Diagnostic accuracy of focused appendiceal CT in clinically equivocal cases of acute appendicitis.

PURPOSE: To determine the diagnostic accuracy of modified focused appendiceal computed tomography (CT) to exclude or confirm appendicitis in patients who presented with equivocal symptoms and signs of appendicitis. MATERIALS AND METHODS: One hundred patients (age range, 14-81 years; mean age, 30.6 years) with equivocal symptoms and signs of acute appendicitis were included in this prospective study. Patients were given 30 mL of diatrizoate meglumine and diatrizoate sodium and 60 mL of sorbitol mixed in 1 L of water orally over 1 hour. CT was performed 1.5 hours after the commencement of oral contrast material administration. The criteria used for the diagnosis of appendicitis were (a) appendix greater than 6 mm in maximum diameter, (b) no contrast material in the appendiceal lumen, and (c) inflammatory changes in the periappendiceal fat. CT results were compared with histopathologic findings at appendectomy. Patients with negative CT findings were followed up by telephone or clinically. RESULTS: Of 100 cases, 30 were positive at CT and 70 were negative. There were 28 true-positive cases; two false-positive cases, one cecal diverticulitis and one pelvic peritonitis with periappendicitis; and two false-negative cases, one perforated appendix and one mucosal and submucosal inflammation of the appendix but no transmural inflammation. Sensitivity was 93%, specificity was 97%, and accuracy was 96%. CONCLUSION: Focused appendiceal CT in which oral contrast material is used alone yields high levels of accuracy in clinically equivocal cases of acute appendicitis.

Solitary fibrous tumor of the cerebello-pontine angle.

A case is presented of solitary fibrous tumor occurring in the cerebello-pontine angle. There have been only two other reported cases of a solitary fibrous tumors in this region. Imaging studies showed the tumor to be characteristic in shape and position of an acoustic tumor. However, at surgery the tumor was found to have a "rock hard" consistency. Solitary fibrous tumor differs from acoustic schwannoma and meningioma in its histopathological features and in this case, regrowth, after incomplete excision, was extremely rapid.

Pneumocephalus after acoustic neuroma surgery.

OBJECTIVE: The study was conducted to describe the diagnosis and management of pneumocephalus after acoustic tumor resection. STUDY DESIGN: The study design was a retrospective chart review. SETTING: The study was conducted as a tertiary otologic referral to the senior authors' practices (PAF, MDA). PARTICIPANTS: Three patients operated on for acoustic tumor in St. Vincent's General Hospital and the Scottish Hospital, Sydney, Australia, were studied. INTERVENTION: Observation in both cases and surgery in a case in which tension pneumocephalus was progressive were performed. MAIN OUTCOME MEASURE: Recovery will follow either spontaneously or after intervention. RESULTS: All patients had an uneventful recovery. CONCLUSION: In most cases, spontaneous resolution occurs. However, if surgical re-exploration is indicated, it is best performed via the blind sac subtotal petrosectomy of Fisch.

Incidence of deep vein thrombosis after laparoscopic vs minilaparotomy cholecystectomy.

