Ventricular Entry Research Articles

Complications of ventricular entry during craniotomy for brain tumor resection.

OBJECTIVE Recent studies have demonstrated that periventricular tumor location is associated with poorer survival and that tumor location near the ventricle limits the extent of resection. This finding may relate to the perception that ventricular entry leads to further complications and thus surgeons may choose to perform less aggressive resection in these areas. However, there is little support for this view in the literature. This study seeks to determine whether ventricular entry is associated with more complications during craniotomy for brain tumor resection. METHODS A retrospective analysis of patients who underwent craniotomy for tumor resection at Henry Ford Hospital between January 2010 and November 2012 was conducted. A total of 183 cases were reviewed with attention to operative entry into the ventricular system, postoperative use of an external ventricular drain (EVD), subdural hematoma, hydrocephalus, and symptomatic intraventricular hemorrhage (IVH). RESULTS Patients in whom the ventricles were entered had significantly higher rates of any complication (46% vs 21%). Complications included development of subdural hygroma, subdural hematoma, intraventricular hemorrhage, subgaleal collection, wound infection, urinary tract infection/deep venous thrombosis, hydrocephalus, and ventriculoperitoneal (VP) shunt placement. Specifically, these patients had significantly higher rates of EVD placement (23% vs 1%, p < 0.001), hydrocephalus (6% vs 0%, p = 0.03), IVH (14% vs 0%, p < 0.001), infection (15% vs 5%, p = 0.04), and subgaleal collection (20% vs 4%, p < 0.001). It was also observed that VP shunt placement was only seen in cases of ventricular entry (11% vs 0%, p = 0.001) with 3 of 4 of these patients having a large ventricular entry (defined here as entry greater than a pinhole [< 3 mm] entry). Furthermore, in a subset of glioblastoma patients with and without ventricular entry, Kaplan-Meier estimates for survival demonstrated a median survival time of 329 days for ventricular entry compared with 522 days for patients with no ventricular entry (HR 1.13, 95% CI 0.65-1.96; p = 0.67). CONCLUSIONS There are more complications associated with ventricular entry during brain tumor resection than in nonviolated ventricular systems. Better strategies for management of periventricular tumor resection should be actively sought to improve resection and survival for these patients.

Periventricular glioblastomas and ependymal involvement interrogated using intraoperative fluorescence – a pathological correlative study

Rationale: Subventricular zone (SVZ) involvement has been proposed as an adverse prognostic factor in glioblastomas (GBM). The true extent of ventricular involvement at surgery is often difficult to establish and is poorly studied. Tumour fluorescence provides us with an exciting opportunity to interrogate tumour extent intraoperatively.Methods: We conducted a retrospective analysis of all cases of GBMs operated using aminolevulinic acid-induced fluorescence and analyzed radiological SVZ involvement alongwith the incidence of ventricular entry at surgery, ependymal fluorescence and histological correlation of the ependymal involvement.Results: Of 30 GBMs, radiological SVZ involvement was seen in 26 of which ventricles were opened at surgery in 19. Diffuse ependymal fluorescence was seen in 10 of the 19 cases (51%) and histology revealed tumour infiltration in only one of the five cases where ependymal tissue was sampled. Focal ependymal fluorescence seen in two of the 19 cases was always pathological. Diffuse ependymal fluorescence did not always correlate with gross appearance of the ventricular lining at surgery. Nor did it correlate with SVZ involvement.Conclusions: Pathological significance of diffusely fluorescing ependymal lining seen during surgery is questionable and need not represent tumour extension. Ependymal fluorescence may sometimes not be visualized even when the tumour appears to involve the SVZ. These results highlight the potential limitations of fluorescence especially in the bordering infiltrating zone where its predictive value is diminished.

Pattern of recurrence and factors associated with cerebrospinal fluid dissemination of glioblastoma in Chinese patients.

