The natural history of epistaxis in hereditary hemorrhagic telangiectasia

The purpose of this retrospective study is to document the natural history of epistaxis in patients with hereditary hemorrhagic telangiectasia. A telephone questionnaire was administered to 73 patients who had been previously screened for pulmonary arteriovenous malformations (PAVMs). The incidence of epistaxis in this population was 93%, with a mean onset age of epistaxis of 12 years, a mean frequency of bleeding of 18 episodes per month, and a mean duration of bleeding of 7.5 minutes. More than 90% of patients experienced the onset of epistaxis before the age of 21 and symptoms were progressive with age. There were no differences in the age of onset, frequency of epistaxis, or duration of epistaxis between patients with PAVMs versus those without PAVMs. Although the natural history of epistaxis does not predict the presence or absence of pulmonary arteriovenous malformations, epistaxis is an early marker of the disease, hereditary hemorrhagic telangiectasia, and might guide screening for pulmonary and cerebral arteriovenous malformations in children of affected parents.

Transcatheter detachable balloon embolotherapy for catheter-induced pulmonary artery pseudoaneurysm

Pulmonary artery pseudoaneurysm formation may be due to various etiologies, including trauma, pulmonary artery catheterization, infection, and tumor. Transcatheter embolization is a nonsurgical management technique that may be utilized in many of these patients to occlude the affected artery and to prevent further extravasation. Recently, two patients with pulmonary artery pseudoaneurysm formation after balloon-tipped catheter placement were successfully managed with transcatheter embolotherapy with detachable silicone balloons. The article describes their diagnosis and management.

Experimental treatment of thrombotic vascular occlusion

The role of laser energy in the treatment of thrombotic vascular occlusion was evaluated in two sets of experiments. First, 10 polytetrafluoroethylene grafts were used to replace segments of the superficial femoral arteries in dogs and were thrombosed by distal ligation. Occlusion was maintained for one hour, or for 7, 14, 21, and 28 days in each of two grafts. Patency was restored in all 10 grafts without perforation or anastomotic disruption using a 2 mm hot tip probe powered by an Argon laser. However, increased organization of thrombus related to the duration of occlusion lead to decreased laser channel diameters, and 75% of the 28 day thrombus remained in the graft after recanalization. The second experiments tested the added benefit of thrombolytic infusion following laser recanalization. Bilateral external iliac artery thrombosis was induced in dogs by operative vessel isolation, de-endothelialization, and thrombin injection. At 7 days the efficacy of laser-assisted thrombolysis (LAT) versus enzymatic thrombolysis (ET) alone was compared. Eight vessels underwent ET by urokinase (4000 I.U./min.); 14 vessels were laser recanalized prior to thrombolytic infusion. LAT was performed from a carotid artery approach in 8 vessels (antegrade) and from a femoral artery in 6 vessels (retrograde). In contrast to studies using the hot tip alone, both ET and LAT accomplished complete thrombus removal. However, LAT lead to significant iliac arterial flow in 9 +/- 8 min. (antegrade) and 25 +/- 8 min. (retrograde) while ET required 109 +/- 47 min (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Ex-vivo results using a new pullback atherectomy catheter (PAC)

In order to evaluate the feasibility of performing definitive atheromatous plaque removal using a novel retrograde cutting (Pullback) atherectomy catheter, pullback atherectomy was performed in 13 severely diseased cadaveric superficial femoral arteries. All experiments were performed using cadaver tissue either mounted in a perfusion/mounting chamber (n = 10) or left in situ (n = 3). In general, a single cut was made with each of three sequentially larger atherectomy catheters (2.5 mm, 3.0 mm, and then 3.5 mm devices). The results were evaluated by angiography and by light microscopy. Nine of the 13 experiments were performed in totally occluded vessels. The mean pre-atherectomy stenosis (all specimens) was 95 +/- 3%, with a final mean postatherectomy stenosis of 21 +/- 5%. There was one vessel performation. We conclude from these preclinical studies that retrograde atherectomy with the Pullback Atherectomy Catheter is a feasible means of performing definitive atherectomy. Despite the promising potential of retrograde atherectomy, little can be said with certainty about the clinical utility of such a device at this early stage.

