MR digital subtraction angiography of cerebral arteriovenous malformations

BACKGROUND AND PURPOSE: Although phase-contrast MR angiography provides some information regarding hemodynamics of cerebral arteriovenous malformations (AVMs), most conventional MR angiographic techniques have not been helpful in this respect. We attempted to determine the value of MR digital subtraction angiography (DSA) in assessing AVM hemodynamics. METHODS: We developed an MR DSA technique by combining rapid thick-section T1-weighted imaging with a bolus injection of contrast material. The temporal resolution was 0.56 to 0.61 seconds per scan. MR DSA images obtained from 14 patients with AVMs were reviewed. Anatomic depiction of each component of the AVM was rated using a four-point grading scale (excellent = 3, good = 2, fair = 1, poor = 0) to compare conventional vs MR angiograms. RESULTS: We were able to obtain serial images in which passage of contrast material was evident within the AVM, although the sequence we used allowed images to be obtained in only one projection. The average score for feeders, nidi, and drainers was 1.6, 2.4, and 2.3, respectively, with an overall average of 2.1. CONCLUSION: The spatial resolution of our technique may fall below the level needed for identification of small vascular components of an AVM. Additionally, the limited slab may restrict application of the technique to assessment of large or very small AVMs. MR DSA, however, can show the hemodynamics of AVMs and may serve as a supplement to conventional MR imaging in the diagnosis of cerebral AVMs.     

Pre- and postcontrast FLAIR MR imaging in the diagnosis of intracranial meningeal pathology

PURPOSE: Few reports address the use of fluid-attenuated inversion-recovery (FLAIR) images of the brain in the diagnosis of extraaxial lesions. Our purpose was to assess the value of FLAIR images, including postcontrast ones, in the diagnosis of intracranial meningeal diseases. METHODS: We reviewed precontrast (n=24) and postcontrast (n=20) FLAIR images obtained from 25 patients with infectious meningitis (n=13), carcinomatous meningitis or dissemination of primary brain tumor (n=7), dural metastasis (n=3), and others (n=2) in comparison with fast spin-echo T2-weighted and postcontrast T1-weighted images. RESULTS: In lesion detectability, precontrast FLAIR images were significantly superior to fast spin-echo T2-weighted images but inferior to postcontrast T1-weighted images. There was no significant difference between postcontrast T1-weighted and FLAIR images. CONCLUSION: Precontrast FLAIR images can substitute for conventional fast spin-echo T2-weighted images. Postcontrast FLAIR images have diagnostic potential equivalent to conventional postcontrast T1-weighted images.     

A Palmar Fracture-Dislocation of the Proximal Interphalangeal Joint of the Middle Finger Caused by Bowling: A Case Report

During bowling, a twenty year old man could not pull out his middle finger from the ball in release and injured his finger. X-ray revealed a palmar fracture- dislocation of the PIP joint. We manipulated the PIP joint, but a gap remained at the fracture site on the X-ray after reduction. Surgical treatment was performed with a screw. Postoperatively, the middle finger was fixed with a splint for two weeks, and then active range of motion exercises were started. One year after the operation, the fracture had healed with a congruous joint surface, and the patient had full range of motion in the middle finger with no difficulties in activities of daily living. The etiology of a palmar fracture-dislocation of the PIP joint is still controversial, but we suggested the mechanism of the fracture-dislocation was caused by a shearing force to the middle phalangeal base from a dorsal direction. The main cause of the current injury was the poor fit between the middle finger and the hole of the bowling ball. Bowling is a popular and safe sport, but we should be aware of unexpected hand injuries related to bowling which may occur, especially in players at a recreational level.

Key points

• We presented a palmar fracture-dislocation of the PIP joint in a middle finger that occured while bowling.
• We discussed the mechanism and suggested the main cause of the injury was the poor fit between the middle finger and the hole of the bowling ball.
• We advised that while bowling is recognized as a safe sport, due to its popularity we should be aware of unexpected hand injuries which may occur, especially in players at a recreational level.

