Can members of the south-western Gila robusta species complex be distinguished by morphological features?

The goal for this project was to re-examine key morphological characters hypothesized to differentiate Gila intermedia, Gila robusta and Gila nigra and outline methods better suited for making species designations based on morphology. Using a combination of meristic counts, morphological measurements and geometric morphometrics, morphological dissimilarities were quantified among these three putative species. Traditional meristic counts and morphological measurements (i.e. distances between landmarks) were not useful for species identification. Geometric morphometrics, however, identified differences among species, while also suggesting an effect of geographic location on morphological variation. Using canonical variate analysis for the 441 fish sampled in this study, geometric morphometrics accurately predicted true group membership 100% of the time for G. nigra, 97% of the time for G. intermedia and 91% of the time for G. robusta. These results suggest that geometric morphometric analysis is necessary to identify morphological differences among the three species. Geometric morphometric analysis used in this study can be adopted by management officials as a tool to classify unidentified individuals.

A history of meniscal surgery: from ancient times to the twenty-first century.

The science and surgery of the meniscus have evolved significantly over time. Surgeons and scientists always enjoy looking forward to novel therapies. However, as part of the ongoing effort at optimizing interventions and outcomes, it may also be useful to reflect on important milestones from the past. The aim of the present manuscript was to explore the history of meniscal surgery across the ages, from ancient times to the twenty-first century. Herein, some of the investigations of the pioneers in orthopaedics are described, to underline how their work has influenced the management of the injured meniscus in modern times. Level of evidence V.

Pig thrombomodulin binds human thrombin but is a poor cofactor for activation of human protein C and TAFI.

Incompatibility between pig thrombomodulin (TM) and primate thrombin is thought to be an important factor in the development of microvascular thrombosis in rejecting pig-to-primate xenografts. To examine this interaction at the molecular level, we cloned pig TM and measured its ability to bind human thrombin and act as a cofactor for the activation of human protein C and TAFI. The 579-residue pig TM protein showed approximately 69% sequence identity to human TM. Within the EGF domains necessary for binding of thrombin (EGF56), protein C (EGF4) and TAFI (EGF3), all of the amino acids previously identified as critical for the function of human TM, with the exception of Glu-408 in EGF5, were conserved in pig TM. Comparison of transfected cells expressing pig or human TM demonstrated that both proteins bound human thrombin and inhibited its procoagulant activity. However, pig TM was a poor cofactor for the activation of human protein C and TAFI, with domain swapping showing that EGF5 was the most important determinant of compatibility. Thus, while pig TM may be capable of binding thrombin generated in the vicinity of xenograft endothelium, its failure to promote the activation of human protein C remains a significant problem.

Three Tesla MRI for the diagnosis of meniscal and anterior cruciate ligament pathology: a comparison to arthroscopic findings.

AIM: To assess the accuracy of 3T magnetic resonance imaging (MRI) in the evaluation of meniscal and anterior cruciate ligament (ACL) injury. MATERIALS AND METHODS: Sixty-one consecutive patients were identified who were referred for evaluation of suspected intra-articular pathology with a 3T MRI and who, subsequently, underwent an arthroscopic procedure of the knee were included for the study. Two musculoskeletal radiologists interpreted the images. The sensitivity, specificity, positive predictive value, and negative predictive value were then calculated for the MRI versus the arthroscopic findings as a reference standard. RESULTS: The sensitivity and specificity for the overall detection of meniscal tears in this study was 84 and 93%, respectively. The results for the medial meniscus separately were 91 and 93% and for the lateral 77 and 93%. The evaluation of ACL integrity was 100% sensitive and specific. The meniscal tear type was correctly identified in 75% of cases and its location in 94%. CONCLUSION: This study demonstrates good results of 3T MRI in the evaluation of the injured knee. Caution should still be given to the interpretation on MRI of a lateral meniscus tear, and it is suggested that the standard diagnostic criteria of high signal reaching the articular surface on two consecutive image sections be adhered to even at these higher field strengths.

Effect of antiplatelet therapy on thromboembolic complications of elective coil embolization of cerebral aneurysms.

