Biomedical subjects

Stephen T Kee

Publications and source records attributed to Stephen T Kee.

At least 19 recordsLinked to original sources

PubMed2006

Massive pulmonary embolus with hemodynamic compromise: therapeutic options.

Recent advances in pharmacotherapeutics and interventional techniques have resulted in resurgence in interest regarding the optimal means of management of hemodynamically significant pulmonary embolic disease. However, these various techniques have many associated disadvantages, and it is of paramount importance that the responsible physician has a detailed understanding of each of these so that the appropriate intervention be requested and performed. By way of background discussion and relevant cases in point, we consider each of these management options in turn, with particular reference to the advantages, disadvantages, and application of each.

Anticoagulants↗

PubMed2006

Retrieval of trapped Günther Tulip inferior vena cava filters: snare-over-guide wire loop technique.

The Günther Tulip inferior vena cava (IVC) filter is designed for transjugular retrieval with use of a sheath and snare device. This report describes a technique for removal of difficult-to-retrieve Günther Tulip IVC filters when the standard method fails. In a series of four patients, each with an IVC filter refractory to capture by snare alone, the use of a snare-over-guide wire loop technique succeeded in retrieving the filter in all cases.

Adult↗

PubMed2005

Treatment of hepatic venous outflow obstruction after piggyback liver transplantation.

PURPOSE: To evaluate retrospectively the endovascular management of hepatic venous outflow obstruction after piggyback orthotopic liver transplantation. MATERIALS AND METHODS: The study was performed with the approval and under the guidelines of the institutional review board and complied with the Health Insurance Portability and Accountability Act. Informed consent from patients was not required by the institutional review board for this retrospective study. From 1995 to 2003, 13 patients (eight male, five female), including 12 adults and one adolescent (age range, 14-67 years; median age, 52 years), underwent endovascular treatment of hepatic venous outflow obstruction after piggyback orthotopic liver transplantation. Patients gave informed consent for all procedures. Eleven patients received whole livers, and two received living-related donor right liver lobes. Four underwent repeat piggyback orthotopic liver transplantation prior to intervention. Primary stent placement was performed in 12 patients. One patient refused primary stent placement and chose venoplasty alone, but required a stent 5 months later. Short balloon-expandable stents (mean diameter, 14.6 mm +/- 1.1 [standard deviation]) were used to minimize jailing of branch vessels and to resist recoil. Pre- and post-procedural pressure gradients were measured. Follow-up included venography, cross-sectional imaging, and laboratory tests. The Wilcoxon signed rank test or the sign test was performed to compare pre- and post-procedural pressure gradients, body weights, and laboratory values. RESULTS: Technical success (pressure gradient < or = 3 mm Hg) was achieved in 13 of 13 patients, and clinical success, in 12 of 13. Mean pre- and post-procedural pressure gradients were 13.0 mm Hg +/- 1.4 and 0.8 mm Hg +/- 0.3. Mean interval from transplantation to intervention was 348 days +/- 159. Mean follow-up was 678 days (range, 16-2880 days). Technical success did not result in clinical improvement in one patient. Biopsy demonstrated severe hepatic necrosis, likely from prolonged venous congestion, and the patient required repeat transplantation. Only one patient required reintervention for stent migration, and no other complications occurred. No significant restenosis was encountered after stent placement. CONCLUSION: Hepatic venous outflow obstruction is an uncommon but potentially fatal complication of piggyback orthotopic liver transplantation. Endovascular treatment with balloon-expandable stents is effective, safe, and apparently durable.

Adolescent↗

PubMed2005

Truly hybrid X-ray/MR imaging: toward a streamlined clinical system.

