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Biomedical subjects

T B Kinney

Publications and source records attributed to T B Kinney.

At least 19 recordsLinked to original sources
PubMed2001

Fatal paradoxic embolism occurring during IVC filter insertion in a patient with chronic pulmonary thromboembolic disease.

A patient diagnosed with chronic thromboembolic disease experienced a fatal intraprocedural paradoxic embolism during inferior vena cava (IVC) filter insertion. The frequency of patent intra-atrial shunts in patients with chronic thromboembolic disease is surprisingly high, occurring in approximately 29.5% of patients with chronic thromboembolic disease. Prevention of embolic events during venous interventions in such cases requires that the operator recognize that central shunts may be present and strictly adhere to meticulous technique during IVC filter insertion.

Aged↗
PubMed2001

Direct US-guided puncture of the innominate veins for central venous access.

Maintenance of functioning venous access is recognized as the Achilles heel of long-term hemodialysis treatment. In patients who require catheter-directed hemodialysis, the internal jugular veins are recognized as the optimal veins for insertion of dialysis catheters. When these sites are no longer available, alternative venous access sites are required. The authors describe two hemodialysis patients with limited access sites in whom hemodialysis catheters were successfully inserted directly into the innominate veins with use of ultrasound-guided punctures.

Adult↗
PubMed2001

Value of three-dimensional US for optimizing guidance for ablating focal liver tumors.

PURPOSE: To determine if three-dimensional ultrasound (3D US), by nature of its ability to simultaneously evaluate structures in three orthogonal planes and to study relationships of devices to tumor(s) and surrounding anatomic structures from any desired orientation, adds significant additional information to real-time 2D US used for placement of devices for ablation of focal liver tumors. MATERIALS AND METHODS: Sixteen patients underwent focal ablation of 23 liver tumors during two intraoperative cryoablation (CA) procedures, three intraoperative radiofrequency ablation (RFA) procedures, 11 percutaneous ethanol injections (PEI) procedures, and six percutaneous RFA procedures. After satisfactory placement of the ablative device(s) with 2D US guidance, 3D US was used to reevaluate adequacy to device position. Information added by 3D US and resultant alterations in device deployment were tabulated. RESULTS: 3D US added information in 20 of 22 (91%) procedures and caused the operator to readjust the number or position of ablative devices in 10 of 22 (45%) of procedures. Specifically, 3D US improved visualization and confident localization of devices in 13 of 22 (59%) procedures, detected unacceptable device placement in 10 of 22 (45%), and determined that 2D US had incorrectly predicted device orientation to a tumor in three of 22 (14%). CONCLUSIONS: Compared to conventional 2D US, 3D US provides additional relationship information for improved placement and optimal distribution of ablative agents for treatment of focal liver malignancy.

Adult↗
PubMed2001

Integral role of interventional radiology in the development of a pediatric liver transplantation program.

The aim of this study was to examine the role of interventional radiology (IR) in the pretransplant evaluation of potential living-related liver transplantation (LRLT) donors and in the post-transplant management of pediatric liver transplant recipients. Medical records and procedural reports were reviewed of 12 potential donors and five recipients for left lateral segment liver transplants. Procedures performed by the IR Division, clinical indications, and complications were tabulated. Retrospective calculation of radiation exposure to the skin and gonads of the donors and recipients were made. Three-dimensional ultrasound (3D US) was used in all 12 potential donors to screen for the donor with the most appropriately sized left lateral segment. The four optimal donor candidates underwent contrast angiography in order to measure the diameter and screen for variant arterial supply to the left lateral segment. Pretransplantation, one recipient underwent mesenteric angiography with indirect portography to confirm thrombosis of the portal vein and to prove patency of the splenomesenteric venous confluence. Three children underwent LRLT and two children received split livers from cadaveric donors. Thirty-two IR procedures were performed after transplantation (Tx) in the four transplant survivors (one child died following Tx). These IR procedures included: ultrasound-guided percutaneous liver biopsy to evaluate the pathologic cause of liver dysfunction (seven); placement of nasal jejunal feeding tubes (three) or a peripherally inserted central catheter (four) for nutritional and pharmacologic support; large-volume diagnostic and therapeutic paracentesis (two) and thoracentesis (one); percutaneous catheter drainage of symptomatic large pleural effusions (two), large-volume chylous ascites (one) (with later drain removal [one]), and a large biloma (one); percutaneous biliary drain placement (three), biliary drain replacement (two), and balloon cholangioplasty (four) to relieve obstructive jaundice from biliary enteric anatomic strictures; and mesenteric arteriography (one) for suspected thrombosis of the hepatic artery. No complications occurred. Mean skin and gonadal radiation doses were 193 mGy and 27 mGy, respectively, for donors, and 164 mGy and 60 mGy, respectively, for recipients. Even in a program such as this, with a limited series of pediatric liver Txs, it is apparent that IR plays an integral role in optimizing the clinical outcome and use of resources. Specific benefits included: selection of optimal donors; accurate mapping of the donor and occasionally recipient hepatic vasculature; and, most importantly, providing relatively safe minimally invasive procedures for nutritional support and diagnosis and management of untoward events after Tx. When possible, ultrasound guidance should be used to avoid excessive cumulative fluoroscopic exposure to recipients.

