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[Intraarterial calcium stimulation (ASVS) for pancreatic insulinoma: comparison of preoperative localization procedures].

PURPOSE: Evaluation of clinical relevance of the arterial stimulation procedure with venous sampling (ASVS) in the preoperative localization of insulinoma. METHODS: Thirteen patients with endogenous hyperinsulinism underwent preoperative transabdominal ultrasound (US), helical CT (CT), MRI, endoscopic ultrasound (EUS), and angiography (DSA) in conjunction with the ASVS-test for the detection of insulinoma. The results were compared with intraoperative findings, intraoperative ultrasound (IOUS) and histology. RESULTS: Sensitivity was as follows: US 8%, MRI 27%, CT 46%, EUS 50%,DSA 69%,and ASVS 92%. Intraoperative palpation and IOUS yielded a sensitivity of 77%. In 3 patients the tumors were neither palpable nor detectable by IOUS, the mode of resection was based on preoperative diagnostics. The ASVS procedure as a functional test was superior to all other modalities for the preoperative tumor detection. CONCLUSION: The ASVS was the most sensitive diagnostic modality. It should especially be considered in terms of health economical aspects when CT or MRI do not yield conclusive results.

Adolescent↗

The use of hybrid stereolithographic models for the planning of complex craniofacial procedures.

Preoperative planning of orthognathic surgery is usually based on plaster cast models. Those are integrated in an articulator, simulating the movement of the jaws. We present a new procedure to combine the individual jaw anatomy by stereolithographical models with dental plaster casts, which are more accurately reproducing dental and bony anatomy. For image fusion the patient and the individual plaster casts are scanned by computed tomography, the occlusal planes being covered by a splint with radioopaque makers. After threshold segmentation of both, the plaster cast and the patients skull images are fused. The plaster cast volume is then subtracted from the patients upper and lower jaw, thus sparing out the place for later fusion of stereolithographic model and plaster cast.

Computer Graphics↗

Incidence of phlogistic complications in infantile posterior fossa surgery according to the different preoperative diagnostic procedures.

Sixty seven infantile patients developing postoperative phlogistic complications as a consequence of posterior fossa surgery (i.e.: neoplasms, arachnoid cysts, A-V malformations) are herein studied. They have been subdivided in 2 groups in accordance to the different preoperative diagnostic procedures they underwent. In the first series 41 cases of posterior fossa anomalies have been diagnosed by means of air contrast ventriculography with or without cerebral angiography; in the other one the 26 patients were submitted to C.A.T. with or without angiography. In the first group the incidence rate of phlogistic complications was 31.7%, in the second one 3.8%. According to the authors this considerable difference is due to the diagnostic procedures employed. Contraindications to air contrast ventriculography and advantages of CT scan are widely discussed and emphasized.

Arachnoid↗

The importance of preoperative localisation procedures in organic hyperinsulinism--experience in 67 patients.

BACKGROUND: Preoperative localisation of insulinomas has been regarded unnecessary, given the significantly higher detection rates of intraoperative ultrasonography and bidigital palpation. These are mandatory before endoscopic surgery. METHODS: 67 patients operated on for organic hyperinsulinism were retrospectively analysed regarding tumour localisation within the pancreas, tumour size, histological findings, sensitivities of preoperative imaging methods, and surgical techniques. RESULTS: 59 patients (88%) had solitary insulinomas, four patients (6%) multiple insulinomas and four adult patients (6%) nesidioblastosis. Well-differentiated neuroendocrine tumours with benign behaviour (including four patients with nesidioblastosis) were diagnosed in 53 patients (79%), tumours with uncertain behaviour in nine patients (13%) and well-differentiated neuroendocrine carcinomas in five (8%). Tumours were evenly distributed throughout the pancreas. Endoscopic ultrasound localised tumours in 15 out of 21 patients (71%), conventional computed tomography (CT) in 7 out of 21 (33%), single-slice helical CT in 7 out of 12 (58%), multidetector CT in 5 out of 5 (100%), magnetic resonance imaging in 11 out of 13 (85%) and angiography in 15 out of 23 (65%). Various combinations of available methods achieved a sensitivity of 88% (49 patients true positive, 4 true negative, 7 false negative). Of 59 patients, solitary insulinomas were enucleated in 47 (80%), 11 patients underwent conventional open resection and one patient endoscopic distal pancreatic resection. Patients with nesidioblastosis or multiple tumours underwent pancreatic resections alone or in combination with enucleations. CONCLUSION: After biochemical diagnosis of organic hyperinsulinism, preoperative localisation is necessary for planning endoscopic pancreatic surgery, because of the possibility of multiple insulinomas, malignancy or nesidioblastosis in adults.