BACKGROUND AND PURPOSE: Thromboembolic events are the most common complications of elective coil embolization of cerebral aneurysms. Administration of oral clopidogrel and/or aspirin could lower the thromboembolic complication rate. MATERIALS AND METHODS: Records over a 10-year period were reviewed in a retrospective cohort study. For 369 consecutive elective coil embolization procedures, 25 patients received no antiplatelet drugs, 86 received antiplatelet drugs only after embolization, and 258 received antiplatelet drugs before and after embolization. RESULTS: Symptomatic thromboembolic complications (transient ischemic attack or stroke within 60 days) occurred in 4 (16%) of 25 when no antiplatelet drugs were given, in 2 (2.3%) of 86 when antiplatelet drugs were administered only after embolization, and in 5 (1.9%) of 258 when antiplatelet drugs were administered before and after embolization. The lower symptomatic thromboembolic complication rate in the patients who received any antiplatelet therapy was statistically significant (P = .004). Clots were visible intraprocedurally in 5 (4.5%) of 111 when no antiplatelet drugs were administered before procedures and in 4 (1.6%) of 258 when they were (P value not significant). None of the 9 was symptomatic postprocedurally, but 7 were lysed or mechanically disrupted. Extracerebral hemorrhagic complications occurred in 0 (0%) of 25 when no antiplatelet drugs were given and in 11 (3.2%) of 344 when they were (P value not significant). CONCLUSION: Oral clopidogrel and/or aspirin significantly lowered the symptomatic thromboembolic complication rate of elective coil embolization of unruptured cerebral aneurysms. There were trends toward a lower rate of intraprocedural clot formation in patients given antiplatelet drugs before procedures and a higher hemorrhagic complication rate in patients given antiplatelet drugs. Benefits of antiplatelet therapy appear to outweigh risks.

Single-institution experience with matrix coils in the treatment of intracranial aneurysms: comparison with same-center outcomes with the use of platinum coils.

BACKGROUND AND PURPOSE: This study was undertaken to analyze the outcomes and treatment-related complications of the polyglycolic/polylactic acid (PGLA)-coated Matrix platinum coils in the treatment of intracranial aneurysms and compare these results with those derived from the same single-institutional experience with use of uncoated, bare platinum coils. MATERIALS AND METHODS: In this study, we compared 2 groups of patients in a retrospective fashion. The first group consisted of 70 consecutive patients who underwent 82 aneurysm treatments with Matrix coils during the 14-month period of study, from January 2003 to February 2004. We compared this cohort with 70 consecutive patients who underwent a total of 80 aneurysm treatments with bare platinum coils in the 12 months immediately preceding the use of PGLA-coated coils, from January through December 2002. We then recorded the treatment characteristics, angiographic outcomes, and any complications. RESULTS: There were similar baseline demographic characteristics between the 2 study groups except in age, anatomic location, and length of follow-up. The overall recurrence rate of aneurysms was 41% among the Matrix-treated group and 32% among the patients treated with bare platinum. Among the 42 patients treated with 100% Matrix, the rate of recurrence was 31%. Of the recurrences, 21% of the Matrix group, 19% of the 100% Matrix group, and 9% of the bare platinum group required retreatment. The overall rate of complications was 10% in the Matrix-treated group and 7% in the bare platinum group. There was not a statistically significant difference in the rate of recurrence of aneurysms or complications between the 2 groups. CONCLUSIONS: On the basis of our single-center experience, there is insufficient evidence to support the use of Matrix coils over bare platinum coils, given their disadvantages.

Flow Diversion in Ruptured Intracranial Aneurysms: A Meta-Analysis.

BACKGROUND: Flow diversion is now an established technique to treat unruptured intracranial aneurysms not readily amenable to endovascular coil embolization or open microsurgical occlusion. The role of flow-diverting devices in treating ruptured aneurysms is less clear. PURPOSE: To estimate rates of angiographic occlusion and good clinical outcome in patients with ruptured intracranial aneurysms treated with flow-diverting devices. DATA SOURCES: Systematic review of Ovid MEDLINE, PubMed, Cochrane databases, and EMBASE from inception to December 2015 for articles that included ruptured aneurysms treated with flow diversion. STUDY SELECTION: One hundred seventy-two records were screened, of which 20 articles contained sufficient patient and outcome data for inclusion. DATA ANALYSIS: Clinical and radiologic characteristics, procedural details, and outcomes were extracted from these reports. Aggregated occlusion rates and clinical outcomes were analyzed by using the Fisher exact test (statistical significance, α = .05). DATA SYNTHESIS: Complete occlusion of the aneurysm was achieved in 90% of patients, and favorable clinical outcome was attained in 81%. Aneurysm size greater than 7 mm was associated with less favorable clinical outcomes (P = .027). Aneurysm size greater than 2 cm was associated with a greater risk of rerupture after treatment (P < .001). LIMITATIONS: Observational studies and case reports may be affected by reporting bias. CONCLUSIONS: Although not recommended as a first-line treatment, the use of flow diverters to treat ruptured intracranial aneurysms may allow high rates of angiographic occlusion and good clinical outcome in carefully selected patients. Aneurysm size contributes to treatment risk because the rerupture rate following treatment is higher for aneurysms larger than 2 cm.

