Development of all-silicone detachable balloons

Treatment of cerebral vascular lesions such as carotid cavernous sinus fistulas and giant aneurysms is now being performed with intravascular detachable balloon embolization techniques. We have developed several types of all-silicone detachable balloons. Our balloons have self-sealing valves (with or without collars) and detach with simple traction. The self-sealing valve is smaller than 0.6 mm and the balloon can easily be placed through a 7-F catheter. We started clinical trials and a representative case was reported.     

Therapeutic embolization with detachable balloons

In our first 18 months' clinical experience with embolization in the chest and abdomen using detachable ballons, successful results were obtained in 34 of 38 patients. One and 2-mm detachable silicone balloons, which can occlude vessels 4–8 mm in diameter, were employed. Prolonged balloon inflation was routinely achieved using iso-osmotic iodipamide meglumine as the filler and limiting inflation volumes to experimentally determined maximums. Improvements in introducer catheter design simplified delivery of the balloon into a variety of circulations. Detachable balloons are not suitable for all embolization purposes, and they are frequently used in conjunction with other agents. When used properly, balloons produce a permanent occlusion that is extremely selective and potentially reversible up to a certain point in the procedure. The balloon technique enables the angiographer to occlude vessels at distances of 2–10 mm beyond the introducer catheter, thus avoiding the need for subselective catheterization and minimizing the dangers of inadvertent embolization. Biomedical Engineer, Becton-Dickinson Corporation, Rutherford, New Jersey 07070, USA Supported in part by a grant from Becton-Dickinson Corporation, Rutherford, New Jersey 07070, USA     

Treatment of varicoceles with detachable balloon embolization

Testicular varicocele is the single most common cause of male infertility. Varicoceles are due to either absent or nonfunctioning valves that permit retrograde flow in the internal spermatic vein resulting in increased temperature within the scrotum and interfering with spermatogenesis. Our method to treat varicoceles is occlusion of the spermatic vein with detachable silicone balloons. In our first 70 patients, this has proven to be a safe and effective nonsurgical method of occluding varicoceles in outpatients with results similar to those of surgery.     

The use of detachable balloons in neuroradiology

The development of the detachable balloon allows treatment of many neurological lesions, both congenital and acquired. We describe here a device that may be used easily. Complications and main indications are discussed on the basis of our experience with 114 cases.     

Carotid-cavernous fistula: closure with detachable silicone balloons

Detachable silicone rubber balloons, which do not require an outer catheter to effect detachment, were used to close carotid-cavernous fistulas in 10 patients. Closure was effective in nine of 10 patients. The internal carotid artery was intentionally occluded in two patients. The procedure resulted in inadvertent occlusion of the internal carotid artery in three patients. Follow-up studies showed no recurrence of the fistula; nor did any permanent neurologic deficits develop as a result of the procedure. The balloon catheter system and techniques of introduction are discussed in detail. The system is compared with other silicone and latex balloon systems that require a coaxial catheter for detachment. Technical and clinical problems are illustrated.     

Treatment of direct carotid-cavernous fistulas with detachable balloons

Experience with transarterial treatment of 14 direct carotid-cavernous fistulas using the Debrun technique with detachable balloons manually tied to the catheter is reported. Ten of the fistulas were occluded by balloons with concomitant occlusion of the internal carotid in one case. Another fistula closed spontaneously in connection with the embolization procedure. Three fistulas were treated with surgical trapping after recurrence. The transvenous approach was attempted in three cases but failed. Four complications occurred, two with clinical consequences as the patients developed neurologic deficits. Except in four cases with persistent or slowly regressing orbital palsies all signs and symptoms of the fistula disappeared after successful occlusion. The use of detachable balloons for selective occlusion is in experienced hands a rather safe and simple method with good results. Large fistulas offer most problems, and to avoid progression in fistula size the treatment should be undertaken as soon as possible after diagnosis.     

Guide-wire-directed detachable balloon: clinical application in treatment of varicoceles.

Wire-directed detachable balloons were used in embolization treatment of varicoceles in six patients. Advancement of the balloon over a guide wire allowed easy embolization of the internal spermatic vein at the level of the inguinal ring. Additional detachable balloons were used to occlude the collateral vessels to the varicocele. This method proved highly effective in embolization of tortuous veins and in placement of multiple balloons.     

Double traumatic caroticocavernous fistula and its treatment by detachable balloons

Summary A case with two separate fistulous caroticocavernous communications on the same side and their successful endovascular management with preservation of the carotid artery are reported.     