OBJECTIVES: To determine the frequency of deep vein thrombosis (DVT) associated with minimally invasive cholecystectomy and to determine, using minilaparotomy cholecystectomy as a control operation, the influence of the laparoscopic pneumoperitoneum on DVT formation. DESIGN: Prospective nonrandomized control trial. SETTING: Tertiary care university hospital. PATIENTS: One hundred consecutive patients intended to undergo either laparoscopic cholecystectomy (59 patients) or minilaparotomy cholecystectomy (41 patients) with either of 2 surgeons were prospectively enrolled between April 1996 and April 1997. The minilaparotomy cholecystectomy group served as controls to isolate the effect of the pneumoperitoneum. Patient details, operative details, and any thromboembolic or bleeding complications were recorded. The same thromboprophylaxis regimen was prescribed for each group; namely, preoperative and postoperative subcutaneous low-molecular-weight heparin (LMWH), graduated compression stockings, and intraoperative intermittent calf compression. INTERVENTION: Minimally invasive cholecystectomy. MAIN OUTCOME MEASURE: Frequency of DVT. Bilateral lower limb venous color duplex scanning was used to detect DVT. Scans were performed on 3 occasions: (1) preoperatively on admission to hospital, (2) on the first postoperative day, and (3) between 2 and 4 weeks postoperatively. RESULTS: Three patients in the laparoscopic group and 2 patients in the minilaparotomy group underwent conversion to conventional open cholecystectomy. There were no significant differences between patients in the 2 groups for age, sex, body mass index, preoperative white blood cell count, platelet count, prothrombin time, or activated partial thromboplastin time. There were no significant differences between the 2 groups for elective vs emergency operations, public hospital vs private hospital admissions, or consultant vs resident surgeon. Macroscopic gallbladder pathology grades for both groups were not significantly different, and there was no significant difference in the duration of postoperative hospital stay. Operative cholangiography was performed in a significantly larger proportion of laparoscopic cases (86% vs 66% in the minilaparotomy group; chi(2) test, P=.002), and the duration of anesthesia was significantly longer for the laparoscopic operation (118 minutes vs 98 minutes; t test, P=.05). Ninety-seven patients received preoperative LMWH and all patients received graduated compression stockings, intraoperative intermittent calf compression, and postoperative LMWH. Two of the 100 patients had postoperative DVT, 1 after laparoscopic cholecystectomy and 1 after minilaparotomy cholecystectomy. Both DVTs were detected by duplex examination on the first postoperative day. The DVT found after laparoscopic cholecystectomy was in 1 of the 3 patients who did not receive preoperative LMWH. There were no DVTs in any of the 40 patients who had an additional duplex scan between 2 and 4 weeks after operation. CONCLUSIONS: Despite the theoretical risk of thromboembolic disease due to use of the laparoscopic pneumoperitoneum, the frequency of DVT after either laparoscopic cholecystectomy or minilaparotomy cholecystectomy is low if adequate thromboprophylaxis is provided.

The cerebellopontine angle: does the translabyrinthine approach give adequate access?

A long-standing but unfounded criticism of the translabyrinthine approach is the misperception that this approach does not give adequate access to the cerebellopontine angle. Because of what is perceived as limited visualization and operating space within the cerebellopontine angle, some surgeons still believe that the translabyrinthine approach is inappropriate for large acoustic tumors. In this study, the surgical access to the cerebellopontine angle by virtue of the translabyrinthine approach is measured and analyzed. The parameters are compared with those measured for the retrosigmoid approach. This series objectively confirms that the translabyrinthine approach offers the neurotologic surgeon a shorter operative depth to the tumor, via a similar-sized craniotomy. This permits superior visualization by virtue of a wider angle of surgical access. Such access is achieved with the merit of minimal cerebellar retraction.

Knowledge-based method for segmentation and analysis of lung boundaries in chest X-ray images.

We present a knowledge-based approach to segmentation and analysis of the lung boundaries in chest X-rays. Image edges are matched to an anatomical model of the lung boundary using parametric features. A modular system architecture was developed which incorporates the model, image processing routines, an inference engine and a blackboard. Edges associated with the lung boundary are automatically identified and abnormal features are reported. In preliminary testing on 14 images for a set of 18 detectable abnormalities, the system showed a sensitivity of 88% and a specificity of 95% when compared with assessment by an experienced radiologist.

Jejunojejunal intussusception secondary to leiomyoma.

A case of jejunojejunal intussusception in a 59 year old male secondary to a leiomyoma is reported. The patient presented with abdominal pain and vomiting. He was admitted with a diagnosis of gastroenteritis. Antegrade barium study showed a jejunojejunal intussusception with a soft tissue mass as the lead point. Computed tomography scan demonstrated the soft tissue mass to have properties suggestive of a leiomyoma. The diagnosis was confirmed on examination of the excised specimen.