Adolescent↗
PubMed2000

Pulmonary embolism from pulse-spray pharmacomechanical thrombolysis of clotted hemodialysis grafts: urokinase versus heparinized saline.

PURPOSE: To compare the frequency and extent of pulmonary embolism (PE) occurring during pulse-spray pharmacomechanical thrombolysis (PSPMT) of clotted hemodialysis grafts with use of either urokinase (UK) or heparinized saline (HS). Postintervention primary patency and complication rates were compared for each method of thrombolysis. METHODS AND MATERIALS: Twenty-seven patients were enrolled in this prospective, randomized, double-blind study evaluating PE with two PSPMT agents. The doses of heparin were similar between groups. The only variable was that one group of patients received UK and the other received HS. In two cases, the venous anastomosis could not be crossed. Eleven patients were treated with UK and 14 with HS. Nuclear medicine perfusion lung scans were performed before treatment and after graft declotting procedures. Lung perfusion was quantified to 10% of a pulmonary segment (0 = normal perfusion, 1 = segmental perfusion defect), with nine segments counted for each lung. RESULTS: Baseline nuclear medicine perfusion lung scan results were abnormal (> or = 20% segmental perfusion defect) in 19 patients (70.4%). New PE (one or more pulmonary segments) occurred in two patients treated with UK (18.2%) and nine patients treated with HS (64.3%; P = .04). All cases of PE were asymptomatic. Quantitative global pulmonary perfusion analyses revealed that treatment with UK improved flow to 0.2 +/- 2.0 pulmonary segments, whereas treatment with HS decreased perfusion to 1.0 +/- 1.7 segments (P = .16, NS). Although postintervention primary patency rates were similar according to life-table analysis (P = .76, NS), complication rates were higher with use of HS (n = 4, 28.6%) than with use of UK (n = 2, 18.2%) (P = .6, NS). CONCLUSIONS: All PE were asymptomatic during PSPMT, but treatment with UK reduced the rate of PE and tended to result in smaller defects in lung scan results. Most patients undergoing hemodialysis have abnormal baseline perfusion scan results, but PSPMT with UK improved many of them. The postintervention primary patency rates were similar between groups, but complications were more frequent after treatment with HS.

Adult↗
PubMed2000

Adjunctive 3D US for achieving portal vein access during transjugular intrahepatic portosystemic shunt procedures.

PURPOSE: To evaluate the usefulness of information provided by three-dimensional ultrasound (3D US) and to determine whether 3D US decreased the number of passes required to obtain portal vein (PV) access during creation of transjugular intrahepatic portosystemic shunts (TIPS). MATERIALS AND METHODS: Intermittent 3D US volume acquisitions were obtained during creation of TIPS in 20 patients. Useful information provided by 3D US was tabulated. The number of passes required to achieve PV access was recorded and results were compared retrospectively to 25 patients who underwent TIPS without 3D US. RESULTS: 3D US documented that the operator's opinion of which hepatic vein had been selected was incorrect in nine patients (45%), detected unfavorable PV anatomy that required modification of equipment or technique in seven patients (35%), permitted estimation of the trajectory required to access the targeted PV in all patients (100%), assisted in selecting the optimal point along the hepatic vein for origination of the needle pass in 11 patients (55%), allowed avoidance of a large hepatocellular carcinoma in one patient (5%), and confirmed that access into the main PV was intrahepatic in four patients (20%). The mean number of needle passes decreased from 10.4 in the historic control group to 4.6 in the 3D US group (P = .0001). CONCLUSION: 3D US provided imaging information that detected technical errors and altered anatomy, and provided positional and directional information to significantly improve needle pass efficiency.

