Time to recovery PPNI (secondary outcome)
From various definitions of persistent phrenic nerve injury (beyond
procedure/discharge), we established the definition as impairment of
diagrammatic stimulation beyond the time of hospitalization. In 37
studies with 194 cases it was decided that after recalculating those
occurrences after the procedure but not after hospitalization to define
that group as transient PNI. Eighty-one persistent PNI after CB-1 and
113 after CB-2 generation were noted. In the CB-1 group, almost half of
the nerve injuries (40 PPNI; 49,4%) were associated with 23 mm,
although the use of CB1-23 mm accounted for almost a quarter of the
total first generation (n = 1164; 25.9%). In CB-2, the use of 23 mm
significantly decreased to n = 192 (3.3%) after which the incidence
with 23 mm became statistically insignificant. In CB-2, CMAP usage
became a marker. Seventy-three (64.6%) PPNI occurred without the CMAP,
and 40 (35.4%) occurred with CMAP use (p < 0.05).
We investigated the time to recovery based on the registries. The
information was found in 27 studies by observing 150 PPNI, 66 from CB-1
and 84 from CB-2. Precise data with time to resolution were collected
from 138 PNI and divided into persistent PNI-CMAP and persistent PNI
non-CMAP protection groups. The median time to recovery in the
persistent PNI with CMAP group was three months (standard deviation
[SD] 3.45; 95%CI 1.9–4.1) while without CMAP protection, this time
was prolonged to six months (SD 4.1; 95%CI 5.2–6.8) with statical
significance based on Wilcoxon Peto’s log-rank test (p = 0.012) as shown
in Figure 5. Only 12 results were described as unresolved ranging over
24 months beyond the observation period. The longest time of observation
of unresolved persistent PNI reach over 36 month [46]. Detailed
information of PNI follow-up can be found in the supplemental
publication material.