Is there any difference in perioperative characteristics or postoperative complications between overweight, normal-weight and obese patients in delayed DIEP reconstructions?

Figures & data

Table 1. Patient characteristics according to body mass index (N = 308).

	BMI < 25.0 (n = 104)		BMI 25.0–29.9 (n = 142)		BMI ≥ 30.0 (n = 62)		p-value
Age, years, Median (Md), Interquartile Range, Range)	53.5	(48–61; 27–71)	54	(47–60; 18–72)	52	(49–59; 35–72)	0.911
Age ≥ 60 years, n (%)	29	(28)	39	(27)	10	(16)	0.168
ASA category, n (%)							0.075
1	25	(24)	37	(26)	13	(21)
2	77	(74)	95	(67)	41	(66)
3	2	(2)	10	(7)	8	(13)
Smokers, n (%)	5	(5)	13	(9)	5	(8)	0.454
Antihypertensive drugs, n (%)							0.001
None	89	(86)	100	(70)	38	(61)
Yes	15	(14)	42	(30)	24	(39)
Radiation therapy, n (%)	44	(42)	81	(57)	30	(48)	0.072
Cardiovascular disease, n (%)	11	(11)	25	(18)	18	(29)	0.012
Diabetes mellitus, n (%)	0	(0)	5	(3)	4	(6)	0.026
Asthma, n (%)	24	(23)	32	(22)	15	(24)	0.984
Other diseases, n (%)	10	(10)	16	(11)	7	(11)	0.914
Prior abdominal surgery, n (%)							0.636
Yes	27	(26)	33	(23)	12	(19)
No	77	(74)	109	(77)	50	(81)

Differences between Body Mass Index groups were tested using Fisher’s exact test. ASA category: American Society of Anesthesiologists category. Antihypertensive drugs included angiotensin receptor blockers, calcium-channel blockers, beta-blockers, and diuretics.

Table 2. Perioperative characteristics according to body mass index (N = 308).

	BMI < 25.0 (n = 104)		BMI 25.0–29.9 (n = 142)		BMI ≥ 30.0 (n = 62)		p-value
Reconstruction time, Median (InterQuartileRange, Range)	284	(240–341; 136–570)	300	(249–340; 124–583)	320	(253–377; 122–560)	0.072
Reconstruction time > 340 min, n (%)	26	(25)	34	(24)	27	(44)	0.013
Hospital stay days, Md (IQR, Range)	5	(4–5; 3–6)	5	(4–5; 3–7)	5	(4–5; 4–9)	0.129
Estimated blood loss, Md (IQR, Range)	80	(50–120; 20–240)	92.5	(62–141; 20–500)	120	(60–203; 30–900)	0.002
Blood loss > 150 ml, n (%)	12	(11)	28	(20)	25	(40)	<0.001
Total fluids (ml), Md (IQR, Range)	4210	(3282–5204; 2018–6720)	3821	(3216–4732; 1210–7120)	4052	(3207–5063; 1763–6677)	0.319
Total fluids < 3200 ml, n (%)	24	(23)	34	(24)	14	(23)	1.000
Total urine output (ml), Md (IQR, Range)	2203	(1632–2742; 506–4405)	2041	(1521–2564; 557–4910)	2055	(1695–2556; 875–4050)	0.425
Urine output < 1600 ml, n (%)	25	(24)	39	(27)	11	(18)	0.337
Vasoactive drug used, n (%)							0.815
None	35	(34)	52	(37)	20	(32)
Yes	69	(66)	90	(63)	42	(68)

Differences between Body Mass Index groups were tested using Fisher’s exact test. ASA category: American Society of Anesthesiologists category. Vasoactive drugs used include phenylephrine, dobutamine, and noradrenalin.

Table 3. Detailed comparison of complications between BMI groups (N = 308).

	All groups (N = 308)	BMI < 25 (n = 104)		BMI 25–29.9 (n = 142)		BMI ≥ 30 (n = 62)
	n (%)	n	(%)	n	(%)	n	(%)	p-value
All complications								0.122
None	205 (67)	75	(72)	96	(68)	34	(55)
Minor complications	51 (17)	13	(12)	21	(15)	17	(27)
Major complications	52 (17)	16	(15)	25	(18)	11	(18)
Minor complications*								0.968
Seroma or minor wound problem treated without antibiotics	21 (41)	7	(41)	9	(43)	5	(38)
Wound problem requiring antibiotics	30 (59)	10	(59)	12	(57)	8	(62)
Major complications								0.494
Hematoma	11 (21)	3	(19)	7	(28)	1	(9)
Necrosis or wound problem requiring re-operation	19 (36)	6	(37)	7	(28)	6	(55)
Deep infection	5 (10)	0		3	(12)	2	(18)
Pulmonary embolism	5 (10)	3	(19)	2	(8)	0
Re-anastomosis	12 (23)	4	(25)	6	(24)	2	(18)

Differences between Body Mass Index groups were tested using Fisher’s exact test. * Of all complications, six occurred in the donor site (two in the overweight and four in the obese group). These complications were minor (three wound problems treated without antibiotics and three required per oral antibiotics). All other complications occurred in the reconstructed breast area.

Table 4. Patient and perioperative characteristics according to complications (N = 308).

