Proposed Classification of Incision Complications: Analysis of a Prospective Study on Elective Open Lower-Limb Revascularization

Abstract

Background:

Incision complications (IC) have a significant impact on procedure-related morbidity after lower-limb revascularization. One of the most studied IC is surgical site infection (SSI). Reporting these complications in a uniform way is crucial to evaluate treatment approaches. The aim of this study was to propose a comprehensive classification of IC and apply it to compare SSI with other IC in a trial on elective open lower-limb revascularization procedures.

Methods:

Two hundred twenty-three eligible patients undergoing elective unilateral inguinal and infra-inguinal arterial vascular surgery were extracted from a randomized controlled trial on incisional negative-pressure wound therapy (NPWT) on inguinal vascular surgical incisions. The IC were classified by grades of severity (grade 0–6) that focused on IC-related consequences such as out-patient treatment (grade 1), prolonged in-patient treatment (grade 2), re-admission (grade 3), and re-operation (grade ≥4). An SSI was defined by the ASEPSIS score criteria.

Results:

An SSI was diagnosed in 63 patients (28.3%). Thirty-five of 160 patients (21.8%) not suffering from SSI underwent IC treatment. Treatment for IC was recorded for 25/144 patients (17.4%) with satisfactory site healing as judged by the ASEPSIS score. The median incision-related in-hospital stay in those with SSI (n = 79) and disturbed healing (n = 16) according to the ASEPSIS score was 13 days in both groups (p = 0.53). Five patients had peri-vascular SSI (IC grade 4 n = 4; grade 5 n = 1). The proposed classification of IC and the ASEPSIS score correlated highly (r = 0.77; p < 0.001). Inter-rater reliability for IC grading was substantial for three investigators with different levels of experience (k = 0.81, 0.71, and 0.70).

Conclusions:

The proposed incision classification suggests a comparable clinical significance of vascular IC in terms of IC-related in-patient stay, whether there was a surgical site infection or not. This classification system requires external validation.

Incision complications (IC) can occur after any type of surgical procedure and carry different degrees of morbidity and death. Peripheral vascular surgery carries a large burden of IC [1]. Reporting these complications in a uniform, clear fashion is important to evaluate different treatment approaches and ensure the quality of care for patients. Although a classification for general operative and post-operative complications was established by Clavien et al. [2], a classification for IC does not exist. In their revised classification [3], Clavien et al. describe a comprehensive system for reporting surgical and non-surgical peri-operative complications. Because non-surgical complications, such as cardiac and respiratory issues, are taken into account, this classification might be well suited for comparing overall outcomes between centers when not only surgical but also other complications are of interest. However, it is less well suited when attempting to evaluate IC specifically.

Among the most common IC are seroma, hematoma and lymphocele formation, surgical site dehiscence, and surgical site infection (SSI). These entities often coexist, and their distinction from one another, such as between seroma and lymphocele, can be difficult and impractical. Of these entities, SSIs have been one of the most studied complications, and their impact on healthcare cost and patient outcomes is well established [4]. The impact of other IC is much less studied and potentially underestimated. Sites exhibiting similar features and requiring treatments similar to SSI might be under-reported if their features do not meet those of SSI completely. Lymphorrhea, for instance, is regularly managed with open negative-pressure wound therapy (NPWT) and antibiotics, sometimes used as a prophylactic regimen in the course of the treatment. The same treatment often is used to treat severe SSI. A classification of IC therefore should be based on the severity and consequences of complications and less on their sometimes less well-distinguishable etiologies. This was stressed in a paper by Wilson et al. [5], where major variation in the estimated percentage of SSI, using, among others, the Centers for Disease Control and Prevention (CDC) and ASEPSIS score definitions of SSI, prompted the authors to doubt that a meaningful comparison between centers could be accomplished. Furthermore, it should be applicable to all types of primary incisions and eliminate the need for subjective interpretation of severity. Medical therapy should not directly influence the grading, as this, too, contains subjective aspects, such as the decision to treat with antibiotics. The time point at which the grading is carried out should be modified depending on the surgical field and procedure it is applied to.

The first aim of this study was to propose a classification of IC that ensures simple and accurate reporting after elective open lower-limb revascularization procedures. Secondly, it intended to clarify whether complications not classified as SSI carry a similar morbidity as SSI.