Background:Pattern of recurrence of glioblastoma (GBM) seems to have undergone some shifts from distant metastasis as a rarity to a higher proportion, including disease disseminated via cerebrospinal fluid (CSF) pathway. There is still no report on the pattern of recurrence for Chinese population. Here, we evaluated the pattern of recurrence of GBM in Chinese patients along with factors that could affect the distribution of recurrence.Methods:Medical records of GBM patients with definite recurrence were reviewed. Local recurrence was defined as tumor regrowth within the preoperative abnormal signals on magnetic resonance imaging (MRI) T2 sequence. New recurrence was a new lesion away from the preoperative T2 abnormalities. New recurrence in contact with CSF pathways was registered as new CSF dissemination. Progress-free survival (PFS) and survival after progress were compared using the Kaplan–Meier survival curves. Potential risk factors for new CSF dissemination were assessed using univariate models followed by multivariate analysis.Results:Thirty-six patients were proven to have recurrence; 22 local and 14 new recurrences. Among the 14 patients, 11 had new CSF dissemination. Median PFS for local, new parenchymal recurrence, and new CSF dissemination were 5.5 months, 9.9 months, and 12.1 months, whereas survival after progress were 6.1 months, 5.7 months, and 16.9 months, respectively. The ventricular entry during surgery and the completion of concomitant chemoradiotherapy were risk factors for new CSF dissemination. O6-methylguanine-DNA methyltransferase methylation was associated with the development of CSF dissemination.Conclusion:The majority of recurrence remained local (22/36, 61%). However, CSF dissemination was up to 30% (11/36). PFS for patients with CSF dissemination was the longest, and paradoxically survival after progress was the shortest. Ventricular entry should be avoided. Whole craniospinal MRI surveillance should be included for these patients.

Surgical Ventricular Entry is a Key Risk Factor for Leptomeningeal Metastasis of High Grade Gliomas.

Leptomeningeal metastasis (LM) of high grade gliomas (HGG) can lead to devastating disease courses. Understanding of risk factors for LM is important to identify patients at risk. We reviewed patient records and magnetic resonance imaging (MRI) of all patients with a first diagnosis of HGG who underwent surgery in our institution between 2008 and 2012. To assess the influence of potential risk factors for LM and the impact of LM on survival multivariate statistics were performed. 239 patients with a diagnosis of HGG and at least 6 months of MRI and clinical follow-up were included. LM occurred in 27 (11%) patients and was symptomatic in 17 (65%). A strong correlation of surgical entry to the ventricle and LM was found (HR: 8.1). Ventricular entry was documented in 137 patients (57%) and LM ensued in 25 (18%) of these. Only two (2%) of 102 patients without ventricular entry developed LM. Median overall survival of patients after diagnosis of LM (239 days) was significantly shorter compared to patients without LM (626 days). LM is a frequent complication in the course of disease of HGG and is associated with poor survival. Surgical entry to the ventricle is a key risk factor for LM.

Frequency and predictors of post-operative pericardial effusion requiring drainage following percutaneous epicardial access in the electrophysiology laboratory

