Grant W. Stoneham

Doppler studies evaluating the effect of a physical therapy screening protocol on vertebral artery blood flow

General and isolated cervical positional tests are used to screen for potential vertebro-basilar insufficiency (VBI). There is limited research evaluating vertebral artery blood flow in these positions to justify the rationale of progressive mechanical stress occurring to the arteries. The purpose of the study was to determine vertebral artery blood flow in six cervical positions used in clinical practice. A comprehensive cervical assessment was conducted on 22 men and women (mean age 35) with no known vascular pathology. Vertebral artery peak systolic (PS), end diastolic (ED) flow rates and resistive index (RI) were measured using duplex colour Doppler sonography (sampling at C3-C5) in neutral, rotation, extension, combined rotation-extension, combined rotation-extension-traction, deKelyns position and a C1-C2 pre-manipulative hold. Results showed there was a significant decrease in PS and ED in the contra-lateral artery during the pre-manipulative hold, and a decrease in ED in the contra-lateral artery during rotation. There was no effect of age, gender or mobility restriction on these blood flow changes. The pre-manipulative hold had the greatest response with 34% of the arteries demonstrating a complete cessation of ED flow. In conclusion the pre-manipulative hold and rotation created the greatest mechanical stress to the contra-lateral vertebral artery. These two positions may be useful screening positions to identify individuals at risk for VBI due to inadequate collateral blood flow.

Temporary Inferior Vena Cava Filters: In Vitro Comparison with Permanent IVC Filters

PURPOSE An in vitro comparison of clot-trapping abilities of permanent and temporary inferior vena cava (IVC) filters. MATERIALS AND METHODS A flow model was used to simulate the IVC. Two permanent IVC filters, the titanium Greenfield and LG-Medical (LGM), were compared with two temporary filters, the Filcard International and Gunther. Clot sizes used were 2.5 x 2.5 mm, 2.5 x 5 mm, 5 x 5 mm, 5 x 10 mm, and 5 x 20 mm. Individual clots were presented to the filters with the simulated IVC in a horizontal or vertical orientation. Clot-trapping dynamics and pressure gradient changes during the injection of multiple, sequential clots were also examined. RESULTS As clot size diminished, all filters trapped fewer clots; however, the temporary filters trapped more small clots than the permanent filters. Very little difference was observed in clot-trapping abilities among the filters for clots of 5 x 10 mm or greater. In the horizontal orientation, the permanent filters trapped 38% of all clots delivered, while the temporary filters trapped 73%, chi 2 = 24.8 (P < .001). In the vertical orientation, the overall clot-trapping abilities of the filters improved, with the permanent filters trapping 73% of all clots delivered, while the temporary filters trapped 95%, chi 2 = 18 (P < .001). During trapping of multiple clots, the temporary filters allowed fewer clots to pass. CONCLUSION The temporary filters performed better than the permanent filters in both individual clot-trapping orientations. During multiple clot-trapping experiments, fewer clots were allowed to pass by the temporary filters. The temporary filters demonstrated the ability to capture clots both inside and outside the wire struts.

Synovial Chondromatosis and Chondrosarcoma: A Diagnostic Dilemma

Purpose: The progression of synovial chondromatosis to chondrosarcoma is very rare. Distinction between these two entities may be difficult on histology alone, and should be based on clinical, radiographic and microscopic evidence. Immunohistochemical markers that would facilitate differentiation between synovial chondromatosis and chondrosarcoma are currently being investigated. Patients: We describe the cases of two patients who presented with synovial chondromatosis and progression to synovial chondrosarcoma during periods of 7 and 11 years. Several biopsies and resected specimens demonstrated synovial chondromatosis before a diagnosis of chondrosarcoma was made. Method: We have examined five markers (Bcl2, Ki67, p27, p16, and p53) in all specimens from these cases, as well as known cases of chondromatosis and chondrosarcoma for control purposes. Results: We found increased expression of Bcl2 in benign chondromatosis compared to synovial or central chondrosarcomas. Discussion: Distinction between chondromatosis and its progression to low grade chondrosarcoma is difficult at histological level, and must involve incorporation of clinical and radiographical data. Although preliminary, our study suggests that reduced or absent expression of Bcl2 is associated withmalignant transformation of chondromatosis.

