methano-[60]-fullerene dicarboxylate derivatives

OBJECTIVE: To determine the prevalence of chronic arthritis with special reference to rheumatoid arthritis. METHOD: A cross-sectional study was performed during the years 1990 and 1991 in a randomly selected sample of the urban population of Belgrade. RESULTS: Out of 2184 participants, > or = 20 yr old, surveyed by questionnaire, 756 (34.6%) reported peripheral joint complaints. Of those with complaints, 621 (82.1%) agreed to undergo detailed examination. Arthritis was diagnosed in four men (one had rheumatoid arthritis and three had spondylarthropathy with peripheral arthritis) and 11 women (three had rheumatoid arthritis, one had B27-positive polyarthritis and seven had undifferentiated chronic arthritis). The prevalence of chronic arthritis in the adult population was 0.69% (0.35% for men and 1.05% for women). The prevalence for rheumatoid arthritis was 0.18% (0.09% for men and 0.29% for women). Re-examination of 15 individuals with chronic arthritis 3 yr later showed changes in diagnosis only in those patients who at baseline examination had undifferentiated chronic arthritis. CONCLUSION: According to the results obtained, the urban population of Belgrade is among populations with a low prevalence of rheumatoid arthritis.     

Latex allergy in patients with spinal dysraphism: the role of multiple surgery

OBJECTIVE: To investigate whether multiple surgery is responsible for the high prevalence of latex hypersensitivity in patients with spinal dysraphism by comparing the results of a skin-prick test in three groups of patients with different surgical histories. PATIENTS AND METHODS: An in vivo diagnostic kit was used to determine the sensitivity to latex using a skin-prick test in three groups of patients, 23 with spinal dysraphism who had undergone surgery, 20 patients who had undergone non-urological surgery and urological patients who had not undergone surgery (control). There was no history of latex allergy in any individual from the three groups. RESULTS: The skin-test was positive in six patients with spinal dysraphism, in one who had undergone previous non-urological surgery and in none of the control patients. The prevalence of latex hypersensitivity was significantly higher in patients with spinal dysraphism than in the other groups (non-urological surgery P < 0.05 and control P < 0.01). This difference occurred despite the patients in each surgical group having undergone a mean of less than two operations. There was no significant difference in latex sensitivity between control patients and those undergoing non-urological surgery. CONCLUSION: Despite having no history of latex hypersensitivity, about a quarter of patients with spinal dysraphism were sensitive to latex. Repeated surgery alone cannot be responsible for the greater incidence of latex hypersensitivity in these patients. Despite multiple surgery being accepted as playing a major role in the development of latex hypersensitivity, relatively fewer surgical episodes than reported previously seem to be sufficient to elicit latex allergy.     

Calciphylaxis in patients on hemodialysis: a prevalence study

BACKGROUND: Calciphylaxis is characterized by painful, violaceous, mottled skin lesions (livedo reticularis) that may progress to tissue necrosis, nonhealing ulcers, gangrene, and potentially amputation, sepsis, or death. The prevalence and characteristics of patients who have calciphylaxis need further identification to predict which patients on dialysis may benefit from close monitoring or early surgical intervention. METHODS: All 242 patients undergoing hemodialysis in an outpatient unit were reviewed retrospectively during a 15-month cross-sectional study of the prevalence and characteristics of calciphylaxis. RESULTS: Ten patients (prevalence, 4.1%) had calciphylaxis. Patients with calciphylaxis were significantly younger (49 versus 60 years; p = 0.01), had undergone hemodialysis longer (80 versus 20 months; p < 0.0001), and had higher median serum calcium (9.7 versus 9.2 mg/dl; p = 0.03), phosphate (8.2 versus 5.7 mg/dl; p = 0.001), calcium phosphate product (81.5 versus 52.9; p = 0.0004), parathyroid hormone (1496 versus 138 pg/ml; p < 0.0001), and alkaline phosphatase levels (188 versus 89 IU/L; p = 0.0001). Bone surveys were positive in all 10 patients with calciphylaxis compared with 49 (21%) of the 232 patients without calciphylaxis (p < 0.0001). All patients who underwent parathyroidectomy for calciphylaxis had dramatic healing of the ulcers. CONCLUSIONS: The presence of calciphylaxis is higher among younger patients who had undergone longer periods of hemodialysis. Therefore this group of patients should be monitored aggressively and treated expeditiously for complications of secondary hyperparathyroidism.     