Purpose: Percutaneous pericardial access is increasingly performed for mapping and ablation. Pericardial fat irritation, disruption of intrapericardial vessels, inadvertent right ventricular entry and periprocedural anticoagulation may predispose towards pericardial effusion but post-operative pericardial drains are associated with pain and pericarditis. While intra-procedural fluid accumulation is managed with existing epicardial access, post-procedural development of pericardial effusion following drain removal requires a separate invasive procedure with inherent risks. We sought to identify the frequency and predictors of pericardial effusion following epicardial sheath removal. Methods: All patients who underwent attempted epicardial access as part of an electrophysiology procedure were included in this retrospective study. Baseline clinical and echocardiography characteristics were collected. Patients who developed pericardial effusion requiring a separate pericardiocentesis following ablation were identified and compared to those who did not develop this complication. Results: Between 1/2004 and 12/2011, 116 pericardial access attempts were made in 107 consecutive patients (94.4% successful). Of these, 9 (7.8%) patients developed post-operative pericardial effusion requiring repeat access and drainage, an average of 1 day post-operatively. Patients with post-operative effusion tended to be younger (42.2 vs 51.8 years, P=0.05), and have a higher ejection fraction (EF, 55.6% vs. 44.6% P=0.03). There was no difference in gender (44.4 vs. 32.7% female), BMI (mean 29.3 vs. 29.4), inferior (vs. anterior) access (77.8 vs. 61.5%), peri-operative heparin use, and epicardial mapping only vs. epicardial mapping and ablation (44.4 vs. 56.1%) in patients with and without pericardial effusion (P>0.05). Three percent of patients with EF <55% had a pericardial effusion, vs. 18% with EF≥55%, P=0.02. Conclusion: Pericardial effusion requiring repeat access and drainage occurred in 7.8% of patients shortly after epicardial mapping/ablation procedures, and was more common in younger patients with normal ejection fraction. This may be due to increased trauma risk with vigorous ventricular contraction, and suggests that pericardial drains are best left in place post-procedure in young patients with ejection fraction of 50-55%.

The expression status of CD133 is associated with the pattern and timing of primary glioblastoma recurrence.

Glioblastoma carries a poor prognosis primarily because of its high rate of recurrence. The ability to predict the recurrence pattern and timing would be highly useful for determining effective treatment strategies. We examined the correlation between prognostic factors and the pattern of recurrence in patients with primary glioblastoma. In particular, we examined whether there was a correlation between the expression of CD133 and glioblastoma recurrence. We retrospectively analyzed 112 patients with primary glioblastoma. The timing and pattern (local or distant) of the initial recurrence were obtained from medical records. To identify factors predictive of recurrence, we examined CD133 expression by Western blots and immunohistochemistry, clinical (age, sex, KPS, Ki67 labeling index, surgery, ventricular entry) and genetic (IDH1, 7p, 9p, 10q, MGMT) factors. Of the 112 patients, 99 suffered recurrence. The first recurrence was local in 77 patients and distant in 22 patients. Among the factors to predict the pattern of recurrence, CD133 expression was significantly higher in distant than in local recurrence. Of the factors to predict the timing of recurrence, high CD133 expression was associated with shorter time to distant recurrence in both univariate and multivariate analyses (P = .0011 and P = .038, respectively). The expression of CD133 may be a predictor of the pattern and timing of recurrence of primary glioblastoma.

Recurrent cerebrospinal fluid shunt infection and the efficacy of reusing infected ventricular entry sites

The objective of this investigation was to review the clinical characteristics of recurrent CSF shunt infections in a large pediatric neurosurgical practice and to assess the safety and efficacy of reusing original ventricular entry sites for external ventricular drainage during treatment of infections and for subsequent reinsertion of shunts. Prospectively accrued clinical data on all patients treated at Children's Hospital Colorado for CSF shunt infections within a 10.5-year span were retrospectively investigated. One hundred twenty-one consecutive cases of CSF shunt infection met inclusion criteria. Recurrent shunt infection attributable to the management of these infections occurred in 14 cases (11.6%). Three recurrent infections were with their original organisms, 7 were organisms different from the original organisms, and 4 were indeterminate. Half or more of recurrent shunt infections were with organisms different from the original organism, and hence were new-type infections introduced during the management of the original infections. Incomplete eradication of original pathogens accounted for 3 (21.4%) of the 14 recurrent infections. Reusing recently infected or contaminated ventricular entry sites, both for CSF drainage during treatment and for implantation of new shunts, was as safe, with regard to risk of recurrent infection, as switching to new entry sites. Prior evidence of shunt infection is not, alone, a sufficient reason to change to a previously well-functioning site, and reuse of contaminated ventricular entry sites avoids all risks associated with making new ventricular entries.