Status of admitting privileges for university-affiliated diagnostic radiology departments

Members of the Society of Chairmen of Academic Radiology Departments (SCARD) from 135 university hospitals in Canada and the United States were surveyed regarding their experience in admitting patients to diagnostic radiology departments between 1986 and 1989. One hundred departments (74%) replied; of these, 33 departments (33%) admitted patients during 1989. From 1986 to 1989 the percentage of diagnostic radiology departments admitting patients rose from 20% to 33%. Forty-one departments had admitting privileges, and nine departments had applied for admitting privileges. The remaining 50 departments were content to admit patients to medical and/or surgical services or had no interest in obtaining admitting privileges. The rapid growth of noncardiac interventional procedures, the obvious benefit to patients whose disease is manageable with imaging-guided therapy, the increasing interest of nonradiologists in performing interventional radiologic procedures, and the potential financial benefits to the hospital that are associated with short patient stays provide incentive for diagnostic radiologists to admit patients for cardiovascular and interventional procedures.

Etiologic factors in renovascular fibromuscular dysplasia. A case-control study

The role of several factors that have been suggested as being of etiologic importance in renovascular fibromuscular dysplasia was examined in a case-control study of 33 patients with angiographically demonstrated fibromuscular dysplasia and 61 renal transplant donor control subjects with normal renal arteries. The factors studied included use of oral contraceptive agents or markers of sex hormone dysfunction, mechanical stress to the renal artery wall, human lymphocytic antigen (HLA) type, cigarette smoking, history of hypertension for more than 5 years, and family history of cardiovascular disease. The risk of fibromuscular dysplasia was significantly (p = 0.003) increased (odds ratio = 4.1, 95% confidence interval = 1.5-10.9) among cigarette smokers. A significant (p less than 0.001) dose-response relation was noted between cigarette use and the risk of fibromuscular dysplasia developing (odds ratio = 8.6 for those who had smoked more than 10 pack-years). Personal history of hypertension more than 5 years was also associated (odds ratio = 5.0, 95% confidence interval = 1.1-22.8) with a significantly (p = 0.036) increased risk for the development of fibromuscular dysplasia. HLA-DRw6 antigen was more common in the 33 fibromuscular dysplasia patients than in the 61 renal transplant donor control subjects (odds ratio = 3.00, p = 0.067) or a second group of 934 ambulatory control subjects (odds ratio = 2.51, p = 0.031). Adjustment for cigarette smoking increased the odds ratio to 5.0 (95% confidence interval = 1.3-19.6). There was a positive though not statistically significant (odds ratio = 1.7, p = 0.175) association noted between family history of cardiovascular disease and fibromuscular dysplasia.(ABSTRACT TRUNCATED AT 250 WORDS)

Benign postoperative biliary strictures. Operate or dilate?

At The Johns Hopkins Hospital from 1979 through 1987, 42 patients had 45 procedures for benign postoperative biliary strictures. Three patients were managed with both surgery and balloon dilatation. Twenty-five patients underwent surgical repair with Roux-Y choledocho- or hepaticojejunostomy with postoperative transhepatic stenting for a mean of 13.8 +/- 1.3 months. Twenty patients had balloon dilatation a mean of 3.9 times and were stented transhepatically for a mean of 13.3 +/- 2.0 months. The two groups were similar with respect to multiple parameters that might have influenced outcome. Mean length of follow-up was 57 +/- 7 and 59 +/- 6 months for surgery and balloon dilatation, respectively. No patients died after any of the procedures. The same definition of a successful outcome was applied to both groups and was achieved in 88% of the surgical and in only 55% of the balloon dilatation patients (p less than 0.02). Significant hemobilia occurred more often with balloon dilatation (20% vs. 4%, p less than 0.02). The total hospital stay and cost of balloon dilatation was not significantly different from surgery. We conclude that surgical repair of benign postoperative strictures results in fewer problems that require further therapy. Nevertheless balloon dilatation is an alternative for patients who are at high risk or who are unwilling to undergo another operation.

Porcine model for the development of interventional techniques in the gallbladder

A technique that permits repeated access to the porcine gallbladder through a surgically placed 18 French latex catheter is described and experience with this system in 22 swine is discussed. This porcine gallbladder model produces a reliable and reproducible means for studying clinically applicable interventional procedures.

