Early Postoperative Examination Research Articles

Preoperative and postoperative follow-up in high-grade gliomas: Comparison of transcranial color-coded real-time sonography and computed tomography findings

Twenty patients with high-grade gliomas were prospectively studied by pre- and postoperative transcranial color-coded real-time sonography (TCCS) and CT, to determine the sensitivity of TCCS in the identification of residual tumor and tumor regrowth. Each patient was subjected to preoperative and early postoperative CT (postoperative day 1) and TCCS examinations (postoperative days 6 to 8) and subsequent CT and TCCS follow-up examinations within a time interval of 6 weeks to 3 months. In eight patients, a total of 15 biopsy specimens were intraoperatively obtained from the wall of the resection cavity. Histological findings of intraoperative biopsy specimens showed that hyperechogenic areas adjacent to the resection cavity always contained residual tumor tissue. Early postoperative TCCS identified these hyperechogenic areas in 19 of 20 patients. In 12 patients, postoperative CT revealed contrast enhancement at the resection margin, indicating residual tumor. In these patients the extension of these hyperechogenic areas on TCCS exceeded the contrast-enhancing areas on CT by a mean of 58%. In eight patients, postoperative CT displayed no contrast enhancement along the border of resection. TCCS and histological findings indicated residual tumor in seven of these eight patients. The size of the hyperechogenic lesions identified by postoperative TCCS increased in time and follow-up examinations revealed that tumor regrowth arose from these hyperechogenic areas in all patients. In four patients, tumor regrowth was identified, on average 0.7 months earlier by TCCS than by CT. From these data we conclude that the sensitivity of TCCS in detection of residual tumor and tumor regrowth seems to be superior to CT. The value of TCCS requires further clarification by comparative studies including histology and MRI.

The importance of sonography in the diagnosis of septic complications following spinal surgery.

The detection of infection after surgery on the thoracic and lumbar spine is difficult due to the anatomical circumstances. Clinical symptoms, laboratory findings, and most radiological techniques are of limited diagnostic value. Among other benefits, sonography offers the advantage of early postoperative examination, even with metal implants in the operated area. In a retrospective study, 27 patients with clinically suspicious wounds were evaluated by sonography in the postoperative follow-up; all cases were verified by puncture and/or operative revision. Eleven cases turned out to be hematomas, and 16 cases were found to be infections. Accumulations of fluid, however, could not be differentiated by the established sonomorphological criteria such as internal echo structures, septation, demarcation from the environment, and reaction of the surrounding tissue. Ultrasonically guided transcutaneous needle aspiration biopsy served to differentiate the local findings and to establish the diagnosis and therefore is required as an obligatory method of investigation.

Duplex doppler ultrasound for the detection of vascular occlusion following liver transplantation in children

Sixty-three children and adolescent patients who received 78 consecutive orthotopic liver transplants and had serial duplex ultrasound monitoring were retrospectively reviewed for episodes of occlusion of the hepatic artery or portal vein. There were 13 documented episodes of complete occlusion of the main hepatic artery or a major branch, of which nine were diagnosed by the absence of flow during duplex ultrasound examination. Four occlusions were not detected, two affected hepatic artery branches, one an accessory hepatic artery, and one the main hepatic artery. The overall sensitivity of the method was 69% and specificity 100%. Six portal vein occlusions were documented in five patients and all six were successfully diagnosed on ultrasound examination, giving a sensitivity and specificity of 100%. Three of the patients had simultaneous occlusions of both vessels. In the early post-operative period duplex Doppler ultrasound examination has proved an effective non-invasive method for the detection of vascular occlusion, but is not yet sensitive enough to replace angiography fully for the detection of hepatic artery occlusion, particularly when this occurs distal to the main hepatic artery.

Cerebral protection during aneurysm surgery with isoflurane anesthesia

A strategy for intraoperative cerebral protection is described in which intraoperative electroencephalography is used to titrate the level of inspired isoflurane given for anesthesia to obtain isoelectricity prior to temporary vessel occlusion during repair of difficult aneurysms. During temporary vessel occlusion, arterial blood pressure is maintained or increased with an inotropic or vasopressor agent. After clipping of the aneurysm, the concentration of isoflurane is reduced to allow the patient to awaken in the operating room for early postoperative neurological examination. The combination of a high concentration of isoflurane, temporary vessel occlusion, and maintenance of arterial blood pressure may be a useful protective regimen during neurovascular procedures.

Remodeling of the tibial plateau after knee replacement. CT bone densitometry.

We measured the changes of bone density by computed tomography of the proximal tibia after total knee replacement in 18 patients, 9 with arthrosis and 9 with rheumatoid arthritis. All the patients had good results after 1 and 2 years. There were no significant radiolucencies at the cement-bone interface. At the early postoperative measurements, we found abnormal mediolateral distributions of density, closely related to the preoperative tibiofemoral angle (r = -0.67). This distribution was within normal limits after 3 months in knees with preoperative valgus and after 2 years in knees with preoperative varus. The mean tibial density did not differ between patients with arthrosis and rheumatoid arthritis at the early postoperative examination, but the density in rheumatoid patients decreased by one third during the 2-year period. Although the overall change after knee replacement was loss of density, the preoperatively less loaded condyles had a slight tendency towards increasing density with time, a response that was considerable in some cases.

Postoperative sonographic follow-up of brain tumors in childhood

Postoperative neurosonography was performed in 69 babies and children after osteoclastic neurosurgery for primary cerebral tumors. Astrocytoma of the posterior fossa (26 cases) and medulloblastoma (25 cases) were frequent histological findings. Early postoperative bed-side examinations revealed reliably complications such as cerebral hemorrhage, edema or hygroma. Postoperative baseline studies were performed and reliability of sonographic criteria for tumor recurrence, such as high echogenicity and dense echotexture, were established. Regressive tissue changes under the usual postoperative cerebral radiation therapy and chemotherapy included transient increase in perifocal edema followed by tumor shrinking and cystic lesions or calcifications. Shunt dynamics were controlled by morphometrical studies of ventricular size. Long-time follow-up examinations were performed in most cases and covered periods of up to 4 years. Sensitivity of neurosonography for tumor recurrence was superior to non-contrast computed tomography; there were no false positive findings as proven by CT and magnetic resonance.

The value of early postoperative CT study after lumbar intervertebral disk surgery

The changes of the early intraspinal conditions few days after an operation of a lumbar disc herniation are little known. We, therefore, examined these operation areas by CT on a representative group of 256 patients. Besides the "common" findings, such as seroma, one must classify conditions such as haematomas, isolated bone fragments and/or residual disc tissue as "unusual" changes. The CT findings are correlated with clinical symptoms. We conducted CT and clinical follow-up studies in 91 patients several weeks later. All patients showed epidural scars of very different intensity. The comparison between early postoperative findings and the controls documents the high accuracy of the interpretation of the early postoperative states seen by CT. Therefore, it is possible to give hints for the indication for early postoperative CT examinations, for the prognosis as well as for the technique for a safe operative procedure.