Intraluminal micromanometry: An evaluation of the dynamic performance of micro-extrusions and sleeve sensors

Conventional manometric techniques are unsuitable for studies in premature infants and small laboratory animals. We have therefore developed silicone rubber 5-lumen and 10-lumen micromanometric extrusions with an o.d. 2.0 mm and lumina of 0.35 mm i.d. This study evaluates the suitability of micro-extrusions for intraluminal perfusion manometry. Pressure offset, post-occlusion pressure rise rare and sphincter model studies were used to assess the manometric performance of the extrusions and a miniature sleeve sensor (25 mm long) at infusion rates of 0.01-0.1 mi min(-1). Micro-extrusions (5-lumen/10-lumen, respectively) had offsets (per 100 cm of length) of 3.8/5.0 mmHg at 0.01 mi min(-1) and 25.6/26.2 mmHg at 0.1 mt min(-1) and rise rates (in 160 cm lengths) of 64/43 mmHg sec(-1) at 0.01 mt min(-1) and 330/224 mmHg sec(-1) at 0.1 mt min(-1). Infusion rates 0.025 mt min(-1) produced rise rates 100 mmHg sec(-1). The miniature sleeve sensor had minimal resistance ro perfusion, rise rates of 3 mmHg sec(-1) at 0.01 mt min(-1) and 23 mmHg sec(-1) at 0.1 mt min(-1) and recorded pressure as accurately as a side hole. We conclude that the performance of micromanometric extrusions and sleeves is sufficient for intraluminal perfusion manometry.