Measurement of vaginal and minor labial oxygen tension for the evaluation of female sexual function.

PURPOSE: Female sexual dysfunction is a new, rapidly expanding area of sexual medicine. Female sexual arousal disorder may, in part, be due to decreased pelvic blood flow. Therefore, we developed a simple noninvasive reproducible technique to measure vaginal and minor labial blood flow. MATERIALS AND METHODS: The study included 12 healthy young women able to have orgasm through self-stimulation. Observations at orgasm were recorded in the 12 subjects after self-stimulation. Measurements were obtained intravaginally and on the minor labia using a modified Clark oxygen electrode to obtain partial oxygen pressure (pO(2)). RESULTS: Mean basal vaginal value was 3.8 +/- 0.9 mm Hg and mean basal pO(2) on the minor labia was 18.3 +/- 3.7 mm. Hg. As soon as self-stimulation was initiated an increase in oxygen tension occurred and continued during sexual stimulation. Just before orgasm a further increase was noted with peak values measured immediately after the orgasm began (pO(2) 28.6 +/- 3.1 mm Hg intravaginally and 47.3 +/- 4.1 labial). Labial pO(2) measurement decreased relatively rapidly soon after orgasm. The time to return to basal vaginal values after orgasm varied from 20 to 30 minutes. CONCLUSIONS: Previously, changes in female sexual arousal responses have been difficult to evaluate and quantify clinically. We developed a simple noninvasive reproducible technique to measure vaginal and minor labial blood flow. Age based and cycle dependent normograms now can be produced for vaginal and labial blood flow using this method.

Hydrodynamics of aortic arch vessels during perfusion through the right subclavian artery.

BACKGROUND: Performing subclavian artery cannulation in patients with an atherosclerotic ascending aorta or acute aortic dissection is of growing interest. To increase knowledge about pressure and flow distribution in the arch vessels, we investigated the in vitro perfusion characteristics in right subclavian artery cannulation. METHODS: Pressures and flow rates in the arch vessels of an aortic arch model were measured during perfusion through the right subclavian artery with different geometries and varying flow rates. Flow visualization was performed by laser light. RESULTS: In normal subclavian artery geometries, pressure and flow showed a significant increase in only the right common carotid artery (8 mm Hg and 25.5 mL/min, respectively, at 5.5 L/min pump flow). In cases of 50% stenosis at the right subclavian artery origin, a reduction of pressure and flow (6 mm Hg and 22.5 mL/min, respectively, at 5.5 L/min pump flow) in the right carotid artery caused by a suction effect was observed. CONCLUSIONS: Right subclavian artery cannulation provides a valuable alternative for ascending aortic cannulation, enabling nearly balanced arch vessel perfusion. Stenosis at the right subclavian artery origin carries the potential risk of slightly reduced perfusion of the right common carotid artery with questionable clinical relevance.

An in-vitro evaluation of aortic arch vessel perfusion characteristics comparing single versus multiple stream aortic cannulae.

OBJECTIVE: During extracorporeal circulation design and orientation of aortic cannulae tips mainly determine flow pattern in the aortic arch and arch vessels which is the objective of this in vitro study, comparing single versus multiple stream cannulae. METHODS: In an aortic arch glass model, jet streams of 21-24 French aortic cannulae which were inserted in the ascending aorta were directed alternatively at the different arch vessels. Flows and pressures in the arch vessels were measured at pump flows of 3-6 l/min. RESULTS: With optimal orientation of the jet stream in the aortic arch, no preferential flow in the arch vessels was seen. In the single jet stream aortic cannulae group a significant parallel increase in flow and pressure in the jet streamed arch vessels compared to the non-jet streamed arch vessels occurred (P < 0.05). With the jet stream directed on vessel 2 (left carotid vessel) there was a significant pressure and flow difference comparing the two non-jet streamed vessels with each other (P < 0.03). In the single stream 24 French cannulae the highest vessel pressure of 168 mmHg and an increase in flow of 186 ml/min was measured in the jet streamed left carotid artery at 6 l/min pump flow. The multiple stream cannulae provoked the highest vessel pressure of 106 mmHg in the corresponding jet streamed vessel and an increase in flow of 20 ml/min. CONCLUSION: Tip design of aortic cannulae and the orientation of its jet stream are potential sources of remarkable imbalance of arch vessel perfusion especially with single jet stream cannulae. These effects are more pronounced with single jet stream cannulae. These results may have important clinical implications regarding perfusion of arch vessels during extracorporeal circulation.