Key words: Palmal fracture-dislocation, PIP joint, bowling, sports     

Long-term outcome of hand-assisted laparoscopic radical nephrectomy for localized stage T1/T2 renal-cell carcinoma

PURPOSE: To evaluate the efficacy of hand-assisted laparoscopic radical nephrectomy (HALRN) in patients with localized stage T(1)/T(2) renal-cell carcinoma, we analyzed the clinical results of our patients treated in this way. PATIENTS AND METHODS: From March 1999 to March 2003, a total of 96 patients aged 28 to 86 years (mean 61 years) with clinical stage T(1)/T(2)N(0)M(0), pathologically confirmed renal-cell carcinoma underwent HALRN. The outcomes were compared with those of open radical nephrectomy, which was performed in 86 patients from November 1991 to February 1999 in our institution. Kaplan-Meier analysis was used to analyze survival. RESULTS: Ten patients (10.4%) had perioperative complications. During a mean follow-up of 25 months (range 6-54 months), no patients died of the cancer, although three patients had metastatic disease. The 4-year disease- free and overall survival rates were 88% and 100%, respectively. Seventy-eight patients who underwent open radical nephrectomy were followed for 38 to 156 months (median 86 months). Seventy-three survived without any recurrent disease, five survived with metastasis, and no patient died of metastatic disease. The 4-year disease-free and overall survival rates were 93% and 100%, respectively. CONCLUSIONS: Hand-assisted laparoscopic surgical management of T(1)/T(2) renal-cell carcinoma is feasible and safe. At our institution, HALRN confers long-term oncologic effectiveness equivalent to that of open radical nephrectomy.     

Cytomegalovirus infection following renal transplantation in patients administered low-dose rituximab induction therapy

Anti-CD20 antibody (rituximab) is recently being used as a B cell-depleting agent in renal transplantation (RTx). However, the incidence of infectious complications associated with rituximab therapy remains uncertain. We evaluated the incidence of cytomegalovirus (CMV) infection associated with rituximab therapy in RTx. A total of 83 patients were enrolled. The immunosuppressive regimen consisted of tacrolimus or cyclosporin, mycophenolate mofetil, methylprednisolone and basiliximab. In 54 patients, only one dose of rituximab (200 or 500 mg/kg body weight) was given before RTx. A total of 25 of 43 (58.1%) recipients who were CMV seropositive prior to RTx and who received rituximab induction therapy developed CMV infection, compared to 18 of 24 (75%) CMV seropositive recipients who did not receive rituximab therapy ( P  = 0.1676). A total of 8 of 11 patients who were CMV seronegative prior to RTx and who received rituximab developed CMV infection. However, CMV seroconversion was seen in all 8 of these infected patients. Low-dose rituximab induction therapy in renal transplant recipients appears to have no influence on the incidence of CMV infection and CMV seroconversion. However, we have to consider anti-CMV prophylaxis therapy, because of high incidents of CMV infection, especially for CMV seronegative recipients who received rituximab.     

Radiofrequency ablation for renal tumors: Our experience

Objectives:   To report our results of percutaneous radiofrequency ablation (RFA) for renal tumors and to assess predictors of therapeutic efficacy.
Methods:   Forty patients (median age 73 years) with renal tumors were treated with RFA under local or epidural anesthesia. All of them had high surgical risk or refused radical surgery. Tumors were punctured percutaneously using the Radionics Cool-tip RF System under computed tomography or ultrasonographic guidance. Median tumor diameter was 24 mm. After RFA, contrast-enhanced computed tomography or magnetic resonance imaging was performed within 1 month. Complete response (CR) was defined as no enhancement inside the tumor. Factors related to the outcome and to renal function were assessed.
Results:   Median follow up was 16 months. CR was observed in 34 cases (85.0%). A significant difference in CR rate was observed between tumors ≤30 mm and those >30 mm. Outcomes tended to be better for tumors in the mid to lower kidney, and those away from the renal hilum. Recurrence was observed in one case (2.9%), but a CR was obtained again by additional RFA. Out of a total of 77 RFA procedures, complications occurred in only three cases (3.9%), and conservative treatment was possible in all cases. Serum creatinine levels 3 months after RFA did not differ from those before RFA.
Conclusions:   Percutaneous RFA is a safe and effective treatment for small renal tumors in patients with high surgical risk or who refuse radical surgery.     