Adult↗
PubMed2000

Adjunctive 3D US for achieving portal vein access during transjugular intrahepatic portosystemic shunt procedures.

PURPOSE: To evaluate the usefulness of information provided by three-dimensional ultrasound (3D US) and to determine whether 3D US decreased the number of passes required to obtain portal vein (PV) access during creation of transjugular intrahepatic portosystemic shunts (TIPS). MATERIALS AND METHODS: Intermittent 3D US volume acquisitions were obtained during creation of TIPS in 20 patients. Useful information provided by 3D US was tabulated. The number of passes required to achieve PV access was recorded and results were compared retrospectively to 25 patients who underwent TIPS without 3D US. RESULTS: 3D US documented that the operator's opinion of which hepatic vein had been selected was incorrect in nine patients (45%), detected unfavorable PV anatomy that required modification of equipment or technique in seven patients (35%), permitted estimation of the trajectory required to access the targeted PV in all patients (100%), assisted in selecting the optimal point along the hepatic vein for origination of the needle pass in 11 patients (55%), allowed avoidance of a large hepatocellular carcinoma in one patient (5%), and confirmed that access into the main PV was intrahepatic in four patients (20%). The mean number of needle passes decreased from 10.4 in the historic control group to 4.6 in the 3D US group (P = .0001). CONCLUSION: 3D US provided imaging information that detected technical errors and altered anatomy, and provided positional and directional information to significantly improve needle pass efficiency.

Adult↗
PubMed2000

Early rethrombosis of clotted hemodialysis grafts: graft salvage achieved with an aggressive approach.

OBJECTIVE: The purpose of this study was to assess the efficacy of repeated pulsed spray pharmacomechanical thrombolysis for salvage of early rethrombosis of hemodialysis grafts and to identify factors that predict successful outcome. MATERIALS AND METHODS: Thirty-four patients with initial successful thrombolysis were referred for repeated thrombolysis because of early rethrombosis. Repeated thrombolysis occurred within 1 month of initial thrombolysis. Technical success and patency rates were calculated. Causes of graft thrombosis and procedural modifications were analyzed. RESULTS: The 39 rethrombosed grafts were successfully treated using pharmacomechanical thrombolysis, and patients underwent subsequent hemodialysis. The underlying flow-limiting stenoses were treated with balloon angioplasty using a larger balloon (41%), a same-size angioplasty balloon (18%), stent placement (15%), or increased anticoagulation (5%). A new stenosis location was discovered in 18%. Mean primary patency was 80.9 days (2.6 months) and secondary patency was 235.4 days (7.8 months). With life table analysis, 1-, 3-, 6-, and 12-month primary patency rates were 72%, 31%, 23%, and 15%, and secondary patency rates were 77%, 62%, 51%, and 31%, respectively. Graft patency rates in our study were compared with our institutional historic graft patency rates, with no significant difference noted (p = 0.76). No major procedural complications occurred. CONCLUSION: Adequate technical success and patency rates for pharmacomechanical thrombolysis occur even for hemodialysis grafts that rethrombose within 1 month. After thrombolysis, aggressive search for and treatment of additional stenoses are warranted.

Blood Vessel Prosthesis↗
PubMed1996

Intraarterial pressure measurements during angiographic evaluation of peripheral vascular disease: techniques, interpretation, applications, and limitations.

Many operative and percutaneous procedures are available for the treatment of occlusive disease involving the lower-extremity arterial system. Peripheral vascular disease involving the aorta and lower-extremity vessels usually is attributable to atherosclerosis. The lower-extremity arterial supply is divided segmentally into the inflow (aortoiliac) and outflow (femoropopliteal and tibioperoneal) vessels. Given the length of the lower-extremity vascular system, the propensity for multifocal disease, and the possibility of a nonvascular cause for a patient's symptoms, both localization of disease in arterial segments and determination of the hemodynamic impact of diseased sites are important for judicious treatment planning. This review focuses on the use of intraarterial pressure measurement as an adjunct to angiography and intravascular intervention in evaluating the significance of arterial occlusive disease in lower-extremity arteries.

Angiography↗
PubMed1995

A theoretical model using mechanical principles to quantify the physical principles of balloon dilatation.