Percutaneous subclavian artery stent-graft placement following failed ultrasound guided subclavian venous access

BackgroundUltrasound guidance for central and peripheral venous access has been proven to improve success rates and reduce complications of venous cannulation. Appropriately trained and experienced operators add significantly to diminished patient morbidity related to venous access procedures. We discuss a patient who required an arterial stent-graft to prevent arterial hemorrhage following inadvertent cannulation of the proximal, ventral, right subclavian artery related to unsuccessful ultrasound guided access of the subclavian vein.Case presentationDuring pre-operative preparation for aortic valve replacement and aorto-coronary bypass surgery an anesthetist attempted ultrasound guided venous access. The ultrasound guided attempt to access the right jugular vein failed and the ultrasound guided attempt at accessing the subclavian vein resulted in inappropriate placement of an 8.5 F sheath in the arterial system. Following angiographic imaging and specialist consultations, an arterial stent-graft was deployed in the right subclavian artery rather than perform an extensive anterior chest wall resection and dissection to extract the arterial sheath. The patient tolerated the procedure, without complication, despite occlusion of the right internal mammary artery and the right vertebral artery. There were no neurologic sequelae. There was no evidence of hemorrhage after subclavian artery sheath extraction and stent-graft implantation.ConclusionThe attempted ultrasound guided puncture of the subclavian vein resulted in placement of an 8.5 F subclavian artery catheter. Entry of the catheter into the proximal subclavian artery beneath the medial clavicle, the medial first rib and the manubrium suggests that the operator, most likely, did not directly visualize the puncture needle enter the vessel with the ultrasound. The bones of the anterior chest impede the ultrasound beam and the vessels in this area would not be visible to ultrasound imaging. Appropriate training and supervised experience in ultrasound guided venous access coupled with quality ultrasound equipment would most likely have significantly diminished the likelihood of this complication. The potential for significant patient morbidity, and possible mortality, was prevented by implantation of an arterial stent-graft.

Radiology-Implanted Arm Ports: A Review of the Literature

Background Insertion of totally implanted venous access devices; that is, port systems, in the forearm is an option for long-term venous access. To better understand the radiology literature reported for this anatomic location, we performed a search for, and an analysis of, previous publications related to forearm implantation of these devices by interventional radiology department personnel.

Comparison of post-operative lordosis with the PEEK cage and the cervical plate.

OBJECTIVE The maintenance of post-operative lordosis has been shown to be a key factor in decreasing adjacent level disc stress. Previous studies of the PEEK (polyether ketone) cage have used intervertebral bony fusion as the primary measure of surgical success; however, little is known about its effects on spinal curvature. Our objective was to compare the PEEK cage to the cervical plate with respect to the maintenance of cervical lordosis at one year. Secondary outcomes included fusion and complication rates. METHODS We performed a retrospective study of patients who underwent ACDF (anterior cervical discectomy and fusion) by two different methods; 13 patients were treated with the PEEK cage, and 22 with allograft and plating. RESULTS Patient and treatment characteristics were similar in both groups. Average global lordotic curvature (C2-C7) was increased by 1.7 degrees for the PEEK cage and decreased by 1.6 degrees for the plate after an average follow-up of 12.46 and 14.95 months, respectively. Regional lordosis for the PEEK cage and plate was decreased by 2.5 and 2.1 degrees, respectively for the same time period. These differences did not achieve statistical significance. Bony fusion was observed in all patients. One patient in each group developed persistent mild dysphagia. CONCLUSIONS The PEEK cage is comparable to the anterior cervical plate in the maintenance of post-operative cervical lordosis.

Comparison of computed tomography 3-dimensional volumetric analysis of ventricular size to visual radiological assessment.