Wide Variability in Prethrombectomy Workflow Practices in the United States: A Multicenter Survey.

BACKGROUND AND PURPOSE: Clinical outcomes in patients with acute ischemic stroke caused by large vessel occlusion depend on the speed and quality of workflows leading to mechanical thrombectomy. In the absence of universally accepted best practices for workflow, developing stroke hospitals can benefit from improved awareness of real-world workflows in effect at experienced centers. To this end, we surveyed prethrombectomy workflow practices at stroke centers throughout the United States. MATERIALS AND METHODS: E-mail and phone interviews were conducted with neurointerventional team members at 30 experienced, endovascular-capable stroke centers. Questions were chosen to reflect workflow components of triage, team activation, transport, case setup, and anesthesia. RESULTS: There is wide variation in prethrombectomy workflows. At 53% of institutions, nonphysician staff respond to stroke alerts alongside physicians. Imaging triage involves noninvasive angiography or perfusion imaging at 97% and 63% of institutions, respectively. Neurointerventional consultation is initiated before the completion of neuroimaging at 86% of institutions, and the team is activated before a final treatment decision at 59%. The neurointerventional team most commonly arrives within 30 minutes. Patients may be transported to the neuroangiography suite before team arrival at 43% of institutions. Procedural trays are set up in advance of team arrival at 13% of centers; additional thrombectomy devices are centrally stored at 54%. A power injector for angiographic runs is consistently used at 43% of institutions. Anesthesiology routinely supports thrombectomies at 67% of institutions. CONCLUSIONS: Prethrombectomy workflows vary widely between experienced centers. Improved awareness of real-world workflows and their variations may help to guide institutions in designing their own protocols of care.

CDH1 associated gastric cancer: a report of a family and review of the literature.

AIMS: Hereditary diffuse gastric cancer (HDGC) is an autosomal-dominant inherited form of gastric cancer associated with inactivating germline mutations in the CDH1 gene. We set out to outline the role of CDH1 in HDGC. Investigation of a family suspected as having HDGC is discussed. The role of surgery in the management of affected individuals is then examined. METHODS: A search was conducted of Medline and the National Library of Medicine to identify key articles concerning CDH1 gene mutations, familial gastric cancer and gastrectomy. Further, relevant articles were obtained by manual scanning of the reference lists of identified papers. Mutation-specific CDH1 genetic testing was performed on six living family members and on gastric tissue obtained from two deceased members. RESULTS: CDH1 mutations cause inactivation of the cell adhesion protein E-cadherin. Carriers of the CDH1 germline gene mutation develop an aggressive, diffuse, submucosal gastric cancer at an early age. Current endoscopic screening is ineffective at detecting HDGC. The presence of a CDH1 germline gene mutation was confirmed in both deceased family members and also in four of the six living members tested. CONCLUSION: Genetic counselling and CDH1 gene mutation testing is indicated in families with suspected HDGC. In the absence of a satisfactory surveillance mechanism, prophylactic total gastrectomy would appear to be an appropriate therapeutic option in mutation carriers.

The role of sentinel lymph node biopsy in ductal carcinoma in situ.

AIM: To review the role of sentinel lymph node (SLN) biopsy in the surgical management of patients with ductal carcinoma in situ (DCIS). METHODS: A search was conducted of Medline and the National Library of Medicine to identify key articles concerning DCIS, SLN biopsy (SLNB) and axillary dissection. Further relevant articles were obtained from the references cited in the literature. RESULTS: Up to 20% of patients with a core biopsy diagnosis of DCIS will be later up-staged based on an invasive component identified on the excision specimen. Quality assurance in breast screening programmes requires minimally invasive pre-operative diagnosis and also axillary sampling in the case of documented invasive disease. As an effective and validated procedure, SLNB represents a paradigm shift in the surgical management of the axilla for patients with invasive breast cancer. It remains undefined which, if any, subgroups of patients with DCIS should undergo SLNB. CONCLUSION: Axillary lymphadenectomy is an overtreatment for patients with DCIS. Performing a SLNB during the initial procedure may avoid a second operation in some DCIS patients who are diagnosed with occult invasive disease at their definitive operation. When predictors of hidden invasive disease are clarified by further study, SLNB may be used in the management of selected high-risk DCIS patients.

