Prone positioning improves distribution of pulmonary perfusion: noninvasive magnetic resonance imaging study in healthy humans

The purpose of this study was to evaluate the effects of prone positioning on pulmonary perfusion using flow-sensitive alternating inversion recovery (FAIR), a noninvasive magnetic resonance imaging technique that requires no contrast medium. Seven healthy volunteers were studied in the supine and prone positions under three respiratory conditions: normal breathing of room air, unassisted breathing of 45% O₂, and controlled mechanical ventilation (CMV) with positive end-expiratory pressure. Signal intensities (SIs) were obtained from ventral, middle, and dorsal regions on sagittal lung images and dependent/nondependent SI ratios were calculated to evaluate pulmonary perfusion distribution. In the supine position, SIs increased significantly from the ventral to dorsal region under all three respiratory conditions and prone positioning inverted the perfusion distribution under all conditions. Right lung SI ratios were 2.34 ± 0.29, 2.74 ± 0.66, and 2.42 ± 0.73 in the supine position and 1.68 ± 0.48, 1.78 ± 0.36, and 1.92 ± 0.21 in prone for room air, 45% O₂, and CMV, respectively. The difference between supine and prone positions was statistically significant. The left lung showed a similar pattern and the difference was significant only under CMV. No difference was observed between the different respiratory conditions in both lungs. This study demonstrated that the distribution of pulmonary perfusion was more uniform in prone than in the supine position.     

Cerebral blood flow and vasodilatory capacity in anemia secondary to chronic renal failure

BACKGROUND: Our previous study reported that cerebral oxygen extraction fraction (OEF) increased in hemodialysis patients with anemia. The increased OEF suggests that the cerebral vasodilatory capacity might be impaired in these patients. To clarify this issue, we measured the CO2 response in patients with anemia secondary to chronic renal failure (CRF) using positron emission tomography (PET). METHODS: Ten anemic patients with CRF (6 females and 4 males) and 6 age-matched normal controls were studied. The underlying diseases of CRF were glomerulonephritis in 8 patients, systemic lupus erythematosus (SLE) in one patient, and hypertension in one patient; in this cohort, 5 patients were on hemodialysis treatment and the remaining 5 patients were in a pre-hemodialysis state. The cerebral blood flow (CBF) was measured by the O-15 H2O bolus injection method with each patient in a resting state and during 5% CO2 inhalation. The CO2 response was estimated as the percentage change of CBF per 1 mm Hg change of PaCO2. RESULTS: The CO2 response was significantly attenuated in anemic patients with CRF in comparison to the normal controls, and it inversely correlated with the severity of anemia. There was no significant difference in the CO2 response between the hemodialysis and pre-hemodialysis patients. The CO2 response significantly correlated with CBF and the cerebral metabolic rate for oxygen (CMRO2) at rest, however, it did not correlate with OEF and cerebral blood volume (CBV). CONCLUSIONS: The present study revealed the existence of a reduced cerebral vasodilatory capacity in anemic patients with CRF, suggesting that chronic hypoxic brain damage might play a role in the impaired cerebrovascular response to CO2.     

Management of pancreatic mass accompanying chronic pancreatitis

We report two patients with focal, chronic pancreatitis that was diagnosed by dynamic computed tomography (CT) combined with intraoperative biopsy. In case 1, serum carbohydrate antigen (CA) 19-9 level rose to 160 U/ml. Abdominal ultrasonography, CT, and magnetic resonance imaging demonstrated a mass, of 4.5 cm in diameter, in the pancreatic head. On dynamic CT, the mass was enhanced similarly to the normal pancreatic parenchyma. In case 2, dynamic CT demonstrated a mass, of 3.0 cm in diameter, in the pancreatic head, which was enhanced similarly to the normal pancreatic parenchyma. From such characteristics of enhancement, both masses were suspected to be chronic pancreatitis rather than cancer, and the diagnosis was confirmed by intraoperative biopsy. Three years in case 1 and 2 years in case 2 have passed since their operations, and the size of each mass has not changed. With the use of dynamic CT combined with intraoperative biopsy, focal chronic pancreatitis could be diagnosed more accurately, and this may lead to a reduction in unnecessary pancreatic resection. Received: November 16, 2001 / Accepted: February 8, 2002     