Percutaneous laser probe femoropopliteal angioplasty: a preliminary experience

Percutaneous laser probe "hot tip" angioplasty procedures were performed on 47 occluded femoropopliteal artery segments in 27 men and 10 women ranging in age from 31 to 92 (mean, 64.7) years. Indications for the procedure included claudication in 29 (78%) segments, and the occlusion lased was greater than 7 cm in length in 51% of the procedures. Failure to recanalize the occlusion occurred in 14 (30%) segments, and recanalization followed by in-hospital reocclusion occurred in seven (15%) segments, yielding an initial failure rate of 45%. Initial failures were noted in 40% of the less than 3 cm occlusions, 33% of the 4 to 7 cm occlusions, and 54% of the greater than 7 cm occlusions. In nine (43%) instances in these 21 failures there was extension of the occluded segment or decline of the ankle/brachial index or both, precipitating the need for surgery in three (18%) of these 17 patients. Among the successfully treated group, 17 (65%) of these vessels in 15 patients reoccluded from 1 to 14 (mean, 3 1/2) months after the procedure. Cumulative patency among the successfully lased vessels was 69% at 1-month, 38% at 6 months', 29% at 12 months', and 14% at 15 months' follow-up. Fifteen-month patency was 7% of the entire series of 47 vessels treated. Eighteen complications occurred after 15 (32%) of these 47 procedures. Based on these results, the widespread application of laser probe angioplasty cannot be justified without further clinical and laboratory investigation.

Ocular manifestations in hereditary hemorrhagic telangiectasia (Rendu-Osler-Weber disease)

Although hereditary hemorrhagic telangiectasia is a cause of blood tears from the conjunctival telangiectasias, visual loss from intraocular vascular malformations is a rare complication. We examined 20 patients with hereditary hemorrhagic telangiectasia to determine the prevalence of ocular abnormalities in this disease. Seven patients (35%) had conjunctival telangiectasias and two (10%) had retinal vascular malformations.

Frequency and determinants of adverse reactions induced by high-osmolality contrast media

To determine the frequency of and risk factors for adverse reactions to high-osmolality contrast media, the authors prospectively studied hospitalized patients undergoing cardiac catheterization. The authors also studied patients undergoing peripheral angiography and contrast material-enhanced computed tomography (CT) of the head or body who met at least one of the following criteria thought to increase the risk of adverse reactions: age of more than 60 years, diabetes, renal or liver disease, concurrent nephrotoxic drug use, or a history of allergic reactions (n = 795). Criteria were defined and used to group adverse reactions into three classes of clinical severity. Overall, class I (mild), class II (moderate), and class III (severe) reactions occurred in 362 (45%), 44 (5.5%), and three (0.4%) patients, respectively. Class II reactions were relatively common (25%) in patients undergoing cardiac catheterization yet were uncommon (2%) in patients undergoing the other three procedures. Nephrotoxicity occurred in 18 of 651 patients who had follow-up creatinine levels obtained at 48-72 hours. With multivariate regression analysis, the only risk factor (P less than .05) for combined class II and III reactions was diabetes. Diabetes, furosemide use, and a history of atopy (odds ratio = 2.8) were associated with nephrotoxicity (P less than .05). Underlying renal insufficiency was not a risk factor for nephrotoxicity.

Pulmonary arteriovenous malformations: techniques and long-term outcome of embolotherapy

Over a 10-year period, 276 pulmonary arteriovenous malformations (PAVMs) were occluded with balloon embolotherapy in 76 patients, 67 (88%) of whom had hereditary hemorrhagic telangiectasia. Eleven patients (14%) were discovered by means of family screening with measurement of arterial blood gases and chest radiography. Epistaxis, dyspnea, hemoptysis, and hemothorax occurred in 79%, 71%, 13%, and 9% of patients, respectively. Clinical histories of strokes and transient ischemic attacks were present in 18% and 37% of patients, respectively. Computed tomographic scans of 59 patients showed stroke in 36%. Sixty-five percent of PAVMs were located in the lower lobes, which correlated with the finding of more pronounced hypoxemia in the upright position. After embolotherapy, symptomatic hypoxemia was corrected, and serial values have remained constant for 5 years. Complications were minimal, and no patient required surgery. Balloon embolotherapy is effective long-term therapy for PAVMs, and family screening should be pursued because of the possibility of a higher frequency of paradoxical embolization (stroke) than previously recognized.

Congenital arteriovenous malformations: tailored embolotherapy

Congenital arteriovenous malformations (AVMs) involving the pelvis or an extremity were occluded in 16 symptomatic patients, who subsequently underwent tailored embolotherapy. An additional 11 patients did not undergo embolization due to unfavorable vascular anatomy or lack of significant symptoms. Permanent occlusive agents including isobutyl cyanoacrylate, particles of polyvinyl alcohol foam, and coils were used to embolize the multiple feeding vessels and, when possible, the nidus of the AVM. All patients experienced dramatic reduction in pain and resolution of ulceration and bleeding, with a mean follow-up period of 41 months. Symptoms recurred in four patients but again resolved with repeat embolization. The authors conclude that selective and repetitive embolization is highly effective in palliation of symptomatic congenital AVMs.

