TASK DEFINITION: Given an abstract, indicate which of the provided candidate titles (Option1 and Option2) best describes it (respond with the text of the title, not option1/2).
PROBLEM: Abstract: This study demonstrates that 20 to 30 microns porous, Replamineform silicone rubber prostheses remain isocompliant with adjacent arterial segments up to 8 months following implantation. This finding contrasts with the results of currently available prostheses, including autologous vein, which rapidly become minimally compliant. We conclude that this vascular construction is stable over the long-term following implantation and may improve the success of small internal diameter arterial reconstruction by eliminating failures caused by intimal hyperplasia.
Which is the apt title for the abstract? option1: Maintenance of compliance in a small diameter arterial prosthesis. option2: Severe chronic photosensitivity in association with acquired immunodeficiency syndrome [letter]

SOLUTION: Maintenance of compliance in a small diameter arterial prosthesis.

PROBLEM: Abstract: Rupture of an abdominal aortic aneurysm is readily diagnosed when the triad of abdominal or back pain, shock and a pulsatile abdominal mass are present. Clinical diagnosis can be difficult, however, when patients present with chronic pain and an aneurysm which is not readily palpable. In these patients with confusing abdominal symptoms, CT scan provides a rapid, noninvasive diagnosis. The acute leaking AAA has been documented, but only rarely. This report identifies two patients who ruptured an aortic aneurysm several "months" prior to operation--a "contained chronic" rupture.
Which is the apt title for the abstract? option1: "Chronic-contained" ruptured abdominal aortic aneurysm: is it real? option2: Systematic ankle stabilization and the effect on performance.

SOLUTION: "Chronic-contained" ruptured abdominal aortic aneurysm: is it real?

PROBLEM: Abstract: Ethane washout during low tidal volume (25-100 ml) high-frequency (3-40 Hz) ventilation (HFV) was studied in seven excised dog lungs. The lungs were initially equilibrated with 1% ethane, and then the concentration of ethane was monitored by mass spectrometry from multiple anatomic sites along the tracheobronchial tree during washout. We observed that the lung changed from a uniform distribution of ethane concentrations to a nonuniform distribution by a three-phase process. The first phase was nearly complete within the first 15 s and probably corresponds to concentration gradients being established in the central airways. During the second phase of washout, which lasted for several minutes, the concentrations in the various alveolar regions diverged. In the final phase, the regional concentrations remained at fixed ratios, and washout from all sites in the lung was at a constant fractional rate. These data are consistent with a model in which the duration of the second phase and the magnitude of the regional concentration differences established in this phase are dependent on both the magnitude of differences between regional transport paths and the nature of regional coupling by a common transport path to the airway opening.
Which is the apt title for the abstract? option1: Nonuniformity of canine lung washout by high-frequency ventilation. option2: Migraine: many things to many patients [news]

SOLUTION:
Nonuniformity of canine lung washout by high-frequency ventilation.