Congenital absence of lumbosacral articular facet joint associated with conjoined nerve root: a case report

We report a rare case of congenital absence of the L5-S1 facet joint, which was associated with a conjoined nerve root. Combination of these two anomalies has been quite rarely reported in the literature. A 39-year-old man presented with acute low back pain and right leg radiating pain. Muscle weakness and sensory disturbance of the right leg were also apparent in the region innervated by L5 and S1 nerve roots. Preoperative multidetector three-dimensional computed tomography (3D-CT) showed complete absence of the right S1 superior articular process. Magnetic resonance (MR) images showed lumbar disc herniation at right L5-S1 level that migrated cranially. Intraoperative findings revealed that the right L5 nerve root and S1 nerve root were conjoined, and the conjoined nerve root was compressed by L5-S1 disc herniation, which led to impairment of the conjoined nerve root by a single-level lumbar disc herniation. After removal of the disc herniation, his right leg pain immediately subsided, however muscle weakness and sensory disturbance persisted. Surgeons should be aware of this nerve root anomaly when examining a patient who shows an unusual clinical presentation and/or congenital osseous anomaly.     

Treatment of metastatic bone lesions in the upper extremity: indications for surgery

Pathological fractures caused by metastatic malignant disease have been the subject of increasing interest in recent years. This article describes our experience with the treatment of metastatic bone disease of the upper extremity and our attempt to clarify the indications for different surgical procedures. Of 53 patients with metastatic lesions to the upper extremity, 20 who had been surgically treated were analyzed retrospectively. These comprised 13 men and 7 women with a mean patient age of 62 years. The most common primary tumors to metastasize were lung and liver, with the humerus involved in 12 cases and the scapula and forearm in 4 cases each. Four patients with scapula and forearm involvement underwent tumor resection due to uncontrollable tumor size, while 3 were successfully treated by selective arterial embolization. Three metastases to the humeral head were reconstructed with endoprosthesis, but functional restriction was noted. Five cases with metastases to the humeral shaft were treated with tumor curettage, internal fixation using intramedullary nailing, adjuvant cryosurgery, and cementing. This achieved good results for pain relief and functional restoration with minimal complications. Two metastases to the humeral condyle were unable to be stabilized with plate and locking screws. Metastatic lesions to the scapula and forearm are commonly treated nonsurgically, but some patients with uncontrollable tumor mass require surgical resection. Endoprosthetic replacement is recommended if the lesion involves the humeral head or condyle. Most patients with the humeral shaft lesion are likely to benefit from tumor curettage, intramedullary nailing with locking screw, and cementing.     

A decrease of cell proliferation by hypothermia in the hippocampus of the neonatal rat

Hypothermia is a potential therapy for cerebral hypoxic ischemic injury of not only adults but also neonates. However, the side effects of hypothermia in the developing brain, where a massive amount of neurogenesis occurs, remain unclear. We investigated the proliferation of neural progenitor cells by systemic application of the thymidine analog 5-bromodeoxyuridine (BrdU) in neonatal rats in a severe hypothermic environment. The rat pups were divided into two groups, a hypothermia group (30 degrees C: n=10) and a normothermia group (37 degrees C: n=10). After the pups were placed for 21 h in each environment, 100 mg/kg/day of BrdU was injected intraperitoneally to label dividing cells, and then the pups were sacrificed at 24 h. We examined the number of BrdU-labeled cells in the subventricular zone of the periventricle and the subgranular zone of the dentate gyrus. In the hypothermic environment, BrdU-labeled cells significantly decreased in number in the dentate gyrus, but not in the periventricular region. Thus, the severe hypothermic environment induced a decrease of neurogenesis in the neonatal rat. These observations are noteworthy regarding clinical hypothermia therapy following cerebral hypoxic ischemic injury during the perinatal period.     

