Research report
A research report is the sourced material a domain
dossier is synthesized from — generated on a plan and a cadence, one topic per file.
A report carries no confidence tags. Its bracketed markers say who might have
an incentive to shade a line; none of them says anyone checked it. To reach a score, a line has
to be drafted onto a candidate as unverified and pass the Verifier or the
Corroborator, like everything else.
Section care-pathway · Version 2026-09-01 · Cadence annual · Evidence class mixed · Sources 6 · Supersedes none
Domain: canine-equine-distal-limb-wounds · Scope: Public primary sources reachable by this repo's connectors, WebSearch and WebFetch.
Sourcing: Two single-source veterinary case-series findings add site-of-service counts
The domain dossier's §2 already establishes the coarse shape of this care pathway: canine NPWT runs from general practice or referral surgery toward increasing send-home use, while equine NPWT is described mostly as a days-to-weeks inpatient adjunct, with over a quarter of horses in the largest case series discharged before the treating team considered NPWT complete. That finding is not repeated here. This report instead extracts two things the dossier's own §2 case-series citations already supported but had not pulled out — a quantified count of how many dogs in the one canine send-home case series were actually discharged mid-treatment, and a wound-type breakdown for the equine case series — and adds one human/UK site-of-service-migration case series offered strictly as an analog. It also traces what the regulatory classification underneath this candidate's off-label human predicate already assumes about who operates the device day to day, independent of who is allowed to obtain it. A separate WebSearch/WebFetch effort to characterize US surgical/technician staffing capacity and a commercial rental-logistics model surfaced real material (an ACVS diplomate count, NAVTA's specialty-academy list, a veterinary NPWT rental vendor's own page) that this report deliberately does not cite as a source of record, because none carries a resolvable identifier — see §5.
_Baseline (v1). No prior version; this establishes the starting point for future diffs._
The dossier's §2 already cites the 7-dog free-skin-graft case series for its 100% graft-survival finding. The same case series also reports the discharge pattern directly: of the 7 dogs treated with a portable single-use device after full-thickness meshed skin grafts to the distal extremity, NPWT was provided for 4 to 7 days, and 5 of the 7 dogs were discharged from hospital during the treatment period — the device continued running at home rather than only in-hospital [single-source] [1]. That is a specific count for what the dossier's §2 described in general terms as "increasingly sent home."
The 42-horse equine case series the dossier already cites for its mean 11.5-day application duration also breaks the cohort down by wound type and treatment intent, detail the dossier's own §2 and §4 tables did not carry: wounds were 36% bony (15/42), 33% articular (14/42), 21% tenosynovial (9/42), 5% muscular (2/42) and 5% cutaneous (2/42), and NPWT was used to support first-intention healing preoperatively in 7% (3/42) or postoperatively in 17% (7/42), second-intention healing in 74% (31/42), and delayed primary closure in 2% (1/42) [single-source] [2]. Three-quarters of this cohort is second-intention wound management specifically — the same healing mode the dossier already names as predisposed to exuberant granulation and prolonged courses in horses, and a joint/bone-involving wound (69% of the cohort combined) plausibly compounds why a system left in place at a hospital, rather than sent home, is the pattern the dossier's §2 already documents for this species.
No veterinary source located this pass or in the dossier describes a formal discharge pathway analogous to what this candidate would need to build for horses. The closest precedent found is human and from the UK: a 2025 case series of 5 patients with open lower-limb wounds at a UK National Health Service facility used a single-use NPWT device specifically as "a bridge between hospital and community NPWT," reporting an average inpatient length-of-stay reduction of 20.2 days and a projected £12,350 savings in hospital costs per patient compared with patients who remained hospitalized until community NPWT became available [single-source] [3]. This is offered strictly as an analog for the shape of a site-of-service-migration program built around a single-use device — not as evidence about dogs, horses, or the US — and it is a 5-patient case series, not a controlled study, from a health system with no equivalent in veterinary medicine.