Carcinoma, Neuroendocrine↗

Acute colonic obstruction: clinical aspects and cost-effectiveness of preoperative and palliative treatment with self-expanding metallic stents--a preliminary report.

PURPOSE: Evaluation of clinical aspects and cost-effectiveness of use of self-expanding metallic stents in the treatment of acute colonic obstruction as either a preoperative procedure or palliation. MATERIALS AND METHODS: Thirteen consecutive patients, aged 49-83 years (mean, 67 years), with clinical and radiologic signs of colonic obstruction were treated as a preoperative procedure in 10 patients and as a palliative treatment in three. A total of 16 self-expanding metallic stents (diameter, 16 mm; length fully expanded, 56 mm) were implanted with combined fluoroscopic and endoscopic guidance. The costs (hospitalization, intensive care unit, stent placement, and surgery) were compared with costs for 13 surgically treated patients at the same hospital. RESULTS: Stent placement was successful in 12 of the 13 patients; all recovered from mechanical obstruction, and single-stage surgery was possible in eight of nine patients treated preoperatively. One very narrow stenosis could not be passed. Dysfunction occurred in two long stenoses after 5 days with reocclusion 2 and 6 weeks, respectively, after stent placement. A cost reduction of 19.7% was observed as a result of shorter hospitalization and a lower complication rate. In patients with colon cancer in the preoperative treatment group, the cost reduction increased to 28.8%. CONCLUSION: Metallic stent placement in patients with acute colonic obstruction was a minimally invasive and cost-effective preoperative procedure that allowed single-stage surgery in most cases. Stent placement for palliation should be limited to patient with special indications.

Acute Disease↗

Parathyroid imaging: its current status and future role.

The management of autonomous (primary or tertiary) hyperparathyroidism is controversial for two important reasons: (1) Diagnosis of primary or tertiary hyperparathyroidism (as distinct from reactive or secondary hyperparathyroidism) has been revolutionized in the past 20 years as a result of routine inclusion of serum calcium concentration assays in serum multiautomated analysis, now obtained routinely for both hospitalized as well as ambulatory patients. The prevalence of primary hyperparathyroidism in the general population has appeared to rise as a consequence of this assay and the enhanced detection of this disease. This situation has confused the management of hyperparathyroidism since most patients now present with asymptomatic disease, and the need for surgical treatment is controversial in asymptomatic individuals. (2) Primary hyperparathyroidism usually is caused by hypersecretion of parathyroid hormone by an autonomously functioning parathyroid adenoma. In a small percentage of cases, multigland hyperplasia is present. In experienced hands, surgical removal of an adenoma within the thyroid bed cures the hyperparathyroidism 90% to 95% of the time, without performance of a preoperative procedure to localize the adenoma. Approximately 10% of parathyroid tissue is ectopic in location, however. Furthermore, approximately two thirds of "missed" adenomas are within the thyroid bed. Reexploration in the event of a failed operation therefore is not an uncommon occurrence. Parathyroid localization procedures clearly are indicated in patients with primary hyperparathyroidism who have evidence of persistent disease after a failed attempt at surgical cure. In patients first presenting with primary hyperparathyroidism, the need for a localization procedure is less clear, since surgery appears to be successful much of the time without it. Regardless of the nature of the above controversies, surgery for autonomous hyperparathyroidism continues, and localization procedures become more popular. Preoperative localization procedures such as angiography and venography with venous sampling for parathormone are cumbersome and invasive. Noninvasive tests to localize the parathyroid glands have emerged in the past 10 years, including dual tracer radionuclide scintigraphy with 201-thallous chloride and 99m-technetium pertechnetate, high-resolution computer tomography, and fine parts ultrasonography. Dual tracer scintigraphy with thallium and technetium is reported to have a localization sensitivity of 70%-90%. False-negative studies occur primarily in patients with small adenomatous or hyperplastic glands.(ABSTRACT TRUNCATED AT 400 WORDS)

Humans↗

[Portal vein resection in the framework of surgical therapy of pancreatic head carcinoma: clarification of indication by improved preoperative diagnostic procedures?].