CSF leakage and anosmia in aneurysm clipping of anterior communicating artery by basal interhemispheric approach

We studied the incidence of postoperative infection related to CSF leakage and anosmia in basal interhemispheric approach (BIH). Between April, 1990 to March, 2009, 142 cases of anterior communicating (Acom) aneurysm including both unruptured and ruptured have been treated by clipping surgery using BIH. We retrospectively obtained clinical informations from medical records and video records about infectious complications, CSF leakage of cerebrospinal fluid (CSF), olfactory dysfunction and intraoperative findings of damage to the olfactory nerve. In most cases (139 patients, 97%), frontal sinus were opened at craniotomy. Of all, CSF rinorrhea occurred in 4 cases (2.8%), and meningitis in 6 cases. There was only one patient who sufferd from meningitis due to CSF rinorrhea. All that patients recovered completely without deficit. Anosmia occurred in 6 cases (4.2%), and intraoperative injuries in 4 cases (2.8%). There was only one patient in whom anosmia was consistent with nerve injury. In conclusion, BIH is an appropriate procedure for infection risk control in Acom aneurysm surgery. It is difficult to avoid olfactory dysfunction completely, even if olfactory nerves are preserved in form.     

Intramuscular hemangioma of the upper extremity in infants and children

PURPOSE: Intramuscular hemangiomas (IMHs) are benign tumors comprising just 0.8% of all hemangiomas and are extremely rare in the upper limbs. These tumors can pose diagnostic as well as therapeutic challenges for orthopaedic surgeons, especially in younger children. We reviewed cases of IMH of the upper extremity in infants and children from our institute. METHODS: Six consecutive patients underwent surgical treatment for IMH in our hospital. There were 4 girls and 2 boys. Long-standing pain and swelling were common symptoms except in a 1-year-old boy. Tumors were evaluated by radiography, computed tomography, magnetic resonance imaging, and angiography. RESULTS: After a mean follow-up of 42 months, all patients except one were free of pain and without tumor recurrence or functional impairment. Minimal symptoms remained in a 6-year-old boy who underwent biopsy only. CONCLUSION: Magnetic resonance imaging is the most useful evaluation for IMH because it not only delineates the extent of tumor but also reveals characteristic structures. For young children with IMH, wide excision is the treatment of choice to prevent local recurrence, but every patient should be treated individually after evaluating the patient's age, tumor location and invasion, and cosmetic considerations. LEVEL OF EVIDENCE: Therapeutic study-level III.     

Modification of the Bentall operation using the proximal double sewing technique without excision of leaflets

We present a report on reinforcement of the proximal anastomosis during the Bentall operation. The aortic wall was excised with a 5-mm remnant, and aortic valve leaflets were preserved. Interrupted horizontal mattress sutures (2-0 Polyestel) reinforced with pledgets were placed. The composite graft was placed at the intraannular position inside of the preserved leaflets. The aortic valve leaflets were then pasted to the sewing cuff with fibrin glue. A running suture with 4-0 monofilament was placed between the remnant of the aortic wall and the peripheral side of the sewing cuff wrapped with native aortic valve leaflets.     

Cecal volvulus in cerebral palsy: Report of a case

A rare case of cecal volvulus in cerebral palsy that was preoperatively diagnosed and surgically treated without complications is herein reported. A 45-year old man, who had been treated for cerebral palsy as a result of a neonatal cerebral hemorrhage, was admitted to our hospital because of abdominal pain and vomiting. A plain abdominal X-ray film showed evidence of a huge quantity of gas in the left abdomen. Using a gastrographin enema from the colonoscope, an obstruction of the ascending colon was revealed with tapering of the lumen. A computed tomography scan showed a grossly dilated air-distended bowel in the left abdomen and soft tissue with internal architecture containing swirling strands of soft tissue and fat attenuation. An emergency laparotomy was performed. During the laparotomy the ileocecal region, which was unfixed at the retroperitoneum, was found to be twisted counterclockwise by 360° around the mesentery with the terminal ileum, thus resulting in a diagnosis of cecal volvulus. We therefore conducted an ileocecal resection. Cecal volvulus is an uncommon form of intestinal obstruction with a high mortality rate and may present considerable difficulty in diagnosis. Although cecal volvulus is rare as a cause of intestinal obstruction, it should be included in the differential diagnosis of bowel obstruction in cerebral palsy.