Objectives: Interpretation of ventricular volume on computed tomography scans of hydrocephalus patients is usually subjective. The objective of this study was to determine whether radiological assessment of interval change correlates better with an objective calculated volume change or with other objective 2-dimensional estimates of ventricle volume change. Methods/Sample: Ventricular volume, Evans ratio, and frontal and occipital Horn ratio were retrospectively assessed on 95 pairs of scans from patients with a ventriculoperitoneal shunt. To determine ventricle volume, all voxels of cerebrospinal fluid density were isolated on a 3-dimensional reconstructed computed tomography scan. Voxels of fluid density contiguous with one another in the ventricular system were isolated. Radiological assessments of interval change were divided into 5 groups based on reported findings in the radiology report. The 95% mean confidence intervals were developed for changes in the measured parameters, given a particular radiological assessment. Multinomial regression was subsequently performed to determine which parameter was most closely correlated with the radiological assessment. Results: Significant overlap was found in the confidence intervals for objectively calculated volume change between the different categories of radiological assessment. The frontal and occipital Horn ratio had the most consistent correlation with the radiological assessment, followed by the Evans ratio. Objectively calculated volume change correlated poorly with radiological assessment. Conclusions: Radiological interpretation does not correlate well with objectively calculated volume changes, but correlates better with other parameters that approximate volume and are likely used to visually evaluate interval change. We recommend that ventricle volume be objectively measured to increase consistency between radiological interpretation and actual interval changes.

Pneumoperitoneum Post-Fluoroscopic Percutaneous Gastrojejunostomy Insertion: Computed Tomography and Clinical Evaluation

Introduction To assess the incidence and clinical significance of pneumoperitoneum after radiologic percutaneous gastrojejunostomy (PGJ) tube insertion. Methods Sixteen subjects were prospectively assessed after imaging-guided PGJ tube insertion to discern the incidence of pneumoperitoneum related to specific clinical signs and symptoms. Computed tomography of the abdomen and the pelvis was performed immediately after PGJ insertion. A clinical evaluation, including history, general and abdominal physical examination, temperature, complete blood cell count, abdominal pain, and abdominal tension, was performed on days 1 and 3, and at the discretion of the nutritional support team on day 7 after PGJ insertion. Results Fifteen of the 16 subjects demonstrated imaging findings of pneumoperitoneum after the PGJ-tube insertion. Only a small amount of pneumoperitoneum was demonstrated in 10 of the subjects, whereas a large volume of gas was detected in 2 of the subjects. The only altered clinical findings encountered were increased white blood cell count and fever. These abnormal clinical data were most frequently seen immediately after feeding-tube placement. Discussion Pneumoperitoneum was a common finding after PGJ-tube placement in our study population. There were no statistically significant abnormal clinical parameters, in the presence or absence of pneumoperitoneum, for any of the subjects after PGJ-tube insertion. Conservative management of pneumoperitoneum after PGJ is warranted.

Satisfaction and Quality of Life Related to Chemotherapy With an Arm Port: A Pilot Study

Purpose Placement of arm ports, or totally implanted venous access devices, is a common practice in our interventional radiology suite. We implant a miniaturized port in the upper arm for the provision of long-term chemotherapy. We hypothesized that there was general satisfaction with these arm ports and they have a minimal negative impact on quality of life. In this study we aimed to assess our hypotheses. Methods We surveyed subjects, who having previously received an arm port for chemotherapy to treat a malignancy, attended the interventional room for its removal. The survey assessed the ports effect on lifestyle, the degree of device-related pain, the acceptance of the port, and the willingness to have another port in the future. Results Survey responses from 77 subjects were reviewed. On a scale of 1 (most negative) to 10 (most positive), respondents indicated that the port system was a very positive enhancement to their treatment (satisfaction = 9.2 ± 2.0 and positivity = 8.8 ± 2.2). The port had little impact on daily activities. The mean score for the likelihood of choosing to have another port placed if additional treatment was required was 9.1 ± 2.1. Discussion The arm port in this study did not negatively impact subject satisfaction and quality of life for this cohort. Most subjects rated the device utility highly and felt that the port was a positive enhancement to their treatment, one that they would possibly utilise again in future, if need be.

Answer to Case of the Month #161: Internal Hernia Through the Foramen of Winslow

A 77-year-old woman presented with a 1-week history of intermittent right upper quadrant pain. She had no nausea, vomiting, jaundice, or temporal relationship of the pain to eating. Her surgical history included a hysterectomy and appendectomy. On physical examination, her right upper quadrant was tender to palpation and percussion, but there was no guarding, rebound tenderness, or flank pain. Laboratory tests were normal. A supine abdominal radiograph (Figure 1) and computed tomographic imaging (Figures 2, 3) was obtained.