Dosimetry of CT-guided volumetric IR-192 brain implant.

Over the past 2 years, an afterloading technique has been developed and refined to implant radioactive Ir-192 sources into brain tumors. The implantation procedure integrates a stereotaxic system with computerized tomography (CT), which provides tumor position, volume, and guides the placement of catheters. A radiolucent ring-frame immobilizes the head as holes are made at 1 cm intervals with the aid of a template. Catheters containing dummy sources 1 cm apart are then inserted to the desired depth, and their position verified in three dimensions to insure complete coverage of visible tumor volume as defined by contrast enhancement. Once catheters are secured, the anesthetized patient is moved to the intensive care unit where the dummy sources are replaced by ribbons of Ir-192 seeds (specific activity 0.6-1.0 mg Ra eq). CT scans with the dummy sources in place are used to designate spatial coordinates of the active sources. A computer program converts position data and source strength into isodose contours in any plane. The implant duration (70-100 hours) for the desired dose to the tumor periphery (60-120 Gy) is then calculated. Dose rate contours are superimposed on preimplant CT scans. Maximum and minimum doses are determined in each of the various planes. Verification dosimetry has been carried out with thermoluminescent dosimeters placed in a catheter located in a plane along the tumor periphery. In vivo isodose values compared to idealized plans agree within +/-5%-10%.

Binary nature and radiographic identifiability of craniosynostosis.

RATIONALE AND OBJECTIVES: Two independent gold standards and diagnoses from three-dimensional computed tomography (CT) images were used to examine the possibility that craniosynostosis is a binary abnormality that potentially may be diagnosed without error. METHODS: Surgical reports, histology of excised sutures, and three-dimensional CT images were compared for 25 children undergoing surgical management of craniosynostosis. Surgical reports identified sutures as normal or abnormal. Histology reported suture closure on a 5-point scale. Four radiologists used three-dimensional CT images to diagnose sutures on a 6-point rated response scale. RESULTS: Sutures with histology 0, 1, or 2 were normal on surgical reports, and those with histology 3 or 4 were abnormal. Most readers achieved nearly perfect sensitivity and specificity. Reader confidence was unrelated to degree of pathology. CONCLUSION: Craniosynostosis appears to be binary in our sample. Surgical reports, pathology results, and three-dimensional CT images read by experienced viewers achieved nearly perfect agreement.

Bleeding complications after basilar artery fibrinolysis with tissue plasminogen activator.

BACKGROUND AND PURPOSE: Fibrinolysis with local intraarterial urokinase infusion for basilar artery thrombosis has been associated with a low rate of spontaneous symptomatic cerebral hemorrhage, even when patients have been treated late in the course of symptoms. Because urokinase is presently unavailable in the United States, this study was undertaken to determine the frequency of spontaneous cerebral hemorrhage in basilar artery fibrinolysis performed with tissue plasminogen activator (tPA). METHODS: In a retrospective review of our initial experience with cerebral fibrinolysis for acute stroke using intraarterial tPA, four cases of basilar thrombosis were identified. Doses of the fibrinolytic agent and heparin, angiographic findings, clinical courses, and bleeding complications for these patients were determined. These results were compared with those from a prior study of 20 similar consecutive patients treated with urokinase. RESULTS: Symptom duration before treatment was unlimited. Intraarterial doses of tPA were 20 to 50 mg. Patients received full systemic anticoagulation with heparin. Complete basilar artery recanalization was achieved in 75% of patients. Two patients treated with tPA had angioplasty and stent placement for related high-grade stenosis. Spontaneous symptomatic cerebral hemorrhage occurred in three (75%) of the four tPA-treated patients and in three (15%) of the 20 urokinase-treated patients. CONCLUSION: The cerebral hemorrhage complication rate for intraarterial fibrinolysis with tPA was very high in cases of basilar artery thrombosis at the doses we used. Protocol adjustments should be considered.

Relationship between clot location and outcome after basilar artery thrombolysis.