RATIONALE AND OBJECTIVE: We have installed an improved X-ray/MR (XMR) truly hybrid system with higher imaging signal-to-noise ratio (SNR) and versatility than our first prototype. In our XMR design, a fixed anode X-ray fluoroscopy system is positioned between the two donut-shaped magnetic poles of a 0.5T GE Signa-SP magnet (SP-XMR). This paper describes the methods for increased compatibility between the upgraded x-ray and MR systems that have helped improve patient management. MATERIALS AND METHODS: A GE OEC 9800 system (GE OEC Salt Lake City, UT) was specially reconfigured for permitting X-ray fluoroscopy inside the interventional magnet. A higher power X-ray tube, a new permanent tube mounting system, automatic exposure control (AEC), remote controlled collimators, choice of multiple frame rates, DICOM image compatibility, magnetically shimmed X-ray detector, X-ray compatible MR coil, and better RF shielding are the highlights of the new system. A total of 23 clinical procedures have been conducted with SP-XMR guidance of which five were performed using the new system. RESULTS: The 70% increased power for fluoroscopy, and a new 6 times higher power single frame imaging mode, has improved imaging capability. The choice of multiple imaging frame rates, AEC, and collimator control allow reduction in X-ray exposure to the patient. The DICOM formatting has permitted easy transfer of clinical images over the hospital PACS network. The increased MR compatibility of the detector and the X-ray transparent MR coil has enabled faster switching between X-ray and MR imaging modes. CONCLUSION: The improvements introduced in our SP-XMR system have further streamlined X-ray/MR hybrid imaging. Additional clinical procedures could benefit from the new SP-XMR imaging.

Equipment Design↗

PubMed2005

Endovascular treatment of thoracic aortic aneurysms: results of the phase II multicenter trial of the GORE TAG thoracic endoprosthesis.

OBJECTIVE: A decade after the first report of descending thoracic aortic aneurysm (DTA) repair with endografts, a commercial device is yet to be approved in the United States. The GORE TAG endoprosthesis, an investigational nitinol-supported expanded polytetrafluoroethylene tube graft with diameters of 26 to 40 mm, is the first DTA device to enter phase II trials in the United States and has been used worldwide for a host of thoracic pathologies. METHODS: A multicenter prospective nonrandomized phase II study of the GORE TAG endoprosthesis was conducted at 17 sites. Enrollment was from September 1999 to May 2001. Preoperative workup included arteriography and spiral computed tomography scans of the chest, abdomen, and pelvis. Follow-up radiographs and computed tomography scans were obtained at 1, 6, and 12 months and yearly thereafter. RESULTS: A total of 139 (98%) of 142 patients had a successful implantation of the device. Inadequate arterial access was responsible for the 3 failures. The mean DTA size was 64.1 +/- 15.4 mm. Men slightly outnumbered women (57.7%), with an average age of 71 years, and 88% of the patients were white. Ninety percent were American Society of Anesthesiologists category III or IV. One device was used in 44% of patients, and 56% required two or more devices to bridge the thoracic aorta. The left subclavian artery was covered in 28 patients, with planned carotid-subclavian transposition. The procedure time averaged 150 minutes, estimated blood loss averaged 506 mL, intensive care unit stay averaged 2.6 days, and hospital stay averaged 7.6 days. Within 30 days, 45 (32%) patients had at least 1 major adverse event: 5 (4%) experienced a stroke, 4 (3%) demonstrated temporary or permanent paraplegia, 20 (14%) experienced vascular trauma or thrombosis, and 2 (1.5%) died. Mean follow-up was 24.0 months. Four patients had aneurysm-related deaths. Three patients underwent endovascular revisions for endoleak. No ruptures have been reported. Twenty wire fractures have been identified in 19 patients; 18 (90%) of these occurred in the longitudinal spine, and only 1 patient required treatment. At 2 years, aneurysm-related and overall survival rates are 97% and 75%, respectively. CONCLUSIONS: The GORE TAG thoracic endoprosthesis provides a safe alternative for the treatment of DTAs, with low mortality, relatively low morbidity, and excellent 2-year freedom from aneurysm-related death. Longitudinal spine fractures have so far been associated with rare clinical events.

Adult↗

PubMed2005

MR-guided transjugular intrahepatic portosystemic shunt creation with use of a hybrid radiography/MR system.