MR evaluation of neurovascular lesions after endovascular occlusion with detachable balloons

Three patients with surgically inaccessible giant carotid aneurysms/pseudoaneurysms and one patient with carotid cavernous fistula had endovascular occlusion with detachable silicone balloons filled with Cholografin. MR was performed before the procedures in three cases and again 18 hr to 44 days after embolization in all four cases. The age-related changes of arterial thrombi, as well as the optimal timing and value of different pulse sequences in the noninvasive follow-up, were evaluated. Arterial thrombi have some characteristics in common with intracerebral hematomas, being isointense on T1-weighted spin-echo images during acute phase and subsequently acquiring hyperintense signals on both T1- and T2-weighted spin-echo images during the subacute and chronic phases. Additional observations are that (1) hyperacute (less than 24 hr old) thrombus is hyperintense on T2-weighted spin-echo sequences; (2) hemosiderin is less conspicuous in chronic intraluminal thrombi than in intracerebral hematomas of comparable size; and (3) thrombosis is initiated at a site remote from the apex of the aneurysm and then progresses centripetally. The Cholografin-filled balloon is hypointense to gray matter on T1-weighted spin-echo images and isointense to both hyperacute and chronic thrombus on T2-weighted spin-echo images. The optimal timing and sequence for MR follow-up of a thrombosed aneurysm with conventional spin-echo technique is beyond 7 days on T1-weighted spin-echo images. The in vivo appearance of Cholografin-filled silicone balloons does not change appreciably on T1- and T2-weighted spin-echo sequences up to 6 weeks if filled according to the manufacturer's specification.     

Diffuse hepatic hemangiomas: percutaneous transcatheter embolization with detachable silicone balloons

Two infants with severe congestive cardiac failure secondary to diffuse hepatic hemangiomas were treated by percutaneous transcatheter embolization of the hepatic arteries using detachable silicone balloons. One infant experienced dramatic improvement of the cardiac failure and showed no impairment of hepatic function. The other infant remained in a low cardiac output state following the procedure and developed acute hepatic and renal failure followed by generalized sepsis and death. Autopsy examination revealed massive hepatic hemangioendothelioma as well as areas of necrotic and viable liver parenchyma. A review of reported patients with hepatic hemangiomas treated by hepatic artery ligation or embolization showed no others who had hepatic failure. These techniques were curative in 14 of 18 patients (78%), an improvement compared with the results of other available methods of therapy.     

Embolotherapy with detachable silicone balloons: technique and clinical results.

Catheter techniques and early clinical results of therapeutic embolization with detachable silicone rubber balloons are described in 13 patients. Effective control of post-traumatic or spontaneously occurring hemorrhage or preoperative devascularization of neoplasms was achieved in 10 patients. Three additional patients, one each with pelvic arteriovenous malformation. pulmonary arteriovenous malformation, and hemangioendothelioma of the liver, were partially treated by balloon occulsion. Therapeutic embolization with detachable silicone balloons provides a method of long-term, extremely selective arterial occlusion with reduced risks from inadvertent embolization of neighboring circulations.     

Correction of erectile impotence of venous origin using detachable balloons and coils

The authors review a radiological classification of venous impotence and report their therapeutic approach. 13 patients with a venous insufficiency of Santorini's plexus were treated by detachable balloons and coils. This technic was convenient in 11 of the 13 cases. 5 patients with a superficial venous insufficiency were treated by embolization by coils. The results in this group appear to be good in 4 cases.     

Permanent inflation of detachable balloons with a low-viscosity, hydrophilic polymerizing system

A polymer system was developed for use in permanent inflation of detachable balloons, to avoid long-term reliance on the integrity of balloon shells or valve mechanisms. This system is based on 2-hydroxy-ethyl methacrylate (HEMA) as the monomer, in combination with a cross-linking agent and a water-soluble curing system. The low-viscosity, hydrophilic mixture can be exchanged through a small-bore catheter into a detachable balloon and polymerizes in 40-60 minutes at body temperature. Partially polymerized HEMA can cause vascular occlusion; hence, careful timing of balloon detachment is required. The evolution of the radiographic appearance of HEMA-filled balloons is predictable. The balloons remain radiopaque on plain radiographs as long as the balloon shell and valve mechanisms are competent. After rupture of the shell or failure of the valve mechanism, the balloons become invisible on plain radiographs but remain hyperattenuating on computed tomography scans.     

The permeability of detachable latex rubber balloons. An in vitro study

Previous studies have shown that a silicone rubber balloon filled with a hyperosmolar solution of contrast medium expands and may rupture because the wall acts as a semipermeable membrane. The deflation of latex rubber balloons in vivo has been attributed to the same cause. The authors investigated the behavior of latex rubber balloons filled with metrizamide solutions ranging from hyperosmolar to hypo-osmolar relative to plasma. When balloons were immersed in plasma, tritiated water passed bidirectionally through the wall at a rate unrelated to the concentration or volume of the contrast medium in the balloon. There was no exchange of sodium ions across the wall, and the osmolality of the metrizamide did not change over a period of up to six weeks. The authors conclude that deflation of a latex rubber balloon during the first few hours or days is not due to osmosis.