Tumor invasion of the portal vein by ductal adenocarcinoma of the pancreatic head is classically known as a criterion for inoperability. Despite improvement in operation techniques for portal vein resection during Whipple's procedure and acceptable mortality and morbidity, in the case of uncertain tumor infiltration vascular resection cannot be recommended in general. The problem is the preoperative detection of tumor infiltration of the portal vein. Often the surgeon is confronted with unsuspected macroscopic portal vein infiltration or tumor adhesion during the operation. Between 1986 and 1995 105 patients underwent Whipple's procedure for ductal adenocarcinoma of the pancreatic head in our department. In eight of these cases partial portal vein resection was performed because of macroscopic tumor infiltration or tumor adhesion. In all eight cases the preoperative diagnostic procedures with CT and portography did not show any suspicion of tumor infiltration. In four of the eight cases histological tumor infiltration of all vascular layers was found. In the others we found no or only adventitial tumor invasion. The patients without tumor infiltration of the portal vein showed a survival time after surgery of 27.78 months in contrast to 6.67 months in the group with histologically proven tumor infiltration. Endovascular, intraportal ultrasound (IPEUS), a new diagnostic procedure, can give helpful information regarding portal vein involvement. Although the IPEUS is not a standard diagnostic procedure it was shown to detect portal vein infiltration with high sensitivity and specificity. Our results indicate that in such cases where portal vein infiltration has been excluded by IPEUS, patients with macroscopic tumor adhesion do benefit from partial portal vein resection.

Adult↗

Reduction in the number of sentinel lymph node procedures by preoperative ultrasonography of the axilla in breast cancer.

Currently, breast cancer patients without clinically suspicious lymph nodes are candidates for sentinel lymph node procedures (SLNPs). The aims of this study were to investigate whether preoperative axillary ultrasonography and fine-needle aspiration cytology (FNA) can reduce the number of the more time-consuming SLNPs, and to identify a subset of quantitative nodal features to predict metastatic involvement. 268 axillae were ultrasonographically examined. FNA was performed on suspicious nodes (smallest diameter > or =5 mm or atypical cortex appearance). SLNP was omitted if a tumour-positive node was found on FNA. Length, width, maximum cortex thickness and appearance of cortex and hilus were ultrasonographically established. In 93 axillae (35%), at least one node was detected with ultrasound. FNA was performed once per axilla on 66 nodes; 37 (56%) contained tumour cells. 31% of all tumour-positive axillae (macro-+micrometastases) was found by ultrasound and FNA (37/121). 41% of all axillae containing macrometastases was found by ultrasound and FNA (36/87). SLNPs were reduced by 14% (37/268). Maximum cortex thickness is the main feature to predict metastatic involvement (area under Receiver Operating Characteristic (ROC) curve (A(Z))=0.87).

Adult↗

Ultrasound-guided fine needle aspiration cytology of axillary lymph nodes in breast cancer patients. A preoperative staging procedure.

Currently, axillary lymph node dissection is increasingly being replaced by the sentinel node procedure. This method is time-consuming and the full immunohistochemical evaluation is usually only first known postoperatively. This study was designed to evaluate the accuracy of preoperative ultrasound-guided fine needle aspirations (FNAs) for the detection of non-palpable lymph node metastases in primary breast cancer patients. We evaluated the material of 183 ultrasound-guided FNAs of non-palpable axillary lymph nodes of primary breast cancer patients. The cytological results were compared with the final histological diagnosis. Ultrasound-guided FNA detected metastases in 44% (37/85) of histologically node-positive patients, in 20% of the total patient population studied. These pecentages are likely to be higher when women with palpable nodes are included. Cytologically false-negative and false-positive nodes were seen in 28 (15%) and three cases (1.6%), respectively. Interestingly 25% (n=7) of the false-negative nodes, revealed micrometastases on postoperative histology. The sensitivity was 57%, the specificity 96%. We conclude that ultrasound-guided FNA of the axillary lymph nodes is an effective procedure that should be included in the preoperative staging of all primary breast cancer patients. Whether lymph nodes are palpable or not, it will save considerable operating time by selecting those who need a complete axillary lymph node dissection at primary surgery and would save a significant number of sentinel lymph node dissections (SLNDs).

Biopsy, Needle↗

Preoperative localization procedures for initial surgery in primary hyperparathyroidism.