PURPOSE: To evaluate the performance of a combined hybrid radiography/magnetic resonance (MR) unit to guide portal vein (PV) puncture during human transjugular intrahepatic portosystemic shunt (TIPS) creation. MATERIALS AND METHODS: Fourteen patients undergoing TIPS creation were studied during standard clinical applications. Patients were anesthetized and then positioned in an open MR unit containing a flat-panel radiographic fluoroscopic unit. With use of a combination of fluoroscopy and MR imaging, the PV was accessed and the TIPS procedure was performed. A noncovered nitinol stent or a covered stent-graft was placed in the TIPS tract. Number of punctures required, total procedure time, fluoroscopy time, procedural success rate, complications, and ultrasonographic and clinical follow-up were recorded. RESULTS: Clinical success was obtained in 13 of 14 patients. In one patient, extrahepatic puncture of the PV occurred, resulting in hemorrhage and requiring placement of a covered stent to control the bleeding. The mean number of punctures required to access the PV was 2.6 +/- 1.7, and the total procedure time was 2.5 hours +/- 0.6. Mean fluoroscopy time was 22.3 minutes +/- 5.5. Results of clinical and ultrasonographic follow-up compare favorably to previously published reports. CONCLUSION: TIPS creation with a combination hybrid radiography/MR unit is feasible and may reduce the number of needle passes required and radiation exposure, with similar overall outcomes compared with studies reported in the literature.

Alloys↗

PubMed2005

Primary interpretation of thoracic MDCT images using coronal reformations.

OBJECTIVE: The objective of this study was to evaluate the accuracy and efficiency of primary interpretation of thoracic MDCT using coronal reformations as compared with transverse images. SUBJECTS AND METHODS: Fifty patients (18 females, 32 males; age range, 15-93 years; mean age, 63.6 years) underwent 4-MDCT of the chest (detector width, 1 mm; beam pitch, 1.5). Contrast material was administered in 20 of the 50 patients. Coronal and transverse sections were reformatted into 5-mm-thick sections at 3.5-mm intervals. All available image and clinical data consensually reviewed by two thoracic radiologists served as the reference standard. Subsequently, three other thoracic radiologists independently evaluated reformatted coronal and transverse images at two separate review sessions. Each image set was assessed in 58 categories for abnormalities of the lungs, mediastinum, pleura, chest wall, diaphragm, abdomen, and skeleton. Interpretation times and number of images assessed were recorded. Sensitivity, specificity, and interobserver concordance were calculated. Differences in mean sensitivities and specificities were evaluated with Wilcoxon's signed rank test. RESULTS: The most common findings identified were pulmonary nodules (n = 73, transverse images; n = 72, coronal images) and emphysema (n = 45, transverse; n = 40, coronal). The mean detection sensitivity of all lesions was significantly (p = 0.001) lower on coronal (44% +/- 26% [SD]) than on transverse (51% +/- 22%) images, whereas the mean detection specificity was significantly (p = 0.005) higher (96% +/- 5% vs 95% +/- 6%, respectively). Reporting findings for significantly (p < 0.001) fewer coronal images (mean, 63.0 +/- 4.6 images) than transverse images (mean, 91.9 +/- 8.8 images) took significantly (p = 0.025) longer (mean, 263 +/- 56 sec vs 238 +/- 45 sec, respectively). CONCLUSION: Primary interpretation of thoracic MDCT is less sensitive and more time-consuming using 5-mm-thick coronal reformations as compared with transverse images.

Adolescent↗

PubMed2004

Chronic traumatic aneurysms of the descending thoracic aorta: mid-term results of endovascular repair using first and second-generation stent-grafts.

