Clinical and radiological outcome following pneumothorax after endoscopic lung volume reduction with valves

Figures & data

Table 1 Baseline characteristics of all patients treated by valves

Baseline clinical measures	n	Mean ± SD	Min	Max
VC (L)	381	2.4±0.65	0.6	4.9
VC (% predicted)	378	69.2±12.37	21	118.7
FEV1 (L)	381	0.8±0	0.3	2.1
FEV1 (% predicted)	380	30.1±0.92	11.7	74.2
RV (L)	379	5.7±0.35	3.1	9.2
RV (% predicted)	380	261.7±21.4	143.5	523
TLC (L)	378	8.7±1.01	5.1	243.1
TLC (% predicted)	380	139.2±12.7	89.9	232
6-MWT (m)	343	272.3±110.3	30	490
mMRC (points)	309	2.8±1.4	0	4

Abbreviations: SD, standard deviation; VC, vital capacity; FEV₁, forced expiratory volume in 1 second; RV, residual volume; TLC, total lung capacity; 6-MWT, 6-minute walk test; mMRC, modified Medical Research Council; Min, minimum; Max, maximum.

Table 2 Distribution of treated target lobe

Target lung area	Target lobe of valve placement (n=381)		Advent of pneumothorax related to target lobe (n=70)
	n	% (in relation to total number treated)	n	% (in relation to number treated per target lobe)
Right upper lobe	46	12	7	15.2
Right upper lobe/middle lobe	39	10.5	2	5.1
Middle lobe	1	0.3	0	0
Right lower lobe	54	14.1	8	14.8
Right lower lobe/middle lobe	1	0.3	0	0
Segment 6 right	1	0.3	0	0
Left upper lobe	83	21.7	25	30.1
Left lower lobe	155	40.6	28	18.1
Upper lobes bilateral	1	0.3	0	0

Figure 1 Multi-detector CT.

Note: Chest tube insertion because of pneumothorax following valve placement in the left upper lobe.
Abbreviation: CT, computed tomography.

Table 3 Clinical outcome of all patients 3 months recovering after pneumothorax

Clinical outcome measures	All patients with pneumothorax (n=70; baseline–3 months following pneumothorax)
	n	Mean ± SD	P-value
ΔVC (mL)	53	28±494	0.676
ΔVC (% predicted)	53	1.7±14.7	0.414
ΔFEV1 (mL)	53	55±148	0.009
ΔFEV1 (% predicted)	53	2.0±5.3	0.007
ΔRV (mL)	50	−390±964	0.006
ΔRV (% predicted)	50	−23.0±43.3	0.001*
ΔTLC (mL)	51	−348±876	0.007
ΔTLC (% predicted)	51	−7.1±15.8	0.002
Δ6-MWT (m)	42	13.9±72.9	0.223
ΔmMRC (points)	38	−0.2±1.3	0.400

Note:

* Imputation analysis revealed statistical significance.

Abbreviations: SD, standard deviation; VC, vital capacity; FEV₁, forced expiratory volume in 1 second; RV, residual volume; TLC, total lung capacity; 6-MWT, 6-minute walk test; mMRC, modified Medical Research Council.

Table 4 Clinical outcome of all patients with pneumothorax but without lobar atelectasis 3 months after recovering from pneumothorax

Clinical outcome measures	All patients with pneumothorax, but without atelectasis (n =48; baseline–3 months following pneumothorax)
	n	Mean ± SD	P-value
ΔVC (mL)	34	−51±493	0.598
ΔVC (% predicted)	34	−1.1±14.1	0.449
ΔFEV1 (mL)	34	39±142	0.115
ΔFEV1 (% predicted)	34	1.3±4.9	0.119
ΔRV (mL)	32	−203±835	0.179
ΔRV (% predicted)	32	−15.9±34.0	0.013
ΔTLC (mL)	32	−237±805	0.107
ΔTLC (% predicted)	32	5.1±12.8	0.032
Δ6-MWT (m)	26	15.4±75.5	0.308
ΔmMRC (points)	24	−0.4±1.0	0.846

Abbreviations: SD, standard deviation; VC, vital capacity; FEV₁, forced expiratory volume in 1 second; RV, residual volume; TLC, total lung capacity; 6-MWT, 6-minute walk test; mMRC, modified Medical Research Council.

Figure 2 Response rate for FEV₁ and 6-MWT.

Notes: (A) A bar chart showing the response rate for FEV₁ change with a bar for each unique individual patient (n=53). Light gray denotes no atelectasis at any time. Dark gray denotes evidence of atelectasis at any time point. Dark gray/dotted represents persistent atelectasis. MCID threshold: improved, FEV₁ >100 mL; declined, FEV₁ >−100 mL. (B) A bar chart showing response rate for 6-MWT change with a bar for each unique individual patient (n=42). Light gray denotes no atelectasis at any time. Dark gray denotes evidence of atelectasis at any time point. Dark gray/dotted represents persistent atelectasis. MCID threshold: improved, 6-MWT >26±2 m; declined, 6-MWT >−26±2 m.
Abbreviations: FEV₁, forced expiratory volume in 1 second; MCID, minimal clinically important difference; 6-MWT, 6-minute walk test.

Table 5 Clinical outcome 3 months after recovering from pneumothorax of all patients with pneumothorax and lobar atelectasis

Clinical outcome measures	All patients with pneumothorax and atelectasis (prior/during and following pneumothorax; n =28; baseline–3 months following pneumothorax)
	n	Mean ± SD	P-value
ΔVC (mL)	19	170±475	0.136
ΔVC (% predicted)	18	6.9±14.7	0.062
ΔFEV1 (mL)	19	82±158	0.036
ΔFEV1 (% predicted)	19	3.3±5.8	0.023*
ΔRV (mL)	18	−721±1.107	0.013
ΔRV (% predicted)	19	−35.1±54.5	0.012
ΔTLC (mL)	18	−547±983	0.030
ΔTLC (% predicted)	19	−10.5±19.9	0.034
Δ6-MWT (m)	16	11.5±70.9	0.526
ΔmMRC (points)	14	−0.4±1.7	0.374

Note:

* Imputation analysis revealed statistical significance.

Abbreviations: SD, standard deviation; VC, vital capacity; FEV₁, forced expiratory volume in 1 second; RV, residual volume; TLC, total lung capacity; 6-MWT, 6-minute walk test; mMRC, modified Medical Research Council.