RATIONALE AND OBJECTIVES: Balloon dilatation is a mechanical form of controlled injury used to alleviate vascular stenoses. Several factors influence successful angioplasty. Few mechanical models exist to illustrate the physical principles of balloon dilatation. METHODS: We used mechanical analysis of membrane stresses, along with Laplace's law, to determine a relation between balloon inflation and dilating pressures exerted by balloons in stenoses of varying severity, length, and eccentricity. The balloons were assumed to be perfectly inelastic and flexible. We also examined the resultant stresses in the lesion wall of concentric and eccentric stenoses from exertion of dilating pressures. RESULTS: Dilating pressures depend directly on maximal balloon inflation pressure and balloon diameter. Short, focal stenoses experience greater dilating pressures, which often are several multiples of the inflation pressure, than similarly narrowed longer lesions. CONCLUSION: Dilating pressures depend on inflation pressure, balloon diameter, and lesion severity.

Angioplasty, Balloon↗
PubMed1993

Fine-needle biopsy: prospective comparison of aspiration versus nonaspiration techniques in the abdomen.

A prospective study was designed to compare the aspiration (suction method) and nonaspiration (nonsuction method) techniques of fine-needle biopsy (FNB) in 50 consecutive patients with abdominal pathologic conditions. Sites of biopsy included liver (n = 24), retroperitoneum (n = 9), adrenal gland (n = 5), pancreas (n = 4), omentum (n = 4), and miscellaneous sites (n = 4). Aspiration and nonaspiration FNBs were performed in each lesion with 22-gauge needles, and results were interpreted by a single cytopathologist. Cytologic specimens obtained with each technique were analyzed for diagnostic accuracy, total number of cell clusters per biopsy (graded 0-10, 10-20, 20-30, and > 30), presence of crush artifact, and amount of blood present (graded from 0 to +3). No significant differences were seen between the aspiration and nonaspiration techniques with regard to number of cell clusters per biopsy (44 of 50 specimens vs 42 of 50) (P < .0003), amount of blood present (grade 2.3 vs 2.2) (P < .0003), and amount of crush artifact. The positive predictive value for the aspiration technique was 91.5% versus 74% for the nonaspiration technique. The aspiration technique of FNB appears superior to the nonaspiration technique in the abdomen.

Abdomen↗
PubMed1991

Optimizing myocardial hypothermia: I. Temperature probe design and clinical inferences.

Myocardial hypothermia is an essential component of myocardial preservation for most cardiac operations. Because of multiple causes of rewarming, it is necessary to monitor temperatures at specific sites (right and left ventricular epicardium and endocardium or cavity). Thus, plastic temperature probes have been designed and fabricated to facilitate temperature monitoring at these sites. Using a bare thermocouple as a standard, in vitro comparison of metallic probes and plastic probes revealed differences of 4.0 degrees +/- 0.9 degrees C and 0.7 degrees +/- 0.6 degrees C, respectively (p less than 0.005). Consequently, metallic probes do not have sufficient accuracy to detect transmural temperature gradients because of "stem effect." Using the plastic probes to evaluate temperature changes in porcine hearts after cardioplegia-induced hypothermia revealed a temperature rise of 1 degree C/min at all sites if control of systemic and venous return and local myocardial cooling are not provided. The use of temperature monitoring at multiple sites permits identification and prevention of various causes of myocardial rewarming and is facilitated by the use of plastic probes described herein which contain dual thermocouples.

Animals↗
PubMed1991

Optimizing myocardial hypothermia: II. Cooling jacket modifications and clinical results.

After induction of myocardial hypothermia by cold cardioplegic solution, myocardial rewarming occurs at 0.5 degrees to 1.0 degrees C/min. In addition to preventing myocardial rewarming from systemic and pulmonary venous return, continuous cooling of the myocardial surface must be provided. Modifications of a previously reported cooling jacket are described. These modifications include decreased width and thickness of the metal skeleton for easier application and increased malleability, respectively. Also, the double-row flow channel markedly minimizes obstruction of flow secondary to kinking and allows inlet and outlet lines to attach at adjacent points of the jacket thus minimizing obstruction of the operative field. The effectiveness of the jacket in 36 patients undergoing valve replacement and 19 patients having pulmonary thromboendarterectomy was evaluated by measurement of myocardial temperatures at multiple sites throughout aortic cross-clamping. Temperatures at all sites were maintained at 12 degrees C or less. Temperatures measured in phrenic nerve pedicles ranged from 25 degrees to 27 degrees C. During cooling, heat removal by the jacket was 330 calories/min. During maintenance of myocardial hypothermia, heat flow was 190 calories/min. Modifications of a cooling jacket facilitate usability and an array of sizes enhances applicability.

Body Temperature↗