Contrast medium-induced adverse reactions: economic outcome

Because the cost of managing an expected greater number of adverse reactions when high-osmolality contrast media (HOM) are used could offset the higher material cost of low-osmolality contrast media (LOM), a prospective study was done of 795 inpatients undergoing any of four procedures involving intravascular injection of HOM: cardiac catheterization, peripheral angiography, head computed tomography (CT), or body CT. The resources used in managing HOM-induced adverse reactions were measured, and the costs of these resources were estimated. Four hundred five patients (51%) had adverse reactions. Reactions were grouped into three classes according to their severity. Class 1 (mild) reactions occurred in 358 patients (45%), class 2 (moderate) reactions occurred in 44 patients (6%), and class 3 (severe) reactions occurred in three patients (0.4%). Ninety-nine patients (12%) consumed resources as a result of an adverse reaction. The average cost of these resources per patient undergoing examination was $1.07 to the radiology department, $5.83 to the hospital, and $12.93 to a charge-paying insurer. Mean (+/- standard deviation) cost to the hospital for managing class 1, class 2, and class 3 reactions were $2.52 +/- $5.33, $24 +/- $54, and $910 +/- $749, respectively. By comparison, the difference in material cost of HOM versus LOM ranged from $93 for body CT to $179 for cardiac catheterization. Even if LOM were to induce no adverse reactions, the increased material cost associated with universal substitution of LOM for HOM would be greater than the expected cost of managing adverse reactions when HOM are used.

Use of low-osmolality contrast media in a price-sensitive environment

Over the past 3 years, three radiographic contrast media that are lower in osmolality than traditional contrast media have become available in the United States. These lower osmolality media have been reported to produce fewer adverse reactions than the higher osmolality media, but they cost 10 to 20 times more than higher osmolality media. To explore hospital and physician decision-making regarding the use of lower osmolality media in the increasingly price-sensitive health-care environment, we surveyed the 40 hospitals in the United States that received the most funding from the National Institutes of Health in 1985. Radiologists in 27 (68%) of the hospitals responded. Of these, 93% believed lower osmolality media improve the quality of patient care. However, nearly half of responding institutions limited the use of lower osmolality media. On average, in 1986 lower osmolality media were used in 9% of procedures in which contrast media were injected intravascularly. The decision to limit use was made primarily by radiologists, rather than hospital administrators, and was based on concerns regarding the high price of lower osmolality media. Twelve respondents had developed guidelines for appropriate use of lower osmolality media, but only 25% of these had developed mechanisms to ensure or increase compliance with those guidelines. Only one respondent (4%) reported that he routinely informs patients of the issues and tradeoffs involved in deciding whether to use lower or higher osmolality media. We conclude that cost is an important factor in physicians' and hospitals' choices of contrast media and that increased attention should be given to defining appropriate procedures to follow when informed consent is obtained for the use of contrast material.

Streamlining operation of an admitting service for interventional radiology

The authors describe how operations of an inpatient admitting service for interventional radiology were improved by developing a clinic and hiring a physician's assistant. The service, begun in 1982, was managed by a senior radiologist and fellows. Because of increasing admissions (from a mean of 52 per year in 1982-1985 to 110 per year in 1985-1987), a 1/2-day, twice-weekly clinic was created in 1985 to evaluate new patients and perform follow-up examinations. In 1986 a physician's assistant was hired to assist in the clinic and during patient admissions. Use of the clinic and physician's assistant streamlined patient flow and management during hospitalization. This resulted in a decrease in mean length of stay for patients undergoing angioplasty (from 3.74 days in 1982-1983 to 2.41 days in 1986-1987). This decrease means cost savings for the hospital under the prospective payment system. Other benefits include improved physician-patient relationships and follow-up, new patients for colleagues (15% of patients had anatomy unsuitable for interventional procedures and were referred to staff surgeons), and increased professional fees.

Treatment of a case of thromboembolism resulting from thoracic outlet syndrome with intra-arterial urokinase infusion

A 36-year-old man with thoracic outlet syndrome, admitted to the hospital with digital ischemia from subclavian artery thrombosis and distal embolization, was given intra-arterial urokinase. Thrombus in the subclavian artery was lysed successfully and peripheral emboli were partially cleared, resulting in relief of digital symptoms. Although surgical decompression and vascular reconstruction at the thoracic outlet may be necessary, this technique provides a means of recanalizing small distal vessels.