The experience of the surgeon and precise localization of abnormal parathyroid glands determine the success of surgery for primary hyperparathyroidism (HPT). In HPT patients undergoing repeat surgery, the use of localization studies improved the ability to identify the remaining abnormal parathyroid tissue. This study investigated the roles of preoperative localization techniques for initial surgery for primary HPT. From 1985 through 1997, two noninvasive localization procedures, ultrasonography (US) and 201thallium chloride-99mtechnetium pertechnetate subtraction scanning (Tl-Tc), were used prior to initial exploration for primary HPT in 76 patients. Their accuracy was determined on the basis of surgical and pathologic results. The surgical success rate was 96% (73/76). The sensitivities of US and Tl-Tc were 71% and 49%, respectively. The sensitivity of Tl-Tc was higher for the lower parathyroid glands. In 21 of 26 patients who underwent fine-needle aspiration (FNA) of the suspected enlarged parathyroid gland, the diagnosis of parathyroid adenoma was confirmed preoperatively. We conclude that the concomitant use of US and FNA is a safe and convenient method for preoperative localization of the parathyroid glands prior to initial surgical exploration in patients with primary HPT. Bilateral neck exploration by an experienced surgeon should be the routine procedure. US and Tl-Tc alone offer limited localization information, and unilateral exploration should be reserved for selected cases in which the results of these two imaging studies are consistent with one another.

Adult↗

An integrated functional magnetic resonance imaging procedure for preoperative mapping of cortical areas associated with tactile, motor, language, and visual functions.

OBJECTIVE: To evaluate an integrated battery of preoperative functional magnetic resonance imaging (fMRI) tasks developed to identify cortical areas associated with tactile, motor, language, and visual functions. METHODS: Sensitivity of each task was determined by the probability that a targeted region was activated for both healthy volunteers (n = 63) and surgical patients with lesions in these critical areas (n = 125). Accuracy of each task was determined by the correspondence between the fMRI maps and intraoperative electrophysiological measurements, including somatosensory evoked potentials (n = 16), direct cortical stimulation (n = 9), and language mapping (n = 5), and by preoperative Wada tests (n = 13) and visual field examinations (n = 6). RESULTS: For healthy volunteers, the overall sensitivity was 100% for identification of the central sulcus, visual cortex, and putative Wernicke's area, and 93% for the putative Broca's area (dominant hemisphere). For patients with tumors affecting these regions of interest, task sensitivity was 97% for identification of the central sulcus, 100% for the visual cortex, 91% for the putative Wernicke's area, and 77% for the putative Broca's area. These sensitivities were enhanced by the use of multiple tasks to target related functions. Concordance of the fMRI maps and intraoperative electrophysiological measurements was observed whenever both techniques yielded maps and Wada and visual field examinations were consistent with fMRI results. CONCLUSION: This integrated fMRI task battery offers standardized and noninvasive preoperative maps of multiple critical functions to facilitate assessment of surgical risk, planning of surgical routes, and direction of conventional, intraoperative electrophysiological procedures. Thus, a greater range of structural and functional relationships is brought to bear in the service of optimal outcomes for neurosurgery.

Adolescent↗

The value of preoperative screening procedures in stage I and II malignant melanoma.

Fifty patients with melanoma (30 with clinical Stage I disease and 20 with clinical Stage II disease) were analyzed retrospectively along with the screening test done prior to surgery. While the value of the chest X ray is unquestioned in preoperative screening, the same cannot be said of liver, brain, and bone scans. The bone marrow biopsy, however, done with a Janshidi needle was of value in detecting one patient with bone-marrow metastases who on examination had clinical Stage II disease and precluded surgery in this same individual. Therefore, we feel that in the preoperative scanning of patients with Stage I or Stage II human malignant melanoma, and especially in the latter, the bone-marrow biopsy should be done routinely in addition to a hematological profile, liver profile, and chest X ray.

Bone Marrow Examination↗

[Value of neuroradiologic procedures in preoperative assessment of cervical myelopathy].

The diagnostic value of computed tomography (CT), myelography, myelo-CT and magnetic resonance imaging (MRI) was retrospectively investigated in 94 patients in whom Cloward's operation had been performed due to symptoms of cervical myelopathy (CM). In 55 patients with "classical" cervical spondylotic myelopathy all investigated diagnostic procedures demonstrated a comparably high degree of sensitivity and specificity, thus proving comparable for diagnosing pathological alterations of the cervical spine. In 39 patients with CM as a consequence of an acute cervical disk prolapse, however, MRI was superior and offered the highest diagnostic accuracy. The following general diagnostic strategy in patients with CM can be suggested: Conventional plain film radiography of the cervical spine, axial CT of the involved segments and MRI of the cervical spine in sagittal and transversal orientation, using T1 and T2 weighted pulse sequences. The combined use of these techniques allows the exact evaluation of any relevant structure alterations of the cervical spine that determine differential therapeutic approaches.

Adult↗