OBJECTIVE: Endovascular stent-graft repair holds promise for treating traumatic injuries of the descending thoracic aorta. The durability of this approach, however, remains unknown. The objective is to evaluate the mid-term results of stent-graft repair of chronic traumatic aneurysms of the descending thoracic aorta. METHODS: Between 1993 and 2000, endovascular repair of the descending thoracic aorta with first (custom-fabricated) and second-generation (commercial) stent-grafts was performed in 15 patients (mean age 54+/-13 years) at an average of 18+/-14 years after the injury. Because of comorbidities, 4 patients (27%) were judged not to be reasonable surgical candidates for conventional open surgical approach. Follow-up was 100% complete and averaged 55+/-29 months. RESULTS: Stent-graft deployment was successful in all without need for surgical conversion. One patient died early postoperatively. No neurologic complications occurred. Two patients had a primary endoleak, one of them was successfully treated before discharge. Actuarial survival estimates at 1 and 6 years were 93+/-6% and 85+/-10%. Actuarial freedom from reintervention on the descending thoracic aorta was 93+/-6% and 70+/-15% at 1 and 6 years, respectively. Actuarial freedom from treatment failure (a conservative, all-encompassing performance indicator including endoleak, device mechanical fault, reintervention, late aortic-related death, or sudden, unexplained late death) at 1 and 6 years was 87+/-8% and 51+/-15%. CONCLUSIONS: Stent-grafting is safe in selected patients with chronic traumatic aneurysms and associated with satisfactory-but not optimal-mid-term durability. Serial follow-up surveillance imaging is mandatory to detect late stent-graft complications. Younger, good risk patients should be offered conventional open operation, reserving stent-grafting for those who are at prohibitive operative risk or who have limited life expectancy.

Adult↗

PubMed2004

Midterm results of endovascular repair of descending thoracic aortic aneurysms with first-generation stent grafts.

OBJECTIVE: Five years after reporting our initial stent-graft repair of descending thoracic aortic aneurysms experience, we determined the 5- to 10-year results of stent-graft treatment and identified risk factors for adverse late outcomes. METHODS: Between 1992 and 1997, 103 patients (mean age 69 +/- 12 years) underwent repair using first-generation (custom-fabricated) stent grafts. Sixty-two patients (60%) were unsuitable candidates for conventional open surgical repair ("inoperable"). Follow-up was 100% complete (mean 4.5 +/- 2.5 years; maximum 10 years). Outcome variables included death and treatment failure (endoleak, aortic rupture, reintervention, and/or aortic-related or sudden death). RESULTS: Overall actuarial survival was 82% +/- 4%, 49% +/- 5%, and 27% +/- 6% at 1, 5, and 8 years. Survival in open surgical candidates was 93% +/- 4% and 78% +/- 6% and at 1 and 5 years compared with 74% +/- 6% and 31% +/- 6% in those deemed inoperable (P <.001). Independent risk factors for death were older age (hazard ratio = 1.1; P =.008), previous stroke (hazard ratio = 2.8; P =.003), and being designated an inoperable candidate (hazard ratio = 1.9; P =.04). Actuarial freedom from aortic reintervention and treatment failure at 8 years was 70% +/- 6% and 39% +/- 8%, respectively. Earlier operative year (hazard ratio = 1.2; P =.07), larger distal landing zone diameter (hazard ratio = 1.1; P =.001), and transposition of the left subclavian artery (hazard ratio = 3.3; P =.008) were determinants of treatment failure. CONCLUSIONS: Survival after aneurysm repair using crude, first-generation stent grafts was satisfactory in good operative candidates but bleak in the inoperable cohort, raising the question of whether asymptomatic patients should have even been treated. Late aortic complications were detected in many patients, reemphasizing the importance of serial imaging surveillance.

Aged↗

PubMed2004

Stent-graft repair of penetrating atherosclerotic ulcers in the descending thoracic aorta: mid-term results.