Percutaneous mitral balloon valvotomy in a case of situs inversus dextrocardia with severe rheumatic mitral stenosis

The efficacy, safety and applicability of Inoue balloon technique for BMV are clearly established worldwide in selected subset of patients with rheumatic mitral stenosis (MS). However, in altered cardiac anatomy it offers technical challenges. Distorted cardiac anatomy and cardiac malpositions considerably increase the complications involved in interatrial septal puncture and left ventricular entry during BMV. There are only a few reports worldwide on successful BMV in altered cardiac anatomy using the standard Inoue technique. Here we describe a case of a 27-year-old female with situs inversus and dextrocardia, where BMV was successfully performed with a few modifications of the standard Inoue technique previously described in similar patients.

Implication of 5-aminolevulinic acid fluorescence of the ventricular wall for postoperative communicating hydrocephalus associated with cerebrospinal fluid dissemination in patients with glioblastoma multiforme: a report of 7 cases

Fluorescence-guided surgery using 5-aminolevulinic acid (5-ALA) has been broadly recognized as a beneficial tool for the resection of glioblastoma multiforme (GBM). Fluorescence in the ventricular walls, which were apparently free of macroscopic tumor or MR imaging enhancement indicative of CSF dissemination, was detected during surgery for GBM. To evaluate the clinical significance of the 5-ALA fluorescence, the authors resected ventricle wall tissue together with the adjacent tumors for pathological examination and then followed up the clinical courses of the patients. Seven consecutive GBMs located near the lateral ventricle were surgically treated using a fluorescence-guided technique with 5-ALA at the authors' hospital since acquiring instrumentation for the detection of 5-ALA fluorescence in 2007. All of the procedures were performed using a ventricular entry, and 5-ALA fluorescence of the ventricular wall was detected despite the absence of macroscopic tumor invasion of the wall. A pathological examination of the resected ventricular wall tissues revealed tumor cells in 6 of the 7 cases and disruption of the ependymal cell layer in all 7 cases. Delayed communicating hydrocephalus followed surgery in all 7 patients, and ventricular wall enhancements on MR imaging were demonstrated after hydrocephalus in 2 of the patients. Data in this study suggest that 5-ALA fluorescence of the ventricular wall may be predictive of postoperative hydrocephalus associated with CSF dissemination even in cases without evidence of CSF dissemination on MR imaging studies before surgery. The authors also speculate that postoperative radiotherapy covering the whole ventricular system may be a better therapeutic option for these patients.

Reuse of ventricular drain sites for cerebrospinal fluid shunting in patients with no prior infection

The safety of reusing ventricular drain sites for shunting CSF in patients with no history of infection involving either the ventricular drain or the CSF was the focus of this investigation. Prospectively accrued clinical data on all patients who, in an 8-year span ending in June 2008, underwent external ventricular drain placement and subsequently required CSF shunts were retrospectively evaluated for evidence of shunt infection and other complications. The infection rate for 50 consecutive operations in 50 patients who met the inclusion criteria was 2.0%. Data from this study support the position that the reuse of ventriculostomy tracts when implanting first-time CSF shunts is, with regard to the risk of infection, a safe practice and avoids all risks associated with making a new ventricular entry.

Risk Factors, Echocardiographic Patterns, and Outcomes in Patients With Acute Ventricular Septal Rupture During Myocardial Infarction

Ventricular septal rupture (VSR), which can complicate an acute myocardial infarction (MI), carries a high mortality rate. Because precordial and transesophageal echocardiography can identify the type of rupture and assess right ventricular (RV) function at the patient's bedside, we examined the prognostic significance of echocardiographic patterns in postinfarct VSR by postulating that complex rupture and RV involvement carry a worse prognosis. Seventeen patients (10 men; mean age 66 years) who had confirmed postinfarct VSR underwent precordial and transesophageal echocardiography followed by coronary angiography. Serial 12-lead and right precordial leads were also available. Type of septal rupture was classified as simple or complex based on autopsy-proved echocardiographic criteria. Three patients had inferior wall MI and 14 had anterior wall MI. ST-segment elevation persisted >72 hours in all 3 patients who had inferior wall MI and in 12 who had anterior wall MI. Segmental wall motion abnormalities helped in detecting the left ventricular entry site, and use of unconventional views superimposed with color flow Doppler provided the RV exit site. RV function was better appreciated with transesophageal echocardiography. Two patients who had inferior wall MI and 7 who had anterior wall MI had complex ruptures. All 3 patients who had inferior wall MI and 7 who had anterior wall MI had electrocardiographic and echocardiographic evidence of RV involvement. Mortality rate was higher in patients who had complex rupture (78% vs 38%, p <0.001) and in those who had RV extension (71% vs 29%, p <0.001). In conclusion, persistent ST elevation is a common finding in patients who have postinfarct VSR. Complex VSR and RV involvement are significant determinants of clinical outcome.