Patients and Methods

Study population and setting

This exploratory cohort study was carried out at Vascular Center, Malmö, Skåne University Hospital, a tertiary referral center in the southern part of Sweden. The data utilized were collected prospectively from eligible patients in a randomized controlled trial examining the effects of incisional NPWT on inguinal vascular surgical incisions (INVIPS trial)[6], including those who were not randomized during the same time period. All lower-extremity vascular incisions were evaluated. The INVIPS trial was approved by the Research Ethics Board of Lund University, whereas the follow-up of non-randomized patients was conducted as a quality control investigation and therefore was exempt from ethical board requirements. Eligible were all adult patients subject to elective open lower-limb arterial revascularization procedures at Vascular Center Malmö between November 2013 and February 2019. The follow-up period of long-term data including amputation-free survival ended in May 2019. Only unilateral procedures were included to be able to evaluate incision morbidity for each patient adequately.

Incision surveillance

Incisions were assessed at the standardized follow-up visits by nurses and physicians one month post-operatively at the center's out-patient clinic, according to the Swedish Vascular Registry's (Swedvasc) requirements. An additional IC registration based on the patient's medical records was conducted at four months post-operatively. Cases with mild surgical site complications usually were referred to general practitioners responsible for the respective patients, whereas more severe cases were followed up at the out-patient clinic and, when required, admitted to the center's in-patient ward. The SSIs were defined primarily by the modified ASEPSIS score criteria and definitions [7] with additional reporting by the revised criteria of the CDC [8] and a maximum surveillance period of 90 days post-operatively.

Definitions

Disturbed healing existed if an ASEPSIS score above ten points was recorded. Twenty-one points constituted an SSI. The length of in-patient treatment secondary to incision issues was seen as a surrogate for incision morbidity. An in-hospital stay of more than two times the median time for comparable procedures constituted prolonged in-patient treatment. This applied in this study for a hospital stay of 11 days or more for femoral thrombendarterectomy (TEA) with and without simultaneous iliac stenting, and in-patient treatments of at least 17 days for bypass operations.

Proposed classification of incision complications

Grade 0 was defined as uneventful healing with no additional visits to any providers of healthcare.

Grade 1 entailed incision problems that require any number of unscheduled treatments at out-patient facilities but without the need for hospitalization.

Grade 2 described IC requiring a prolonged in-patient stay, defined as two times the median duration of hospitalization for comparable operations, at least in part secondary to incision issues.

Grade 3 applied to cases requiring that a patient be re-admitted for exclusively conservative incision treatment secondary to an IC after having been discharged after the primary operation. Starting NPWT without revision of the surgical site and without intensive care was permitted under this grade.

Grade 4 characterized cases where IC led to surgical site revisions after re-admission.

Grade 5 described cases requiring intensive care or resulting in serious complications, such as major amputations, secondary to IC.

Grade 6 was used in case of a fatal outcome as a result of IC.

As was deduced from a previous report [6], late incision complications typically do not arise past the third month after the index procedure. To ensure that even extraordinarily late presenting complications were registered, grading was performed at one and four months post-operatively. The highest grade that an incision received during the follow-up period was recorded. To ensure that cases with IC that resulted in the patient's demise would not be lost, all cases that did not reach the four-month mark were given the highest grade previously recorded. Inter-rater and test–retest reliability were assessed for the three case reviewers.

Classification of SSI severity

The depth of tissue involvement in confirmed infections, including cases with foreign-material vascular grafts, were classified according to the CDC system [9] as superficial, deep, or organ/space.

Inter-rater and test–retest reliability

Three case reviewers, consisting of an attending physician in vascular surgery, a resident in vascular surgery, and a post-graduate Year One intern, each received a data file with the patients' identification numbers, procedure dates and types, as well as a table outlining the IC grading system (Supplementary Digital Content 1). The case reviewers had no access to the database containing previously collected data on randomized patients in the controlled trial. All case reviewers examined the electronic patient records and carried out the site grading at the one- and four-month mark after the procedure. The reviewers' files subsequently were merged and evaluated.

Apart from inter-rater and test–retest reliability measurements, the grading of IC presented in this study was performed by the principal investigator.