BACKGROUND: Localized aortic pathoanatomic abnormalities are good targets for endovascular stent-grafting but only short-term results have been reported. Our objective was to determine the effectiveness of endovascular stent-graft treatment of patients with descending thoracic atherosclerotic penetrating atherosclerotic ulcers (PAU) and to identify risk factors for treatment failure. METHODS: Between 1993 and 2000 endovascular repair of PAU with first-generation (custom-fabricated) and second-generation (commercial) stent-grafts was performed in 26 patients (mean age, 70 years), 6 (23%) of whom had rupture. Fourteen patients (54%) were not candidates for open surgical repair. Follow-up was 100% complete (average, 51 months; maximum, 114 months). Outcome variables considered in the multivariable analysis included death and treatment failure (composite end-point comprising early death, endoleak, stent-graft mechanical fault, late aortic event, reintervention, and aortic-related or sudden death). RESULTS: Three patients (12% +/- 7% [+/-70% confidence limits]) died within 30 days and 2 had an early type I endoleak. Primary success rate was 92%. Actuarial survival estimates at 1, 3, and 5 years were 85% +/- 8%, 76% +/- 8% and 70% +/- 10% respectively and actuarial freedom from treatment failure was 81% +/- 8%, 71% +/- 9% and 65% +/- 10%. Multivariable analyses identified previous cerebrovascular accident (hazard ratio [HR] 17.1, p = 0.02) and female sex (HR 7.4, p = 0.08) as independent risk factors for death. For treatment failure the predictors were increasing aortic diameter (HR 1.1 [per mm above the mean value], p = 0.01) and female sex (HR 5.5, p = 0.09). CONCLUSIONS: Endovascular stent-graft repair is effective but not curative treatment for selected, high surgical risk, elderly patients with a descending aortic PAU over the medium term. Assiduous serial follow-up imaging after stent-grafting is mandatory to detect late complications especially in those with a large aorta.

Aged↗

PubMed2004

Thrombolysis for lower extremity deep venous thrombosis.

Catheter-directed thrombolysis (CDT) has been proposed as an alternative mode of therapy to anticoagulation in patients with massive, symptomatic deep vein thrombosis of the extremity. The major goal of therapy is to rapidly restore venous blood flow, reduce the pain and edema of the extremity, preserve venous valve function, and reduce chronic symptoms related to chronic venous hypertension (postthrombotic syndrome). In patients with iliofemoral deep venous thrombosis (DVT) standard angiographic techniques are used to instrument a lower extremity vein (popliteal) and venography is performed followed by catheter-directed infusion of a plasminogen activator directly into the thrombus. Following lytic infusion, the interventionalist must evaluate the venous drainage to determine if there is an anatomic lesion that requires further endovascular treatment (eg, iliac vein compression syndrome). Posttreatment therapy usually consists of warfarin therapy and venous compression stockings for at least 3 to 6 months. The purpose of this article is to review the technical approach used in treating iliofemoral DVT and highlight the hurdles that face interventionalists in attempting to broaden this procedure to most types of lower extremity DVT.

Catheterization, Peripheral↗

PubMed2004

Percutaneous bypass: subintimal recanalization of peripheral occlusive disease with IVUS guided luminal re-entry.

Angioplasty of chronic total occlusions (CTOs) has lower technical success rates with longer procedure times and poorer outcomes. Subintimal recanalization remains limited by the lack of controlled re-entry into the true lumen of the target vessel. We report our experience using a commercially available catheter-based system equipped with an intravascular ultrasound scanner to achieve controlled true lumen re-entry in patients with peripheral CTOs. In a 4-month period, 6 patients with lower extremity (LE) ischemia from CTOs were treated. Occluded segments were crossed subintimally, and controlled re-entry was secured using the CrossPoint TransAccess catheter. This 6.2 F dual-lumen catheter contains an integrated 64-element phased array intravascular ultrasound scanner enabling targeting of structures. Intravascular ultrasound-guided luminal re-entry was achieved by advancing a 24-gauge needle to a desired length and delivering a 0.014" guide wire into the target lumen. The occluded segments were balloon dilated and stented using self-expanding nitinol stents. Effective luminal re-entry and re-establishment of antegrade flow occurred in all 6 patients. Time to recanalization ranged from 5 to 10 minutes. All patients were free of ischemic symptoms at 1 to 5 month follow-up. There were no procedure-related complications. Our preliminary results demonstrate the feasibility of using this catheter system for subintimal recanalization with controlled re-entry in CTOs. This approach can improve the technical success rate, reduce the time of the procedure, and minimize potential complications.

