Acts 1:18 and a question of usage (λάσκω)

Οὗτος μὲν οὖν ἐκτήσατο χωρίον ἐκ μισθοῦ τῆς ἀδικίας, καὶ πρηνὴς γενόμενος ἐλάκησεν μέσος, καὶ ἐξεχύθη πάντα τὰ σπλάγχνα αὐτοῦ.

Now this man acquired a field with the reward of his unjust deed, and falling headfirst he burst open in the middle and all his intestines gushed out.

This is a vivid and rather horrifying description of Judas's end; it is the subject of much discussion, which the reader can find at the biblehub.com site, under 'Commentary' for Acts 1:18. 

That οὗτος refers to Judas must be inferred from the context of previous verses. 

Οὗτος is the 'near' demonstrative pronoun, meaning something like 'this, the person/thing that we were just talking about'.  The 'far' demonstrative pronoun (ἐκεῖνος, η, ο) is more like 'that', 'the person/thing over there or further away'.

There are four actions in this verse:

1  Judas acquired or possessed a field: ἐκτήσατο

Ἐκτήσατο is parsed as the 3-S (subject: Judas) aorist middle indicative of κτάομαι ('I acquire, purchase, possess').  I would consider κτάομαι a deponent verb, in that it has no active forms; the meaning makes sense as a middle - 'I do something (for myself)'.

 The neuter noun χωρίον, 'field, piece of land', is the direct object of ἐκτήσατο. 

2  Judas fell headlong:  πρηνὴς γενόμενος

Γενόμενος is not an indicative verb form; it is the masculine singular nominative form (referring again to Judas) of the aorist participle of γίνομαι.  

Πρηνής is found only here in the NT; a hapax legomenon.  It means something like 'headfirst' or 'headlong'.  It has been suggested that the English 'prone' is etymologically related, but that seems to be questionable. 

3  Judas burst open in the middle:  ἐλάκησεν μέσος

Ἐλάκησεν is another hapax legomenon; the 3-S (Judas again), aorist active indicative, of λάσκω.

Here we have a question.  Λάσκω is used by classical authors, from Homer down.  It has various uses, including:  

 - to sound, resound:   λάκε δ᾽ ἀσπὶς - 'the shield rang', Iliad 20.277

 - to screech, bark (of animals): ἔνθα δ᾽ ἐνὶ Σκύλλη ναίει δεινὸν λελακυῖα - 'there dwells Scylla, yelping terribly', Odyssey 12.85

 - to say, announce, proclaim:  περίφρονα δ᾽ ἔλακες - 'you speak arrogantly', Aeschylus, Agamemnon, 1426

There is apparently no classical use suggesting a body breaking open, nor - as best I can tell - is the verb found in the Septuagint.

Commentaries have suggested a variety of things, including that Judas's body burst open 'with a loud sound', which seems odd at best.  I suggest 'he screamed from deep within' as a possible alternative.  

4  His internal organs spilled out:  ἐξεχύθη πάντα τὰ σπλάγχνα αὐτοῦ

Here the subject is not Judas, but his internal organs (τὰ σπλάγχνα αὐτοῦ).  Ἐξεχύθη is parsed as 3-S, aorist active indicative, ἐκχέω - 'I pour out'.  I believe that ἐξεχύθη is singular rather than plural because of τα ζώα τρέχει, where neuter plurals can use a singular verb.