Statistical analysis

Data management and statistical analysis were carried out using SPSS Statistics for Macintosh, V. 25.0 (IBM, Armonk, NY, USA).

To characterize the groups of patients suffering from different grades of IC, detailed descriptive parameters were gathered and evaluated. Differences in proportions were analyzed with χ² or Fisher exact test in case of two ordered groups. In case of more than two ordered groups, linear-by-linear association was utilized. Variables that were of a continuous nature were expressed in median and interquartile range (IQR) and group difference analyzed using the Mann-Whitney U test in case of two, and the Jonckheere-Terpstra test when three, ordered groups were compared. P values <0.05 were seen as significant.

The Spearman rank correlation coefficient was used when analyzing rank correlation between ordinal variables. The Wilcoxon signed-rank test was applied when analyzing repeated measurements of ordinal data. Inter-rater and test–retest reliability were assessed using the Cohen κ coefficient. As a rule of thumb, κ coefficients were interpreted as having no agreement if zero, having none to slight agreement if between 0.01 and 0.20, as fair in case of values between 0.21 and 0.40, as moderate when between 0.41 and 0.60, as substantial when between 0.61 and 0.80, and as almost perfect if between 0.81 and 1.00.

To explore the possibility that skewness might exist in the grading of the proposed classification, the data set was scrutinized to identify both floor and ceiling effects. These were confirmed if more than 15% of patients ended up in either the lowest or highest grades possible, respectively [10].

Results

Patient characteristics

Two hundred twenty-three patients were included in the analysis. Baseline characteristics of patients suffering from different grades of IC are outlined in Table 1.

Table 1.

Incision Complication Grading in Relation to Baseline Characteristics

	Grade 0	Grade 1	Grade 2–6	p
No of patients	127	45	51
Median age (y) (IQR)	72 (66–77)	70 (65–75)	71 (66–77)	0.48
Male gender (%)	87 (68.5)	33 (73.3)	38 (74.5)	0.39
Cerebrovascular disease (%)	22 (17.3)	7 (15.6)	11 (21.6)	0.58
Arterial hypertension (%)	101 (79.5)	37 (82.2)	42 (82.4)	0.63
Ischemic heart disease (%)	57 (44.9)	15 (33.3)	23 (45.1)	0.79
Median BMI (kg/m²) (IQR)	25 (22–28)	25 (23–29)	26 (23–31)	0.13
Current smoker (%)	34 (26.8)	18 (40)	10 (19.6)	0.60
Atrial fibrillation (%)	19 (15)	5 (11.1)	5 (9.8)	0.32
Diabetes mellitus (%)	46 (36.2)	20 (44.4)	20 (39.2)	0.58
Previous ipsilateral inguinal surgery (%)	40 (31.5)	8 (17.8)	14 (27.5)	0.38
Previous vascular surgery (%)	49 (38.6)	19 (42.2)	29 (56.9)	0.033
Ipsilateral foot wound (%)	37 (29.1)	11 (24.4)	17 (33.3)	0.70
Medication (%)
Anticoagulant	19 (15)	5 (11.1)	8 (15.7)	0.98
Aspirin	98 (77.2)	36 (80)	44 (86.3)	0.18
Steroids	7 (5.5)	2 (4.4)	7 (13.7)	0.087
Indication (%)
Lower leg ischemia
Claudication	55 (43.3)	19 (42.2)	18 (35.3)	0.35
Critical limb ischemia	65 (51.2)	22 (48.9)	31 (60.8)	0.31
Rutherford class				0.61
0	7 (5.5)	4 (8.9)	2 (3.9)
1	4 (3.1)	0	8 (3.6)
2	24 (18.9)	10 (22.2)	39 (17.5)
3	27 (21.3)	9 (20)	45 (20.2)
4	30 (23.6)	12 (26.7)	57 (25.6)
5	33 (26)	9 (20)	58 (26)
6	2 (1.6)	1 (2.2)	3 (1.3)
Aneurysmal disease (%)
Popliteal aneurysm	5 (3.9)	3 (6.7)	2 (3.9)	0.87
Femoral aneurysm	2 (1.6)	1 (2.2)	0	0.49

BMI body mass index; IQR = interquartile range.