Aged↗

PubMed2004

Stent-graft treatment of extracranial carotid and vertebral arterial lesions.

Five patients with pseudoaneurysms of the carotid artery (n = 4) and an arteriovenous fistula of the vertebral artery (n = 1) were treated with stent-grafts. Commercially made devices were used in all but one of the patients. In four of the five patients, the pathology was successfully excluded. One patient had a small type-I endoleak. There were no immediate procedure-related complications or neurologic sequalae. All experienced immediate resolution of symptoms. One patient was lost to follow-up after discharge and another died 2 weeks after intervention. The remaining patients remained asymptomatic with patent stent-grafts after follow-up periods of 14, 16, and 46 months, respectively.

Adolescent↗

PubMed2004

Novel intravascular ultrasound-guided method to create transintimal arterial communications: initial experience in peripheral occlusive disease and aortic dissection.

PURPOSE: To report our experience using a commercially available catheter-based system equipped with an intravascular ultrasound (IVUS) transducer to achieve controlled true lumen re-entry in patients undergoing subintimal angioplasty for chronic total occlusions (CTO) or aortic dissections. METHODS: During an 8-month period, 10 patients (6 men; mean age 73.4 years) with lower extremity (LE) ischemia from CTOs (n=7) or true lumen collapse from aortic dissections (n=3) were treated. Subintimal access and controlled re-entry of the CTOs were performed with a commercially available 6.2-F dual-lumen catheter, which contained an integrated 64-element phased-array IVUS transducer and a deployable 24-G needle through which a guidewire was passed once the target lumen was reached. The occluded segments were balloon dilated; self-expanding nitinol stents were deployed. In the aortic dissections, fenestrations were performed using the same device, with the IVUS unit acting as the guide. The fenestrations were balloon dilated and stented to support the true lumen. RESULTS: Time to effective re-entry ranged from 6 to 10 minutes (mean 7) in the CTOs; antegrade flow was restored in all 7 CTOs, and the patients were free of ischemic symptoms at up to 8-month follow-up. In the aortic dissection cases, the fenestrations equalized pressures between the lumens and restored flow into the compromised vessels. There were no complications related to the use of this device in any of the 10 patients. CONCLUSIONS: Our preliminary results demonstrate the feasibility of using this catheter-based system for subintimal recanalization with controlled re-entry in CTOs and for aortic flap fenestrations in aortic dissections. This approach can improve the technical success rate, reduce the time of the procedure, and minimize potential complications.

Aged↗

PubMed2003

Complications of arterial closure devices.

As of July 2000, there were 4 closure devices with Food and Drug Administration (FDA) approval. The devices are successfully deployed in 89% to 98% of cases, and the complication rates are comparable to those seen with manual compression. Minor access site complications are defined as bleeding not requiring transfusion or surgical repair, hematoma (<5 cm), and pain at the puncture site. Major complications include hematoma (>5 cm), bleeding at the site requiring transfusion, pseudoaneurysm, arteriovenous fistula, retroperitoneal hemorrhage, plug embolization, groin infection, and death.

Anticoagulants↗

PubMed2003

Treatment of femoral artery pseudoaneurysms using ultrasound-guided thrombin injection.

Femoral artery pseudoaneurysms, a complication of femoral arterial puncture, is increasing in frequency with the proliferation of endovacular interventions. Pseudoaneurysms have historically been treated by open surgical repair, and more recently by ultrasound-guided compression. Ultrasound-guided compression is painful, and has a relatively low success rate of 51% to 73%. Since 1991, ultrasound-guided thrombin injection has become a treatment option. During injection of thrombin into a pseudoaneurysm, immediate thrombosis can be demonstrated within seconds. The entire procedure can be accomplished within 5 minutes, is simple to learn, and can be performed safely on an outpatient basis.

Aneurysm, False↗

PubMed2003

The safety, efficacy, and pharmacoeconomics of low-dose alteplase compared with urokinase for catheter-directed thrombolysis of arterial and venous occlusions.