Biliary dilatation in asymptomatic AIDS patients.

Cytomegalovirus (CMV) is a recognized cause of biliary abnormalities in acquired immune deficiency syndrome (AIDS) patients. In a prospective trial, two of 25 (8%) of AIDS patients on treatment for CMV related infections without biliary symptoms were found to have biliary dilatation on ultrasound. The study confirms previous findings of the poor correlation of sonographic findings with clinical status and biochemical profiles, and demonstrates that biliary tree dilatation in this group of patients may not per se warrant further invasive investigation.

Facial neuroma of the cerebellopontine angle and the internal auditory canal.

Four cases of facial neuroma confined to the cerebellopontine angle and internal auditory canal are presented. Prior to surgery, three of these were diagnosed as an acoustic tumor. At operation the true diagnosis of facial neuroma was made. The operative procedure was recorded on film and videotape. The magnetic resonance imaging (MRI) and computed tomography (CT) scans were reviewed retrospectively. In the first three cases the tumor was not centered on the axis of the internal auditory canal (IAC), as would be typical of an acoustic neuroma, but instead occupied a position eccentric to this axis. In one case, this eccentricity was marked. A similar appearance in the fourth case enabled the true diagnosis of facial neuroma to be made before surgery. The postoperative behavior of the tumors was unpredictable. The patient with the largest tumor, which was debulked at operation, did not develop a facial palsy. However, a patient with a small tumor which was not biopsied, developed a delayed but complete paralysis from which she subsequently recovered. This small series suggests that it may be possible, by use of the appropriate imaging technique, to diagnose, preoperatively, a cerebellopontine angle facial neuroma which is otherwise indistinguishable from an acoustic neuroma.

Late presentation and development of nephrocalcinosis in primary hyperoxaluria.

A case of primary hyperoxaluria type 1 with complete deficiency of alanine:glyoxalate aminotransferase that first manifested at the age of 59 with irreversible acute on chronic renal failure is reported. Nephrocalcinosis, initially absent, developed rapidly after renal failure evolved. The possible role of hypovolaemia and contrast nephrotoxicity in precipitating the clinical onset is discussed. Primary hyperoxaluria should be considered in patients of any age presenting with unexplained renal failure, and appropriate systemic pathology of oxalosis.

Venous drainage of free flaps following radical neck dissection.

Large tissue defects may occur following head and neck surgery. When combined with ipsilateral radical neck dissection the venous drainage of a free flap used to cover the defect may be compromised. Twelve patients having radical neck dissections underwent on-table venography to study the pattern of venous drainage of these flaps. The predominant drainage pattern is initially in a cephalic direction, then across the midline and finally in a caudal direction on the contralateral side of the neck. Venous drainage to the contralateral side of the neck may be a determinant of flap survival. In order to facilitate venous drainage following free flap procedures, patients should be positioned so that the contralateral internal jugular vein is not compressed. Drains should be placed caudal to the microvascular anastomoses in order to minimize interference with the cephalic direction of venous drainage. Any patient having a radical neck dissection requiring a central venous catheter should have it placed ipsilateral to the neck dissection. Thrombosis around a contralaterally placed cannula may significantly increase head and neck venous pressure.

Meningioma of the posterior skull base.

Combined intratemporal and cerebellopontine angle meningiomas are rejatively rare. There are unsolved problems with the stability of the skull and spine and the lower cranial nerves and there is a marked tendency for the tumor to involve the spinal cord. This article reports on five cases of combined intratemporal and cerebellopontine angle meningiomas.

Isolated congenital round window absence.

An adult with unilateral round window atresia is presented. With care, CT scanning may be used to demonstrate round window occlusion. Cochlear fenestration resulted in only a modest hearing improvement. Previously reported cases are reviewed.