Two layers of the human FDA classification this candidate's off-label predicate already sits inside bear directly on site of service. 21 CFR 878.4780 classifies the "powered suction pump" (product code OMP, the canister-based predicate category) as a device "intended to be used to remove infectious materials from wounds or fluids from a patient's airway or respiratory support system," which "may be used during surgery in the operating room or at the patient's bedside" — a clinical/professional-setting framing at the base classification level [4]. A distinct, newer classification, 21 CFR 878.4783 ("negative pressure wound therapy device for reduction of wound complications," created by a 2021 FDA final order), covers powered suction pumps used with 878.4780-classified dressings for wound management generally, excluding organ-space wounds, and its Class II special controls require that "usability testing must demonstrate that intended users can correctly use the device, based solely on reading the instructions for use" [5] — the FDA's own special controls for this device category already anticipate operation by a non-professional user from the instructions for use alone. The 2021 final order that created that classification separately states that, "at the time of classification, negative pressure wound therapy devices for reduction of wound complications are for prescription use only" [6]. Read together: the human regulatory base this candidate's predicate already sits inside treats "someone other than a clinician operates the device day to day" as a tested design assumption, while still gating who may obtain it in the first place behind a prescriber — a split that has no veterinary-specific analog, since no veterinary prescription-gating or professional-oversight structure parallels it (dossier §6).
[1] PMID 27569833 — "Negative pressure wound therapy using a portable single-use device for free skin grafts on the distal extremity in seven dogs" — Australian Veterinary Journal (published 2016-09; accessed 2026-09-01). PMID 27569833 — https://pubmed.ncbi.nlm.nih.gov/27569833/ [peer-reviewed] [2] PMID 34670699 — "Use of Negative Pressure Wound Therapy in the Treatment of Limb Wounds: A Case Series of 42 Horses" — Journal of Equine Veterinary Science (published 2021-11; accessed 2026-09-01). PMID 34670699 — https://pubmed.ncbi.nlm.nih.gov/34670699/ [peer-reviewed] [3] PMID 40931370 — "Accelerating patient transitions from hospital to home in the United Kingdom with single-use negative pressure wound therapy: a discharge pathway" — Wounds: A Compendium of Clinical Research and Practice (published 2025-08; accessed 2026-09-01). PMID 40931370 — https://pubmed.ncbi.nlm.nih.gov/40931370/ (human population, UK jurisdiction) [peer-reviewed] [4] 21 CFR 878.4780, "Powered suction pump" — eCFR, via python3 -m connectors regulation 878.4780 --title 21 --jurisdiction US, run 2026-09-01 → status verified (issue 2026-08-27; accessed 2026-09-01). 21 CFR 878.4780 — https://www.ecfr.gov/current/title-21/section-878.4780 [federal-registry] [5] 21 CFR 878.4783, "Negative pressure wound therapy device for reduction of wound complications" — eCFR, via python3 -m connectors regulation 878.4783 --title 21 --jurisdiction US, run 2026-09-01 → status verified (issue 2026-08-27; accessed 2026-09-01). 21 CFR 878.4783 — https://www.ecfr.gov/current/title-21/section-878.4783 [federal-registry] [6] Federal Register document 2021-26741 (86 FR 70373), "Medical Devices; General and Plastic Surgery Devices; Classification of the Negative Pressure Wound Therapy Device for Reduction of Wound Complications" — Food and Drug Administration, Department of Health and Human Services (published 2021-12-10; accessed 2026-09-01, via python3 -m connectors policy 2021-26741 --expect "prescription device" --jurisdiction US). FR Doc. 2021-26741 — https://www.federalregister.gov/documents/2021/12/10/2021-26741/medical-devices-general-and-plastic-surgery-devices-classification-of-the-negative-pressure-wound [federal-registry]
Well established: Nothing in this report rests on ≥2 independent, non-affiliated primary sources — every substantive line is a single finding from a single source and is marked [single-source] where it is a case-series/study finding. [4], [5] and [6] are registry/federal primary text and are stated plainly as what the record itself says, per this repo's own convention for a registry fact. The dossier's own §2 finding (equine as inpatient adjunct, over a quarter discharged before NPWT was considered complete; canine trending toward send-home) is not re-derived or re-cited as new here; this report only adds granularity the dossier's own case-series citations already supported but had not extracted.
Thin: All three case-series lines ([1], [2], [3]) rest on exactly one source each. [3] is a 5-patient case series in a different species (human) and jurisdiction (UK), offered only as a structural analog and flagged as such everywhere it is used — it is not corroborating evidence for anything about dogs, horses, or the US.