Combined intramuscular-intradermal protocol of universal neonate HB vaccination irrespective of mother''s status of HBsAg

BACKGROUND: The usefulness of the rapid urease test (RUT) in diagnosing Helicobacter pylori infection after peptic ulcer surgery is unknown. METHODS: Patients who had undergone peptic ulcer surgery were offered endoscopic examination if they presented with dyspepsia or gastrointestinal bleeding. Biopsy specimens were taken for RUT and histology from the corpus and the stoma in patients who had undergone partial gastrectomy or from the corpus and the antrum in patients who had undergone vagotomy. Histologic examination using haematoxylin and eosin stain and Warthin-Starry stain were used as the gold standard. RESULTS: Ninety patients were studied (69 had partial gastrectomy and 21 had vagotomy). Forty-three patients (32 in the partial gastrectomy group and 11 in the vagotomy group) were positive for H. pylori by histology. The respective sensitivity of RUT was 59% (stoma) and 75% (corpus) in the partial gastrectomy group (P = 0.36) and 55% (antrum) and 73% (corpus) in the vagotomy group (P = 0.51). CONCLUSIONS: RUT is not sensitive for detecting H. pylori after acid reduction surgery.     

Hypophosphataemia in patients undergoing bone marrow transplantation

We studied the prevalence of hypophosphataemia (< 0.80 mmol/l) in seventeen patients who had undergone bone marrow transplantation (BMT). Thirteen (77%) of the seventeen patients had hypophosphataemia at some stage during the conditioning phase or after their BMT. Seven (41%) of the seventeen patients had hypophosphataemia in the peri-BMT period that is during the conditioning phase or within one week thereafter. Two of the patients showed severe hypophosphataemia (< 0.30 mmol/l). We suggest that plasma phosphate should be monitored in patients with a bone marrow transplant.     

Antibiotic prophylaxis of infectious complications in gynecologic surgery]

Infections are still the most frequent postoperative complications and one of the limiting factors of successful gynaecological surgery. In recent years information on successful anti-microbial chemoprophylaxis is increasing and is associated with reduced postoperative inflammations, febrile morbidity and early complications. Views differ above all as regards indications for the use of antibiotic prophylaxis and the selection of a suitable antibiotic. Data in the literature differ also as regards achieved results. The submitted work had the objective to test on a representative group the success and rationality of medicamentous prophylaxis in gynaecological surgery and to contribute to a clearer view on controversial points. 203 women admitted to the Second Gynaecological and Obstetric Department of the First Medical Faculty Charles University and General Faculty Hospital Prague for elective abdominal or vaginal hysterectomy on account of a benign indication were divided into three groups which did not differ from the demographic or medical aspect. In group A (53 women) for prophylaxis two doses of Augmentin were used (combination of amoxycillin with clavulanic acid) i.v., patients in group M (50 women) had three doses of Mandol (Cefamandol) i.m., and in control group K (100 patients) no antibiotics were administered prophylactically. The authors investigated the postoperative course and evaluated some parameters in relation to possible postoperative infectious complications. The results proved unequivocally that prophylaxis with Augmentin reduces significantly the postoperative infectious morbidity (11.5%), febrile morbidity (5.6%) and the incidence of early infectious complications (3.8%) after abdominal or vaginal hysterectomy, as compared with the control group (35%, 31% and 11% resp.). Prophylaxis with Cefamandol reduced only in few parameters postoperative complications, but in general did not lead to a significant improvement of the postoperative course nor to a reduction of postoperative inflammatory complications. Similar results were obtained when only complications after abdominal hysterectomy were evaluated. The results of bacteriological examination confirmed the expected differences in the spectrum of efficacy of the two antibiotics on the most common microbial flora in the given area, i.e. a high sensitivity of Augmention to enterococci and bacterioids and resistance of these bacteria to Mandol. These results can be considered one of the reasons of different results of the two antibiotics. Prophylaxis with amoxycillin/clavulanic acid was found to be safe, very effective and financially feasible prevention of postoperative infectious complications after abdominal and vaginal hysterectomy. It led to a significant increase in the number of cases without any complications, when compared with the control group.     