The dynamics and clinical significance of alpha 2 plasmin inhibitor-plasmin complex and thrombin-antithrombin complex in postoperative pleural effusion following a pulmonary lobectomy

Purpose  The overall incidence of postoperative alveolar air leakage (AAL) remains high; however, the mechanism regarding how to adequately heal such postoperative AAL remains to be elucidated. The aim of this study was to determine any correlations between the activity of the fibrinolytic and coagulation system in the postoperative pleural effusion and appearance or disappearance of postoperative AAL. Methods  This study prospectively investigated 25 patients who underwent a pulmonary lobectomy from July 2005 to March 2006. Pleural effusion was collected through the chest tube. Alpha 2 plasmin inhibitor-plasmin complex (PIC), as a fibrinolytic marker, and thrombin-antithrombin complex (TAT), as a coagulation marker, were measured. Results  The activity of the coagulation system was higher than that of the fibrinolytic system. The concentration of TAT tended to increase (3rd vs 4th postoperative day [POD], P = 0.0907). The mean time of appearance and disappearance of postoperative AAL was 1.4 days and 3.2 days, respectively. The patients with postoperative AAL had a TAT level significantly below the average on the 3rd POD in comparison to the patients without postoperative AAL (P = 0.0163). Moreover, the concentration of TAT in patients with postoperative AAL was significantly lower than that in patients without postoperative AAL (1824.0 ± 137.3 ng/ml vs 3444.0 ± 287.6 ng/ml, P = 0.0113) on the 3rd POD. On the 4th POD, the concentration of TAT was almost same and there was no significance (P = 0.6759). Conclusions  This study demonstrated for the first time the course of the fibrinolytic and coagulation activity in the pleural effusion after a pulmonary lobectomy, and showed that the delayed activity of the coagulation system is associated with the appearance of the postoperative AAL.     

The frontal cortex is activated during learning of endoscopic procedures

Background

To date, several training and evaluation systems for endoscopic surgery have been developed, such as virtual-reality simulators and box trainers. However, despite current advances in these objective assessments, no functional brain studies during learning of endoscopic surgical skills have been carried out. In the present study, we investigated cortical activation using near-infrared spectroscopy (NIRS) during endoscopic surgical tasks.

Study design

A total of 21 right-handed subjects, comprising 4 surgical experts, 4 trainees, and 13 novices, participated in the study. Suturing and knot-tying tasks were performed in a box trainer. Cortical activation was assessed in all subjects by task-related changes in hemoglobin (Hb) oxygenation using NIRS.

Results

In surgical experts and novices with no experience of endoscopic surgical training, we found no changes in oxy-Hb, deoxy-Hb or total-Hb levels in any of the frontal channels. In surgical trainees and one novice with experience of endoscopic surgical training, we found significant increases in oxy-Hb and total-Hb levels in most of the frontal channels. There were significant differences in oxy-Hb and total-Hb levels in CH-19 between surgical experts and trainees (p = 0.02 for both), and between surgical trainees and novices with no experience of endoscopic surgical training (p = 0.008 for both). Furthermore, additional training increased oxy-Hb levels in the frontal cortex of novices with no experience of endoscopic surgical training but had no such effect on surgical experts.

Conclusions

The present data suggest that NIRS is a feasible tool for assessing brain activation during endoscopic surgical tasks, and may have a large impact on the future development of teaching, training, and assessment methods for endoscopic surgical skills.     