Outcomes of clinically significant idiopathic pericardial effusion requiring intervention

There is a paucity of outcome data on patients with idiopathic pericardial effusion requiring intervention. All patients who had clinically significant pericardial effusion confirmed by echocardiography and requiring interventions between 1979 and 2000 were identified through the Echo-guided Pericardiocentesis Registry and Echocardiography and Surgical Databases. Clinical data and outcomes were obtained by review of medical records and surveys. The study population consisted of 92 patients (mean age 59 ± 15 years). Five patients were referred directly for pericardiectomy (3 had effusion in the context of chronic relapsing pericarditis, 2 had effusive constrictive disease), and 87 underwent echo-guided pericardiocentesis as thier initial treatment. In 47 of these patients, primary management involved extended pericardial catheter drainage, which was associated with a trend to lower recurrence rates than in those without catheter drainage (p = 0.052). Three patients had transient right ventricular entry with no sequelae, and 7 patients (8%) later had surgical pericardiectomy because of the recurrence of effusion, 2 of whom were also found to have evidence of effusive constrictive disease during surgery. One patient had bleeding after pericardiectomy that required repeat thoracotomy. Mean follow-up of the cohort was 3.8 ± 4.3 years. For most patients with clinically significant idiopathic pericardial effusion requiring intervention, echo-guided pericardiocentesis was the definitive treatment. Pericardiectomy was necessary for patients in whom effusion occurred in the context of effusive constrictive disease, chronic relapsing pericarditis, or recurrent effusion despite pericardiocentesis. The prognosis for the cohort was favorable, and survival did not appear to differ from that of the general population (p = 0.372).

Outcomes of clinically significant idiopathic pericardial effusion requiring intervention

There is a paucity of outcome data on patients with idiopathic pericardial effusion requiring intervention. All patients who had clinically significant pericardial effusion confirmed by echocardiography and requiring interventions between 1979 and 2000 were identified through the Echo-guided Pericardiocentesis Registry and Echocardiography and Surgical Databases. Clinical data and outcomes were obtained by review of medical records and surveys. The study population consisted of 92 patients (mean age 59 ± 15 years). Five patients were referred directly for pericardiectomy (3 had effusion in the context of chronic relapsing pericarditis, 2 had effusive constrictive disease), and 87 underwent echo-guided pericardiocentesis as thier initial treatment. In 47 of these patients, primary management involved extended pericardial catheter drainage, which was associated with a trend to lower recurrence rates than in those without catheter drainage (p = 0.052). Three patients had transient right ventricular entry with no sequelae, and 7 patients (8%) later had surgical pericardiectomy because of the recurrence of effusion, 2 of whom were also found to have evidence of effusive constrictive disease during surgery. One patient had bleeding after pericardiectomy that required repeat thoracotomy. Mean follow-up of the cohort was 3.8 ± 4.3 years. For most patients with clinically significant idiopathic pericardial effusion requiring intervention, echo-guided pericardiocentesis was the definitive treatment. Pericardiectomy was necessary for patients in whom effusion occurred in the context of effusive constrictive disease, chronic relapsing pericarditis, or recurrent effusion despite pericardiocentesis. The prognosis for the cohort was favorable, and survival did not appear to differ from that of the general population (p = 0.372).