PURPOSE: To identify factors that predict survival and good neurologic outcome in patients undergoing basilar artery thrombolysis. METHODS: Over a 42-month period, 20 of 22 consecutive patients with angiographic proof of basilar artery thrombosis were treated with local intraarterial urokinase. Brain CT scans, neurologic examinations, symptom duration, clot location, and degree of recanalization were analyzed retrospectively. RESULTS: Overall survival was 35% at 3 months. Survival in patients with only distal basilar clot was 71%, while survival in patients with proximal or midbasilar clot was only 15%. At 3 months, 29% of patients with distal basilar clot and 15% of patients with proximal or midbasilar clot had good neurologic outcomes (modified Rankin score of 0 to 2 and Barthel index of 95 to 100). Complete recanalization was achieved in 50% of patients; 60% of those survived and 30% had good neurologic outcomes. Of patients with less than complete recanalization, only 10% survived. Neither duration of symptoms before treatment (range, 1 to 79 hours), age (range, 12 to 83 years), nor neurologic status at the initiation of treatment (Glasgow Coma Scale score range, 3 to 15) predicted outcome. Pretreatment CT findings (positive or negative for related ischemic changes) did not predict outcome or hemorrhagic transformation. CONCLUSION: The single best predictor of survival after basilar thrombosis and intraarterial thrombolysis was distal clot location. Complete recanalization favored survival. Radiologically evident related infarctions, advanced age, delayed diagnosis, and poor pretreatment neurologic status did not predict poor outcome and therefore should not be considered absolute contraindications for intraarterial thrombolysis in patients with basilar artery thrombosis.

Intraoperative digital subtraction angiography: a review of 112 consecutive examinations.

PURPOSE: To examine the effect of intraoperative angiography on neurosurgery and angiographic technical success, safety, and accuracy. METHODS: Angiographic studies, surgical reports, and hospital records were reviewed retrospectively for 112 consecutive procedures in which intraoperative angiography was performed during neurosurgery. The results of conventional postoperative angiograms in 28 of the 112 procedures were also reviewed. A portable digital subtraction angiography unit was used for all patients. Decisions in the operating room were based on review of stored videotaped images. RESULTS: Eighteen studies were obtained in 14 patients after arteriovenous malformation resection. Unsuspected residual nidus was identified and resected in 3 patients. The intraoperative angiogram also altered therapy for 2 patients undergoing staged resections of arteriovenous malformations. Sixty-six studies were performed after aneurysm clipping, with clinically significant changes in surgical therapy made in 5 patients. Of 28 examinations after carotid endarterectomy, 3 led to revision. Two complications of angiography occurred. One led to a permanent neurologic deficit, yielding a complication rate of 1.5% for stroke. Two examinations could not be completed because of technical factors. Two false-negative examinations were identified on postoperative studies. One patient with a normal intraoperative study after carotid endarterectomy thrombosed the repaired internal carotid artery after surgery. CONCLUSIONS: Intraoperative angiography altered surgery in 13 of 112 procedures on 104 patients. This study supports the use of intraoperative angiography in arteriovenous malformation resection and in complex aneurysm surgery, but not for routine carotid endarterectomy.

Polyvinyl alcohol particle size and suspension characteristics.

PURPOSE: To evaluate the size and shape of commercially available polyvinyl alcohol (PVA) particles and to determine whether they change in size when suspended in nonionic contrast and in a solution of nonionic contrast and absolute alcohol. METHODS: The two-dimensional area and the long and short axis of PVA particles from several different vendors were measured using a light microscope attached to a video system and an image-processing software program. Particles were measured as packaged (dry or suspended in saline), suspended in ioversol, and suspended in ioversol containing 30% alcohol. RESULTS: All brands of dry particles had similar microscopic appearances. The saline-suspended particles had fewer and finer perforations. After suspension in contrast, all sizes and brands of dry particles significantly increased in size. The particles packaged in saline did not expand. The addition of alcohol to the contrast did not consistently change particle size. Particle aggregation was similar in both contrast suspensions for all groups of particles. Particles less than 50 microns in size were rarely observed in any PVA preparation after suspension. CONCLUSIONS: The three dry PVA preparations seem to be similar. All increase significantly in size when suspended in nonionic contrast or contrast-alcohol solutions. The saline-packaged PVA particles were different from the dry variety and did not enlarge in contrast or contrast-alcohol solutions. Alcohol did not change the size or suspension characteristics of PVA particles. Particles less than 50 microns in size were rarely identified.

Radiation dose to patients and personnel during intraoperative digital subtraction angiography.