PURPOSE: The purpose of this study was to compare the efficacy, complications, and costs associated with low-dose (<2 mg/h) alteplase (tissue plasminogen activator [t-PA]) versus urokinase for the catheter-directed treatment of acute peripheral arterial occlusive disease (PAO) and deep vein thrombosis (DVT). MATERIALS AND METHODS: A retrospective review was performed during sequential time periods on two groups with involved extremities treated with either t-PA with subtherapeutic heparin (TPA group) or urokinase with full heparin (UK group) at a single center. Treatment group characteristics, success rates, complications, dosages, infusion time, and costs were compared. RESULTS: Eighty-nine patients with 93 involved limbs underwent treatment (54 with DVT, 39 with PAO). The treatment groups were statistically identical (TPA: 45 limbs; 24 with DVT, 53.3%; 21 with PAO, 46.7%; UK: 48 limbs; 30 with DVT, 62.5%; 18 with PAO, 37.5%). The overall average hourly infused dose, total dose, infusion time, success rates, and cost of thrombolytic agent were as follows (+/- standard deviation): TPA, 0.86 +/- 0.50 mg/h, 21.2 +/- 15.1 mg, 24.6 +/- 11.2 hours, 89.4%, $466 +/- $331; and UK, 13.5 +/- 5.6 (10(4)) U/h, 4.485 +/- 2.394 million U, 33.3 +/- 13.3 hours, 85.7%, $6871 +/- $3667, respectively. Major and minor complication rates were: TPA, 2.2% and 8.9%; and UK, 2.1% and 10.4%, respectively. No statistical differences in success rates or complications were observed; however, t-PA was significantly (P <.05) less expensive and faster than urokinase. CONCLUSION: Low-dose t-PA combined with subtherapeutic heparin is equally efficacious and safe compared with urokinase. Infusions with t-PA were significantly shorter and less expensive than those with urokinase.

Adult↗

PubMed2003

CT-guided transthoracic needle aspiration biopsy of pulmonary nodules: needle size and pneumothorax rate.

PURPOSE: To evaluate the effect of coaxial needle size on pneumothorax rate and the diagnostic accuracy of computed tomography (CT)-guided transthoracic needle aspiration biopsy (TNAB) of pulmonary nodules. MATERIALS AND METHODS: Retrospective review of 846 consecutive CT-guided TNAB procedures was performed. A coaxial approach was implemented in all patients by using an 18- or 19-gauge outer stabilizing needle through which a smaller aspiration needle or automated biopsy gun was inserted for tissue sampling. Univariate and multivariate regression analyses were used to analyze coaxial needle size, age, sex, smoking history, lesion size, use of an automated core biopsy gun, number of needle passes, and frequency of chest tube placement. Sensitivity, specificity, and diagnostic accuracy were calculated for 676 patients with at least 18 months of clinical follow-up. RESULTS: Pneumothorax occurred in 226 of 846 patients. Coaxial needle size and patient age had a significant effect on pneumothorax rate. Pneumothorax occurred in 124 (38%) of 324 patients who underwent procedures with 18-gauge needles and in 121 (23%) of 522 patients who underwent procedures with 19-gauge needles (P <.001). The overall diagnostic accuracy was 96% for procedures performed with 18-gauge needles and 92% for procedures performed with 19-gauge needles, with a sensitivity of 95% and 89% and a specificity of 100% and 99%, respectively. Pneumothorax occurred in 153 patients older than 60 years, in 99 patients 60 years and younger (P <.02), in 90 patients older than 70 years, and in 162 patients younger than 70 years (P <.01). The relationship between pneumothorax rate and age as a continuous distribution was not significant (P <.07), nor were the 50- or 75-year age cutoffs (P <.06 and P <.9, respectively). CONCLUSION: Use of a smaller coaxial stabilizing needle produces a substantially decreased risk of pneumothorax with comparable diagnostic accuracy, sensitivity, and specificity for histopathologic diagnosis of pulmonary nodules.

Adolescent↗