Delayed hydrocephalus after resection of supratentorial malignant gliomas.

To report our experience with 12 patients who developed delayed hydrocephalus after resection of supratentorial malignant gliomas. The charts of all affected patients were analysed retrospectively for clinical presentation, time interval between initial operation and occurrence of hydrocephalus, neuroradiological findings, constituents of cerebrospinal fluid (CSF), surgical treatment, and outcome. After initial good recovery following tumour resection all patients deteriorated secondarily due to development of hydrocephalus which was not encountered in the first postoperative CT-scans. Incidence is 3.4% overall and is 8.3% if exclusively calculated for frontal gliomas but increases to 15.2% if specified for patients with ventricular entry during tumour resection. Development of hydrocephalus is suggested to be due to proteinic precipitation since analysis of CSF revealed marked elevation of proteins in all patients. Whereas shunting of mere hydrocephalus yields satisfactory results outcome in cases of multiloculated hydrocephalus necessitating placement of multiple catheters is questionable. Development of hydrocephalus after resection of malignant gliomas is not rare. It should be considered in patients with delayed deterioration after initial improvement. Outcome in relation to hydrocephalus is favourable in cases of mere communicating hydrocephalus, occurrence of multiloculated hydrocephalus, however, heralds a poor prognosis.

Ventricular entry during resection of malignant gliomas: effect on intracranial cerebrospinal fluid tumor dissemination

The ventricular system is not infrequently entered during the course of maximum cytoreductive surgery for high-grade supratentorial gliomas. It is unclear if ventricular entry during surgery and/or proximity of the tumor to the ventricular system affects cerebrospinal fluid (CSF) tumor dissemination or the patients' overall survival rate. The authors retrospectively reviewed hospital records and neuroradiological studies of 51 patients operated on at the University of Washington between 1987 and 1991. Inclusion in this study necessitated a pathological diagnosis of malignant glioma and the availability of preoperative and postoperative computerized tomography scans or magnetic resonance images. Patients were excluded from the study if they had radiographic evidence of ventricular entry or CSF tumor dissemination prior to referral to the authors' institution. The index operation was defined as the first operation at the University of Washington or (in those patients with ventricular entry) the operation in which the ventricle was entered. Patients were followed until time of death or, in the case of survivors, until February, 1992. The effect of both ventricular entry and the proximity of the tumor to the ventricular system on CSF tumor dissemination and survival rate was assessed using statistical survival methodology. There was no significant difference in time from diagnosis to the index operation between groups compared (Mann-Whitney U-test, p > 0.40). Cerebrospinal fluid dissemination was radiographically documented in 18 patients (35%) following the index operation. This occurrence was not significantly influenced by either ventricular entry during surgery (Mantel-Cox test, p = 0.13), the proximity of the tumor to the ventricular system (p = 0.63), or these two variables combined (p = 0.28). Survival rate following the index operation was not significantly affected by ventricular entry (p = 0.66), proximity of the tumor to the ventricular system (p = 0.61), or these two variable considered in combination (p = 0.44). However, survival rate was significantly decreased once CSF tumor dissemination had occurred (Cox model, p = 0.03).

A new catheter design for use in patients with critical aortic stenosis.

A new catheter that facilitates catheterization in patients with severe aortic stenosis is described. The catheter design is capable of high-pressure injections for left ventriculography, but it maintains maneuverability and has an end hole for use with a guide wire in traversing tightly stenotic valves. Experience with this catheter in 23 patients confirmed that good-quality ventriculograms are obtained after left ventricular entry. Twenty-two of 23 patients with aortic stenosis were studied entirely with this catheter; in only one case were attempts to cross the valve unsuccessful, both with this and other catheters. In conclusion, this new catheter is recommended for routine use in patients with suspected severe aortic stenosis.