BACKGROUND AND PURPOSE: The use of intraoperative angiography to assess the results of neurovascular surgery is increasing. The purpose of this study was to measure the radiation dose to patients and personnel during intraoperative angiography and to determine the effect of experience. METHODS: Fifty consecutive intraoperative angiographic studies were performed during aneurysmal clipping or arteriovenous malformation resection from June 1993 to December 1993 and another 50 from December 1994 to June 1995. Data collected prospectively included fluoroscopy time, digital angiography time, number of views, and amount of time the radiologist spent in the room. Student's t-test was used to assess statistical significance. Effective doses were calculated from radiation exposure measurements using adult thoracic and head phantoms. RESULTS: The overall median examination required 5.2 minutes of fluoroscopy, 55 minutes of operating room use, 40 seconds of digital angiographic series time, and four views and runs. The mean room time and the number of views and runs increased in the second group of patients. A trend toward reduced fluoroscopy time was noted. Calculated effective doses for median values were as follows: patient, 76.7 millirems (mrems); radiologist, 0.028 mrems; radiology technologist, 0.044 mrems; and anesthesiologist, 0.016 mrems. CONCLUSION: Intraoperative angiography is performed with a reasonable radiation dose to the patient and personnel. The number of angiographic views and the radiologist's time in the room increase with experience.

Chondrosarcoma of the larynx: CT features.

PURPOSE: To define the typical CT features of chondrosarcoma of the larynx. PATIENTS AND METHODS: Results of CT studies, performed on 10 patients with pathologically proved chondrosarcoma of the larynx, were retrospectively reviewed and correlated with clinical presentation. RESULTS: In all patients, the mass was detected on CT. The most frequent site of origin of the tumor was the cricoid cartilage (nine cases) followed by the thyroid cartilage (one case). Coarse or stippled calcification within the tumor was the most helpful radiologic finding and was seen in every case. In eight patients, the tumor had both an endolaryngeal and an extralaryngeal growth pattern, whereas in two patients the tumor was entirely endolaryngeal. Hoarseness, dyspnea, and dysphagia were the most common symptoms. In all patients presenting with dyspnea, the tumor exhibited endolaryngeal components. In patients presenting with hoarseness, three tumors had endolaryngeal and extralaryngeal components and two tumors were entirely endolaryngeal. CONCLUSION: Cross-sectional imaging afforded excellent evaluation of the airway as well as the extralaryngeal component of the tumor.

Effect of intraarterial papaverine on cerebral circulation time.

PURPOSE: To measure the mean cerebral circulation time (CCT) in patients with symptomatic vasospasm stemming from subarachnoid hemorrhage and to determine any change after papaverine treatment. METHODS: We studied 27 patients who received intraarterial papaverine from November 1992 to August 1995 to determine the CCT in 59 carotid territories. CCT was measured from the first image in which contrast was seen above the supraclinoid internal carotid artery to the peak filling of parietal cortical veins. Angiograms at the time of presentation were examined in 19 of the 27 patients. A control population of 19 patients (30 carotid territories) was also studied. RESULTS: The mean CCT on presentation was 6.8 seconds +/- 1.1. The prepapaverine mean CCT was 6.1 seconds +/- 1.2. The immediate postpapaverine mean CCT was 3.8 seconds +/- 0.8. CCT decreased in 58 of 59 territories treated with papaverine; the mean change was -35.7%. In eight of these patients, CCT rose on the following day to 6.1 seconds +/- 1.1. In the control group, mean CCT was 5.9 seconds +/- 0.8. The mean CCT in patients with subarachnoid hemorrhage was slightly prolonged on presentation relative to that in control subjects. CONCLUSION: Intraarterial papaverine produces a consistent decrease in CCT in patients with vasospasm.

Rapid enlargement of a posterior communicating artery aneurysm after Guglielmi detachable coil treatment of ipsilateral carotid artery aneurysms.

This case illustrates rapid aneurysm enlargement, presumably due to altered hemodynamics resulting from endovascular treatment of aneurysms on the same artery. We postulate that increased hemodynamic force directed to the inflow zone of the posterior communicating artery aneurysm was caused by the treatment of the two ophthalmic artery aneurysms. Originally, many of the flow vectors may have been directed into the larger ophthalmic segment aneurysm, located on the outside of the curve of the internal carotid artery. After treatment, flow may have been directed more smoothly around the carotid siphon and into the posterior communicating artery aneurysm.