Mediastinal lymphadenopathy in cryptogenic fibrosing alveolitis: the effect of steroid therapy on the prevalence of nodal enlargement

PURPOSE: To determine the prevalence of enlarged mediastinal lymph nodes in cryptogenic fibrosing alveolitis (CFA) and to assess whether this frequency was related to steroid administration. MATERIAL AND METHODS: Retrospective review of chest radiographs and high-resolution computed tomography (CT) of 54 patients with proven cryptogenic fibrosing alveolitis (CFA). Twenty-two of the 54 patients received oral steroids up to 2 months before the time of high-resolution CT examination (group 1); the remaining 32 patients had not taken steroids for at least 6 months before study entry (group 2). The prevalence, distribution, and size of enlarged mediastinal lymph nodes was determined in all groups. The diagnosis of CFA was histologically established in 44 patients. In 10 patients the diagnosis of CFA was based on clinical and high-resolution CT findings. RESULTS: Mediastinal lymphadenopathy was present in 26 of 54 patients with CFA. The prevalence of enlarged nodes was 14% (three of 22) in patients who had received oral steroids up to 2 months before the time of CT examination, and 71% (23 of 32) in patients that had not taken steroids for at least 6 months before study entry. CONCLUSION: We conclude that patients with CFA on steroid therapy had a significantly lower prevalence of mediastinal adenopathy (P < 0.001) than patients who had not taken steroids.     

Treatment of radiotherapy-induced gastroparesis with erythromycin

HISTORY: A 75-year-old woman who had undergone a hysterectomy with adnexectomy followed by radiotherapy for endometrial carcinoma complained of postprandial nausea with vomiting after eating solid foods and of cramp-like abdominal pain, but her appetite was good. She had lost 25 kg in weight over 13 months. EXAMINATION: Physical examination, laboratory tests, radiology and gastroscopy were unremarkable. Gastric scintigraphy showed abnormally prolonged emptying. TREATMENT AND COURSE: Nausea and vomiting stopped at once after erythromycin (a motilin agonist) had been administered. It was at first given intravenously after meals (50 mg three times daily for 5 days), then orally for 10 weeks (250 mg three times daily before meals). Subsequent examination revealed normal gastric emptying. The symptoms did not recur after erythromycin had been discontinued. CONCLUSION: Erythromycin is an effective drug against gastroparesis caused by radiotherapy, because it acts even when the enteric nerves are damaged.     

Effect of ecological factors in an industrial city on the health of students

PURPOSE: To determine the prevalence of cytomegalovirus retinitis after cardiac transplantation. METHODS: Records of patients who had cardiac transplantation at Jackson Memorial Hospital between November 1986 and November 1994 were reviewed. Patients who had not previously had ophthalmic evaluation after transplantation were invited for retinal examination. RESULTS: Eighty-two patients had cardiac transplantation during the study period. One to 68 months (mean, 24.5 months) after transplantation, ophthalmoscopic examination was performed in 41 patients. Six (14.6%) of 41 patients had healed scars consistent with cytomegalovirus retinitis or active cytomegalovirus retinitis. CONCLUSIONS: Cytomegalovirus retinitis lesions were found in six (14.6%) of 41 patients. If remaining patients were unaffected and no patient developed cytomegalovirus retinitis after ophthalmoscopic examination, the prevalence would be 7.3% (6/82). We recommend ophthalmic screening of all patients 3 to 4 months after cardiac transplantation with repeat examinations yearly or as ocular symptoms occur.     

Coagulation factor abnormalities after the Fontan procedure and its modifications