Optimal temperature for the management of severe traumatic brain injury: effect of hypothermia on intracranial pressure,systemic and intracranial hemodynamics,and metabolism

OBJECTIVE: We studied the effect of hypothermia on intracranial pressure, systemic and intracranial hemodynamics, and metabolism in patients with severe traumatic brain injury to clarify the optimal temperature for hypothermia, with a view toward establishing the proper management techniques for such patients. METHODS: The study was performed in 31 patients with severe head injury (Glasgow Coma Scale score as high as 5). All patients were sedated, paralyzed, ventilated, and cooled to 33 degrees C. Brain temperature, core temperature, intracranial pressure, cerebral perfusion pressure, jugular venous oxygen saturation, mixed venous oxygen saturation, cardiac output, oxygen delivery, oxygen consumption, and resting energy expenditure were monitored continuously. RESULTS: Intracranial pressure decreased significantly at brain temperatures below 37 degrees C and decreased more sharply at temperatures 35 to 36 degrees C, but no differences were observed at temperatures below 35 degrees C. Cerebral perfusion pressure peaked at 35.0 to 35.9 degrees C and decreased with further decreases in temperature. Jugular venous oxygen saturation and mixed venous oxygen saturation remained in the normal range during hypothermia. Resting energy expenditure and cardiac output decreased progressively with hypothermia. Oxygen delivery and oxygen consumption decreased to abnormally low levels at rectal temperatures below 35 degrees C, and the correlation between them became less significant at less than 35 degrees C than that when temperatures were 35 degrees C or higher. Brain temperature was consistently higher than rectal temperature by 0.5 +/- 0.3 degrees C. CONCLUSION: These results suggest that, after traumatic brain injury, decreasing body temperature to 35 to 35.5 degrees C can reduce intracranial hypertension while maintaining sufficient cerebral perfusion pressure without cardiac dysfunction or oxygen debt. Thus, 35 to 35.5 degrees C seems to be the optimal temperature at which to treat patients with severe traumatic brain injury.     

Use of candesartan cilexetil decreases proteinuria in renal transplant patients with chronic allograft dysfunction

BACKGROUND: Posttransplant proteinuria and hypertension are difficult to treat after renal transplantation. Therefore, we examined whether candesartan cilexetil is effective in reducing urinary protein excretion or in controlling hypertension in patients with renal allograft dysfunction. METHODS: Sixty-two renal transplant recipients with proteinuria were enrolled in this study. They underwent kidney transplantation under cyclosporine or tacrolimus immunosuppression between February 1983 and December 1998. Causes of proteinuria were chronic rejection in 28, glomerulonephritis in 16, cyclosporine or tacrolimus nephrotoxicity in 9, and unknown in 9 recipients. The dose of candesartan cilexetil ranged from 4 to 12 mg/day. Eleven patients with proteinuria who had not been treated with candesartan cilexetil constituted a matched control population. RESULTS: Hypertension was well controlled by administration of candesartan cilexetil. Both systolic blood pressure and diastolic blood pressure significantly decreased from 141.7+/-14.8 mm Hg to 118.7+/-11.9 mm Hg and 121.2+/-11.6 mm Hg, and from 89.0+/-13.0 mm Hg to 72.0+/-10.4 mm Hg and 74.9+/-9.4 mm Hg, at 2 months and 1 year after administration, respectively. Urinary protein excretion was reduced from 0.93+/-1.2 g/day to 0.34+/-0.7 g/day and 0.43+/-1.2 g/day at 2 months and 1 year after administration, respectively. The levels of creatinine clearance were 55.7+/-28.9 mL/min before treatment, 50.9+/-24.8 mL/min at 2 months, and 52.6+/-24.8 mL/min at 1 year after treatment, respectively. There was no clinically significant difference between them. Regarding the calcineurin inhibitor levels, there was no significant difference between the levels before and 1 year after treatment. There was a significant difference in all examinations (systolic blood pressure, diastolic blood pressure, proteinuria, and renal function) between the patients with and without candesartan at 1 year after treatment. No significant adverse effects occurred. CONCLUSIONS: Candesartan cilexetil can effectively control hypertension and proteinuria without deterioration in renal allograft function. These data suggest that treatment with candesartan cilexetil may be useful for maintaining long-term renal allograft function.