External Radiation for Restenosis

Background: Restenosis after balloon angioplasty remains a substantial clinical problem. Endovascular radiation has been shown to reduce neointima formation in animal models of restenosis, and the results of early clinical trials are promising. However, this technique has several limitations, particularly, the inability to delay or fractionate therapy and inhomogeneous dose distribution. These shortcomings might be overcome by delivering radiation therapy from an external approach. This study investigated the effects of high dose external beam irradiation on balloon-injured pig coronary arteries. Methods and Results: Eight domestic juvenile pigs underwent balloon overstretch injury. External beam irradiation (21 Gy) of the heart was performed within 2 hours on four pigs and the remainder were not irradiated (controls). Sections of paraffin embedded injured arteries, perfusion fixed at 4 weeks, were measured by computer-assisted histomorphometry. Luminal area in the 21-Gy group was 3.84 ± 1.80 mm² compared to 2.0 4 ± 0.49 mm² in the controls (P < 0.01). Neointimal area and maximal intimal thickness were reduced in the 21-Gy group (0.23 ± 0.36 vs 1.36 ± 0.67mm², P < 0.0005; 0.25 ± 0.35 vs 0.64 ± 0.2, P < 0.01, respectively). Diffuse focal interstitial fibrosis was observed in the myocardium of the irradiated group. Conclusions: At 21 Gy, external beam irradiation significantly increased lumen size and reduced neointima formation in balloon-injured pig coronary arteries. However, myocardial damage was also induced by irradiation of the whole heart at this dose.     

Excimer Laser Angioplasty with Adjunctive Balloon Dilatation Versus Balloon Dilatation Alone for the Treatment of In-Stent Restenosis: Results of a Randomized Single-Center Study

Background: Laser ablation of neointimal tissue prior to balloon dilatation has been shown to be a potential treatment modality for restenosis within previously implanted stents. It remains controversial whether this treatment provides superior acute and long-term results compared to conventional balloon dilatation. Methods and Results: Between November 1995 and November 1996, 96 patients with significant (≥ 50%) in-stent restenosis were randomized to receive excimer laser angioplasty with adjunctive balloon dilatation (ELCA + PTC A, n = 47) or PTCA alone (n = 49). Both groups did not differ with regard to gender, clinical history, location of the lesion, reference diameter, or lesion length. Angiographic success was achieved in 46 patients with ELCA + PTCA (98%) and in 48 patients with PTCA alone (98%). In-hospital complications included acute closure in one patient of each group, one CABG, one repeat PTCA, and one non-Q wave MI with ELCA + PTCA, versus two bleeding and one death with PTCA. Clinical follow-up was obtained in all patients, while angiographic follow-up was available in 35 of 47 (ELCA+PTCA) versus 35 of 49 (PTCA) patients with a mean follow-up time of 163 ± 81 days. With ELCA+PTCA, MLD increased from 0.82 ± 0.38 to 1.99 ± 0.33 mm versus 0.81 ± 0.39 mm to 2.07 ± 0.60 mm with PTCA (P = NS). At follow-up, MLD was 1.32 ± 0.60 mm with ELCA + PTCA versus 1.45 ± 0.75 mm with PTCA (P = NS). Late adverse events included nine repeat PTCA with ELCA +PTCA (19%) versus 12 with PTCA (24%), three CABG with ELCA +PTCA (6%) versus two with PTCA (4%), and one death (2%) with PTCA (P = NS). Angiographic restenosis rate was 52% with ELCA + PTCA versus 47% with PTCA alone (P = NS). Conclusion: Our data suggest that excimer laser angioplasty with adjunctive balloon dilatation for the treatment of in-stent restenosis provides similar acute results as plain balloon dilatation and may offer no advantage over PTCA alone with regard to intermediate-term outcomes.     

Congenital Myofibroma Masquerading as an Ulcerated Infantile Hemangioma in a Neonate

Abstract: We report a case of a solitary infantile myofibroma masquerading as an ulcerated infantile hemangioma. Infantile myofibroma is a rare soft tissue tumor that has a good prognosis in the solitary form. It may be difficult to distinguish clinically from more common tumors of infancy such as an infantile hemangioma or from other rare entities and therefore requires a biopsy for definitive diagnosis.     

INTESTINAL PARASITE INFECTIONS OF MAN IN CHENGTU AND ITS VICINITY*

Information regarding incidence and intensity of parasites of the intestinal tract of man in West China is meaget and fragmentary. While undertaking a series of investigations to determine the sources and modes of transmission of human intestinal parasites in Chengtu (the results of these studies will be published soon) it was felt neces- sary to secure some more specific knowledge of the prevalence of the intestinal parasites of man in the district concernecl. For this reason the present investigation was carried out. .     

Sinus Node Recovery Time Assessment Revisited: Role of Pharmacologic Blockade of the Autonomic Nervous System

Sinus Node Recovery and Autonomic Blockade. Sinus node recovery time assessment is used to diagnose clinically significant sinus node dysfunction (SND) when Holter has failed to prove a relationship between sinus bradyarrhythmias and symptoms, but consensus has not been reached as to the value of including assessment after pharmacologic blockade of the autonomic nervous system. This issue was addressed in the present study performed on 52 patients with syncope or presyncope/dizziness (n = 48), sinus bradyarrhythmias (n = 45), or both (n = 41). Group 1 consisted of 13 patients with a proven relationship between symptoms and sinus bradyarrhythmias. Group 2 consisted of 39 patients with suspected SND. The protocol included three pacing periods at two pacing rates and was performed at baseline (n = 52), after single doses of atropine and propranolol (0.02 mg/kg and 0.1 mg/kg, respectively) (n = 41), and again after a second dose (n = 29). The sensitivity of prolonged recovery times was 77% in group 1. Among group 2 patients, 56% had prolonged recovery times at baseline (79% when including the results after the first dose of drugs). The second dose did not contribute diagnostic information, but it caused significant adverse reactions in 7 of 29 patients (P < 0.001). These 7 patients were all older than 60 years. Assessment of sinus node recovery time after pharmacologic blockade of the autonomic nervous system thus increases the sensitivity of the method in patients with suspected SND and normal baseline results. However, only 50% of the initially suggested doses of atropine and propranolol is sufficient and eliminates the risk for significant adverse reactions.