Rescoped from class 3: None in this report. The dossier's own §9 already records "would veterinary surgeons switch from off-label human PICO/canistered systems to a purpose-built veterinary unit?" and "would owners pay several hundred dollars out of pocket?" as unanswered class-3 questions with either a twin (§5's abandonment record) or no twin at all; this report did not encounter a new class-3 question in its own searches and rescopes nothing further.
Out of scope: CPT descriptors, veterinary claims/EHR datasets, and a PatentsView-backed patent search were not attempted — none bears on care pathway or site of service and all three are already named out-of-scope in the domain dossier for other sections. CMS coverage (coverage E2402) and HCPCS (hcpcs E2402) connector calls were run and returned "no local cache" refusals per this repo's own instruction not to substitute a web search for those files (see data/README.md); this is also structurally moot for this domain, since no US veterinary payer exists (dossier §6).
Not searched vs. not found: A US or AAEP-specific quantified breakdown of equine practices by type (ambulatory-only, ambulatory-with-haul-in, specialty/referral) was searched for (web search) and a figure surfaced in search-result summaries attributed to an AAEP-AVMA member survey, but it was not independently retrieved from any AAEP or AVMA primary document this pass — every direct WebFetch attempt at avma.org and related pages returned empty content or was not reachable, and the figure is not used here for that reason. A CMS Local Coverage Article on NPWT suction pumps (A52519) was attempted directly and returned HTTP 403 — not retrieved. No ACVS or AAHA wound-management guideline document was located or fetched this pass, the same gap the dossier's own §4 and §10 already name as "not attempted." A query for referral-timing criteria between general practice and boarded surgeons for open/degloving wounds returned zero PubMed records — recorded as found-and-negative, not unsearched. Separately: an ACVS news release (2025-03-25) reporting 2,597 total board-certified diplomates, "approximately 68 percent small animal surgeons and 32 percent large animal surgeons," a NAVTA page listing 16 recognized veterinary technician specialty academies (none for wound care), and a US veterinary NPWT rental/support vendor's page describing a two-warehouse (Florida, Atlanta) rental-or-purchase model were all found and retrieved directly this pass, read in full, and are accurately summarized in this paragraph — but none is used as a source of record in §4 or cited with a numbered marker in §3, because none carries a resolvable identifier (PMID, NCT, K-number, CFR section, HCPCS code, DOI, CELEX, or FR Doc number) as this report's own sourcing rule requires. A later reader who wants this material re-added should re-source it against a primary document that does carry an identifier, rather than citing the association or vendor page directly.
[inference] None in this report. Every line above is either a direct quotation/count from a retrieved source or a plainly labeled structural analog; no synthesis beyond restating and combining the retrieved text is offered.
| Proposition | Evidence class | Resolvable identifier | Dossier section |
|---|---|---|---|
| In a retrospective case series of 7 dogs treated with a portable single-use NPWT device after full-thickness meshed skin grafts to the distal extremity, NPWT was applied for 4-7 days and 5 of the 7 dogs were discharged from hospital during the treatment period | 2 published | PMID 27569833 | care-pathway |
| In a retrospective case series of 42 horses treated with NPWT for limb wounds, wounds were classified as 36% bony (15/42), 33% articular (14/42), 21% tenosynovial (9/42), 5% muscular (2/42) and 5% cutaneous (2/42), with second-intention healing the indication in 74% (31/42) of cases | 2 published | PMID 34670699 | care-pathway |
| In a UK NHS case series of 5 patients with open lower-limb wounds, a single-use NPWT discharge pathway produced an average inpatient length-of-stay reduction of 20.2 days and a projected £12,350 savings in hospital costs per patient, versus patients who remained hospitalized until community NPWT was available | 2 published | PMID 40931370 | care-pathway |
| 21 CFR 878.4783's Class II special controls for a negative pressure wound therapy device for reduction of wound complications require that usability testing demonstrate intended users can correctly use the device based solely on reading the instructions for use, while the 2021 final rule creating the classification states such devices are for prescription use only | 1 registry | 21 CFR 878.4783; Federal Register document 2021-26741 (86 FR 70373) | care-pathway |