Isotopic Cisternography in Tuberculous Meningitis of Childhood

The changes in the CSF circulation and absorption are valuable in the diagnosis and management of tuberculous meningitis. We describe the isotopic cisternographic analysis of 45 children with tuberculous meningitis and 30 children with purulent meningitis. The cisternographic patterns of tuberculous meningitis consist of (1) obliteration of CSF space at the level of basal cisterns or cisterna Sylvii and (2) ventricular entry of radiopharmaceutical without clearing by 24 hours (communicating hydrocephalus). None of the patients with a definite diagnosis of tuberculous meningitis demonstrated a normal CSF flow pattern. Thirty patients with purulent meningitis underwent isotopic cisternography. Sixteen of 30 patients demonstrated a normal CSF flow pattern, 3 had mild hydrocephalus, 6 had obliteration of the subarachnoid space at the level of cisterna Sylvii at either side, 3 had delay of CSF flow, and 2 had abnormal CSF collection due to a posttraumatic dura defect.

Pseudo Subaortic Stenosis — A Catheter‐Induced Artifact

Three cases are reported of valvular aortic stenosis in which artifactual subvalvular chambers were recorded on pressure tracings. The pressure tracings were obtained during withdrawal of multiholed catheters from the left ventricle to the aortic root. Several recent reports have described the coexistence of valvular and subvalvular aortic stenosis. The cases reported here re-emphasize that a multiholed catheter, which is the type commonly used for retrograde left ventricular entry in a patient with valvular aortic stenosis, is unsatisfactory for the detection of coexisting subvalvular obstruction.

Rhinorrhea, ventricular radiopharmaceutical stasis and communicating hydrocephalus: evaluation by serial cisternography.

Spontaneous cerebrospinal fluid rhinorrhea has been known to occur in association with hydrocephalus. The specific pathophysiology which results in a potential communication between the cerebrospinal fluid space (subarachnoid space) and the nasopharynx is unknown. The relationship of CSF movement and rhinorrhea was evaluated in ten random source mongrel dogs. These data suggest that spontaneous CSF rhinorrhea may occur during the early developmental phase of communicating hydrocephalus in dogs. At this time radiopharmaceutical movement showed ventricular entry and clearing. When the lateral ventricles enlarged, ventricular radiopharmaceutical stasis was seen and the rhinorrhea disappeared. This suggests that CSF rkinorrhea may act as a compensatory mechanism which partially protects the CSF compartment to withstand the extra CSF during the early development of communicating hydrocephalus.

The Biliary and Urinary Excretion of Sodium Tyropanoate and Sodium Ipodate in Dogs: Pharmacokinetics, Influence of Bile Salts and Choleretic Effects with Comparison to Iopanoic Acid

The biliary and urinary excretion of sodium tyropanoate (Bilopaque) and sodium ipodate (Oragrafin) were studied in unanesthetized bile-fistula dogs using stepwise, increasing, intravenous infusions of the contrast materials. A constant intravenous infusion of sodium taurocholate was administered at the rate of either 0.5 or 2.0 mu moles per min per kg throughout each experiment. The biliary excretion of sodium tyropanoate or sodium ipodate was not effected by the rate of sodium taurocholate infusion. The maximum rate of biliary excretion of sodium ipodate was significantly greater than that of sodium tyropanoate with the low taurocholate infusion, but there was no significant difference between the two with the high taurocholate infusion. With the low taurocholate infusion the maximum biliary excretion rate of sodium tyropanoate (0.956 mu moles per min per kg) and sodium ipodate (1.472 mu moles per min per kg) were significantly greater than the maximum biliary excretion of iopanoic acid (Telepaque) (0.671 mu moles per min per kg). With the high taurocholate infusion the maximum biliary excretion rates of the three contrast agents were not statistically different. Both sodium tyropanoate and sodium ipodate produced an increase in canalicular bile flow (8-11 ml per millimole). These data suggest that in clinical cholecystography sodium tyropanoate and sodium ipodate are not excreted in bile more rapidly than iopanoic acid, except when the rate of biliary excretion of bile salts is low; that is, except in patients who are fasting or those who are on a fat-free diet.