At a recent AOJS meeting Jessica Grant said in your name that Metzizah should only be done with a tube.
Would you be kind enough to provide details because many different things have been said in your name.
a. I have never said or wrote that metzizah should only be done with a tube.
b. In my understanding I am following the Chatam Sofer and most of the Litvishe Gedolim, which accepted that the rule of metzizah was indicated by chaza"l as a medical rule to prevent danger.
Over 750 years ago, Rabbi Yaakov Hagozer (Zichron Brit L'Rishonim, Berlin 5652, page 20) had a similar opinion and added some interesting medical explanation:
“Metzitza… How? After the incision and splitting the membrane, one immediately brings the penis into his mouth and sucks out blood with all one’s strength, because if he does not suck, the blood will clot in the top of the penis and this is dangerous. It is similarly said in chapter Rabbi Eliezer [the 19th chapter of Masechet Shabbat]: ‘Rav Pappa said: A mohel who does not perform metsitsa endangers the baby and is dismissed’ because the blood will clot within the penis and this is dangerous."
(The "top of the penis" here cannot mean the 'urethral meatus', where cloted blood can be easily removed without metzizah. The right understanding here is: the 'blood vessels within the distal parts of the penis')
c. Translation of the above statement to modern medical language:
Immediately after incising or injuring an artery, the arterial walls contract and occlude, or at least reduce, continued flow of blood. The constriction is caused in part by a nervous reflex and principally by a local reaction of the smooth muscle layer of the artery. This apparently leads to induction of an action potential (resulting in contraction) that can travel along several centimetres of the arterial wall. [Guyton A.C., Textbook of Medical Physiology, 5th edition, (W.B. Saunders Co., Philadelphia, 1976), p.99]
Excising the prepuce can, therefore, cause a temporary occlusion in the dorsal arteries as a result of the localised reaction to the incision of the arterioles of the prepuce as these branch off of the dorsal arteries. (See section 12 of my article: A New Insight to Mysterious Talmudic Rulings: Metziza and Bathing in Warm Water in the Performance of Jewish Ritual Circumcision – A Modern Explanation for Their Institution, and its Clinical, Halachic, and Legal Significance, Jewish Medical Ethics Vol. V, No. 2 July 2006, for a discussion of the penile blood supply)
This transient arterial occlusion caused by muscle contraction continues to develop into a more enduring blockage as the hindered and stationary blood begins to clot. The primary stage in the pathological process is hypoxia which can easily be identified by simple visual inspection of the glans without any need to be familiar with the knowledge of modern medicine. Only an immediate resolution of that occlusion can stymie the local process of coagulation, which can turn the transiently occluded artery into a permanently blocked artery. Indeed, were this artery to become fully obstructed and no longer supply the glans with blood, it would generally have no effect on the alternative blood supply of the glans, which comes from the well-protected and padded urethral arteries. However, in those instances where a congenital anomaly affects the urethral arteries, a transient blockage of the dorsal arteries can cause severe hypoxia of the glans. If the arterial obstruction becomes more permanent, the baby may lose his glans and it may even become a life-threatening situation.
Performing metsitsa immediately after circumcision, on the other hand, lowers the internal pressure within the tissues and blood vessels of the glans, thus raising the pressure gradient between the blood vessels at the base of the penis and blood vessels at its distal end – the glans as well as the excised arterioles of the prepuce which branch off of the dorsal arteries.This increase in pressure gradient ( by a factor of 4 to 6 !) can resolve an acute temporary occlusion and restore blood flow to the glans, thus significantly reducing both the danger of immediate, acute hypoxia and the danger of developing a permanent obstruction by means of coagulation. The indication that the temporary occlusion have been resolved is that "the blood in the further reaches (= the proximal dorsal artery) will be extracted" as the Rambam has stated.
d. By this understanding it is easy to conclude that in most cases the medical effect of metzizah b'peh is much greater then that with a tube.
Therefore the only discussion is when, according to the halachic principles, a danger should contraindicate metzizah b'peh.
e. From the halachic rules in Yevamot 64b we can draw some conclusions.
The sages initiated a law that forbade not only circumcising a baby whose two brothers had died from a Brit Milah, but also a baby whose two cousins from his mother’s side had died following a circumcision. They feared that his maternal cousins carried some unproven medical disorder and that therefore he was at a significant risk of dying from the procedure. This rule exists even though chaza"l had no proof to the assumption that the mother is the cause to the baby's death after the circumcision.
According to this principle of chaza"l, whenever any mohel has at least two cases of Herpes infected babies shortly after his metzizah b'peh, this mohel should not be allowed to continue this procedure, even if we have no clear proof that he is the cause of the infection.
This is my opinion regarding metzizah b'peh.