Is there anyone who knows the word "vuṭṭhānaṃ"?

I guess so.

Uṭṭhāna=> Note. The form vuṭṭhāna appears for uṭṭh° after a vowel under the same conditions as vuṭṭhahati for uṭṭhahati (q. v.) gabbha — vuṭṭhānaṁ J i.114. See also vuṭṭh°, and cp. pariy°.

Uṭṭhāna (nt.) [fr. ut + ṣṭhā] 1. rising, rise, getting up, standing (opp. sayana & nisīdana lying or sitting down)
2. rise, origin, occasion or oppertunity for; as adj. (—°) producing
3. “rousing”, exertion, energy, zeal, activity, manly vigour, industry, often syn.

Vuṭṭha [pp. of vassati1] (water) shed, rained
*compare: genitive. dative. plural. Masculine. feminine. neuter. ānaṃ
*compare: accusative. Singular. Masculine. ānaṃ

Te ca hāvuso, āyusaṅkhārā abhaviṃsu te vedaniyā dhammā, na yidaṃ saññāvedayitanirodhaṃ samāpannassa bhikkhuno vuṭṭhānaṃ paññāyetha.

Here, it means “emerge”, as in “to enter into and emerge from a meditation”.