Given an abstract of a paper, generate a title for this paper such that conveys the key focus of the paper.

[EX Q]: Abstract: Four patients with recurrent severe angina and evidence of myocardial ischemia two to six months after surgical coronary revascularization have been submitted to percutaneous transluminal angioplasty of the distal insertion of internal mammary artery grafts or of the recipient vessel distal to it. These cases illustrate the feasibility and safety of transluminal angioplasty of right and left internal mammary artery grafts, using the mammary artery as a way of access.
[EX A]: Percutaneous transluminal angioplasty of right and left internal mammary artery grafts.

[EX Q]: Abstract: Cervical traction and lumbopelvic traction are commonly prescribed for relief of neck pain and low back pain, respectively. Scientific validation of efficacy is scant, but considerable empirical benefit has been observed. In the absence of contraindications and with appropriate application, cervical and lumbopelvic traction may be used to provide symptomatic relief of neck and low back pain.
[EX A]: Cervical and lumbopelvic traction. To stretch or not to stretch.

[EX Q]: Abstract: The prognostic value of marrow chromosome findings was examined in 242 patients with preleukemic myelodysplastic syndromes (MDS) or myeloproliferative disorders (MPD), with emphasis on the significance of single versus multiple karyotypic changes. In both groups, the results showed that patients with multiple chromosome abnormalities in a marrow clone had a very high probability of early death, from progression to leukemia or from other complications of hematopoietic dysfunction. Conversely, in patients with a hemic clone having only one karyotypic alteration (involving a single chromosome or single translocation), survival over 2 years was only slightly reduced as compared to those without chromosome abnormality. The only single karyotypic alteration perhaps associated with a markedly shortened survival was monosomy 7. These findings suggest that the conclusions of previous studies concerning the grave consequences of chromosome alterations in preleukemia largely reflect the clinical significance of clones with multiple cytogenetic changes. Prior knowledge of the karyotypic status of preleukemic patients should be helpful in evaluating current attempts to find effective treatment for these difficult disorders.
[EX A]:
Chromosome studies in preleukemic states. V. Prognostic significance of single versus multiple abnormalities.