OBJECTIVE: Recently we reported the prevalence of thromboembolism in patients who underwent the Fontan procedure and its modifications. Although hemodynamic factors may well contribute to thromboembolism, recent evidence suggests that coagulation factor abnormalities may also play a role. We therefore set out to investigate the coagulation status in a group of patients who had undergone the Fontan procedure. METHODS: The study population consists of 20 children who had undergone the Fontan procedure and its modifications. They were examined for coagulation factor abnormalities. Concentrations of serum albumin, total protein, and liver enzymes were also measured. The median age at the time of the operation was 6.2 years (17 months to 8 years) with a male/female ratio of 2.3:1. The median time from the Fontan repair was 4.9 years (18 to 76 months). RESULTS: Protein C (p < 0.001), protein S (p < 0.02), and factor VII (p < 0.001) were significantly lower than the normal range. The changes in serum albumin and total protein and factors II, IX, and X were not significant. CONCLUSIONS: It is possible that deficiency in protein C, protein S, and factor VII partly account for the prevalence of thromboembolism after Fontan-type repairs. The risk of long-term anticoagulation should be weighed against the best palliative procedure for these patients. We suggest that reduced protein C, protein S, and factor VII levels in this group of patients should be regarded as risk factors and that such patients should be treated with anticoagulants.     

Genital fistulas caused by diverticular disease of the sigmoid colon

OBJECTIVE: Our purpose was to bring to the attention of gynecologists a subject not mentioned in a single textbook of gynecology, namely, genital fistulas resulting from diverticular disease of the sigmoid colon. STUDY DESIGN: We report our experience with 13 genital fistulas caused by sigmoid diverticulitis. RESULTS: Ten fistulas involved the vagina, one the vagina and bladder, one the tube, and one the uterus. Average age of the patients was 68.6 years (range 54 to 89 years). Presenting symptom in 12 patients was a malodorous vaginal discharge. All with vaginal lesions had previously undergone total hysterectomy. A barium enema failed to demonstrate a fistula in 8 of 11 patients. Colonoscopy failed in 8 of 8 patients. All fistulas were demonstrated by retrograde dye studies. Ten patients operated on were cured. Three patients refused surgery; of these, 1 had intestinal obstruction, 1 may have had spontaneous closure of the fistula, and 1 is being observed. Surgery involved staged procedures in 2 patients, fistulectomy in 4, and bowel resection and anastomosis in 4. CONCLUSIONS: Sigmoidovaginal fistulas are the most prevalent variety of cologenital fistula caused by sigmoid diverticulitis. The diagnosis should be considered in a patient > 50 years old who complains of a foul vaginal discharge and has a history of total hysterectomy. Its presence is best demonstrated by vaginogram. Surgical therapy is advised, the extent of which will rest on the surgeon's judgment of the severity of the inflammatory process found at exploration.     

Prevalence of acute pulmonary embolism in central and subsegmental pulmonary arteries and relation to probability interpretation of ventilation/perfusion lung scans

PURPOSE: The purpose of this investigation is to determine the prevalence of acute pulmonary embolism (PE) limited to subsegmental pulmonary arteries. BACKGROUND: Contrast-enhanced helical (spiral) and electron-beam CT, in the hands of experienced radiologists who are skillful with this modality, are sensitive for the detection of acute PE in central pulmonary arteries, but have a low sensitivity for the detection of PE limited to subsegmental pulmonary arteries. The potential for CT to diagnose PE, therefore, is partially dependent on the prevalence of PE limited to subsegmental pulmonary arteries. METHODS: Data are from the Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED). The largest pulmonary arteries that showed PE, as interpreted by the PIOPED angiographic readers, were identified in 375 patients in PIOPED with angiographically diagnosed PE. RESULTS: Among all patients with PE, 6% (95% confidence interval [CI], 4 to 9%) had PE limited to subsegmental branches of the pulmonary artery. Patients with high-probability ventilation/ perfusion (V/Q) scans had PE limited to subsegmental branches in only 1% (95% CI, 0 to 4%). Among patients with low-probability V/Q lung scans, 17% (95% CI, 8 to 29%) had PE limited to the subsegmental branches. Patients with low-probability V/Q scans and no prior cardiopulmonary disease had PE limited to the subsegmental pulmonary arteries in 30% (95% CI, 13 to 53%), whereas patients with low-probability V/Q scans who had prior cardiopulmonary disease had PE limited to subsegmental pulmonary arteries in 8% (95% CI, 2 to 22%) (p < 0.05). CONCLUSION: Based on data from all patients with PE in PIOPED, the prevalence of PE limited to subsegmental pulmonary arteries is low, 6%. PE limited to subsegmental pulmonary arteries was most prevalent among patients with low-probability V/Q scans, particularly if they had no prior cardiopulmonary disease.