	None (n = 205)		Minor (n = 51)		Major (n = 52)
	n	(%)	n	(%)	n	(%)	p
Age ≥ 60 years	59	(29)	12	(23)	7	(13)	0.068
ASA category							0.861
1	49	(24)	11	(22)	15	(29)
2	142	(69)	36	(71)	35	(67)
3	14	(7)	4	(8)	2	(4)
Smokers	17	(8)	3	(6)	3	(6)	0.850
Radiation therapy	106	(52)	24	(47)	25	(48)	0.798
Cardiovascular disease	36	(18)	10	(20)	8	(15)	0.834
Asthma	46	(22)	16	(31)	9	(17)	0.235
Other diseases	19	(9)	6	(12)	8	(15)	0.359
Antihypertensive drugs	48	(23)	17	(33)	16	(31)	0.232
Body mass index							0.122
<25	75	(37)	13	(25)	16	(31)
25–29	96	(47)	21	(41)	25	(48)
≥30	34	(17)	17	(33)	11	(21)
Reconstruction time > 340 min, n (%)	54	(26)	15	(29)	18	(35)	0.477
Bleeding > 150ml	35	(17)	12	(23)	18	(35)	0.022
Total fluids < 3200 ml	53	(26)	6	(12)	13	(25)	0.089
Urine output < 1600 ml	53	(26)	7	(14)	15	(29)	0.129
Vasoactive drug used							0.579
None	75	(37)	17	(33)	15	(29)
Yes	130	(63)	34	(67)	37	(71)

Differences between complication groups were tested using Fisher’s exact test. ASA category: American Society of Anesthesiologists category. Antihypertensive drugs included angiotensin receptor blockers, calcium-channel blockers, beta-blockers, and diuretics. Vasoactive drugs used include phenylephrine, dobutamine, and noradrenalin.

Table 5. Association of patient and perioperative characteristics on complications.

	Multivariable multinomial logistic regression
	No complications (n = 205)	Minor complications (n = 51)					Major complications (n = 52)
		Without interactions		With interactions			Without interactions		With interactions
	%	OR	(95% CI)	OR	(95% CI)	%	OR	(95% CI)	OR	(95% CI)	%
Age
≥ 60 years	98.7	0.84	(0.40–1.79)	0.67	(0.30–1.48)	1.3	0.38	(0.15–0.91)	0.32	(0.13–0.80)	0
<60years	94.3	1,00		1.00		3.0	1.00		1.00		2.6
Body mass index
≥30	85.5	2.59	(1.07–6.23)	0.76	(0.20–2.81)	12.9	1.02	(0.40–2.58)	0.54	(0.12–2.47)	1.6
25–29	97.2	1.27	(0.58–2.77)	1.31	(0.43–3.99)	0	1.09	(0.53–2.27)	1.58	(0.49–5.12)	2.8
<25	99.0	1.00		1.00		0	1.00		1.00		1.0
Radiation therapy
Yes	94.2	0.69	(0.36–1.32)	0.08	(0.01–0.66)	5.2	0.82	(0.43–1.56)	0.58	(0.17–1.92)	0.6
No	96.7	1.00		1.00		0	1.00		1.00		3.3
Blood loss
>150 ml	81.5	1.06	(0.46–2.44)	1.01	(0.41–2.48)	9.2	2.30	(1.09–4.82)	2.22	(1.03–4.78)	9.2
≤150 ml	99.2	1.00		1.00		0.8	1.00		1.00		0
Total fluids
<3200	98.6	0.45	(0.15–1.30)	0.40	(0.12–1.27)	0	0.91	(0.37–2.22)	0.91	(0.36–2.27)	1.4
≥3200	94.5	1.00		1.00		3.4	1.00		1.00		2.1
Total urine output
< 1600 ml	96.0	0.69	(0.25–1.91)	2.30	(0.50–10.5)	1.3	1.21	(0.51–2.88)	2.68	(0.71–10.1)	2.7
>1600 ml	95.3	1.00		1.00		3.0	1.00		1.00		1.7
Antihypertensive drugs
Yes	85.2	1.50	(0.71–3.15)	1.09	(0.54–2.22)	9.9	1.36	(0.64–2.89)	1.36	(0.63–2.94)	4.9
None	99.1	1.00		1.00		0			1.00		0.9
BMI ≥ 30*Radiation therapy	70.0			42.0	(3.54–497)	26.7			4.52	(0.67–30.7)	3.3
BMI25–29*Radiation therapy	100.0			8.75	(0.84–91.5)	0			1.23	(0.27–5.67)	0
BMI < 25*No radiation therapy	100.0			1.00		0			1.00		0

Univariable statistically significant variables forced to the model: age, Body Mass Index, blood loss, fluids, urine output, antihypertensive drugs, and radiation therapy. Also included in the model are: American Society of Anesthesiologists category (ASA), cardiovascular diseases, and reconstruction time. Interactions of BMI were modeled forward stepwise and results only for statistically significant (p < 0.05) interactions were shown in the table. Antihypertensive drugs included angiotensin receptor blockers, calcium-channel blockers, beta-blockers, and diuretics. Multivariable multinomial logistic regression analysis was used to predict complications. Reference for minor and major complications was no complications. Results were shown using odds ratios (OR) with 95% confidence intervals (CI) and predicted percentages of the observations in the subgroups (%).