Incision complications

Of the 223 patients, at the four-month follow-up mark, 63 (28.3%) suffered from SSI. Among patients not found to have an SSI (ASEPSIS score <21; n = 160), 35 (21.8%) underwent treatment for IC, 26 (16.3%) in an out-patient setting (grade 1) and 9 (5.6%) in in-hospital care (grade 3 or 4), of which three patients (1.9%) went through redo-operations of their incisions (grade 4) (Table 2). Of 223 patients, 16 suffered from disturbed site healing (ASEPSIS 11–20) without their incision being considered infected. Patients with SSI (n = 63) were found to have similar accumulated median incision-related length of in-hospital treatment as patients suffering from disturbed healing only (13 days [IQR 8–26] versus 13 days [IQR 5.5–21], respectively; p = 0.53).

Table 2.

Incision Complication Grading in Relation to ASEPSIS Score in 223 Patients

Severity grade (%)	Complication?
	(ASEPSIS Score >10)
	Yes (N = 79; 35.4%)		No (N = 144; 64.6)
	SSI N = 63 (79.7)	No SSI n = 16 (20.3)	No (N = 144; 64.6)
0	2 (3.2)	6 (37.5)	119 (82.6)
1	19 (30.2)	7 (43.8)	19 (13.2)
2	8 (12.7)	0	1 (0.7)
3	11 (17.5)	2 (12.5)	3 (2.1)
4	21 (33.3)	1 (6.3)	2 (1.4)
5	2 (3.2)	0	0
6	0	0	0
Median (IQR) inpatient stay during index procedure (d)	8 (6–17)	11.5 (5–21)	6 (5–8)
Median inpatient total stay^a (d) (IQR)	13 (8–26)	13 (5.5–21)	6 (5–8)

Of index procedure and additional in-patient treatment related to complications within four months post-operatively.

IQR = interquartile range.

Satisfactory incision healing was observed in 144 of 223 patients (64.1%) (ASEPSIS score <11) after four months of follow-up, and 25 (17.4%) of them underwent treatment for IC. Re-admission for IC was seen in five patients (3.5%; grade 3 or 4), and two of them (1.4%) were re-operated on for their IC (grade 4) (Table 2).

The proposed classification of IC correlated highly with SSI outcome, both according to ASEPSIS score (r = 0.77; p < 0.001) and the CDC criteria (r = 0.76; p < 0.001).

Surgical site infections and foreign-material vascular grafts

Foreign-material vascular grafts were used in 94/223 procedures (42.6%). An SSI was seen in 19/94 (20.2%) compared with 44/129 (34.1%) in patients not having foreign-material grafts (p = 0.025). Synthetic grafts tended to have shorter mean procedure times than non-synthetic vascular reconstructions, 180 (IQR 142–226) minutes versus 196 (IQR 156–254) minutes, respectively (p = 0.08). Patients undergoing reconstructions with non-synthetic material tended to have a greater IC burden (IC grade 0 n = 68, grade 1 n = 27, grade 2 n = 7, grade 3 n = 7, grade 4 n = 18, grade 5 n = 2) than patients with foreign-material grafts (IC grade 0 n = 59, grade 1 n = 18, grade 2 n = 2, grade 3 n = 9, grade 4 n = 6) (p = 0.08).

Peri-vascular infection was seen in five patients, four of whom received grade 4 and one grade 5 according to the proposed IC classification. Newly inserted foreign graft material was present in 19/63 patients (30.2%) with SSI (bovine pericardial patch 12/19 [63.2%], polytetrafluoroethylene 5/19 [26.3%], and polyethylene terephthalate [Dacron] 2/19 [10.5%]). Of these 19 patients, eleven (57.9%) had superficial problems (IC grade 0 n = 1, grade 1 n = 5, grade 2 n = 1, grade 3 n = 4), seven (36.8%) deep (IC grade 2 n = 1, grade 3 n = 1, grade 4 n = 5), and one (5.3%) peri-vascular (IC grade 4 n = 1) SSI according to the CDC classification.

NPWT compared with conventional dressings

Significantly lower SSI rates were observed in patients treated with incisional NPWT than with other dressings using both the ASEPSIS score (18/93 [19.4%] versus 45/130 [34.6%; p = 0.016) and CDC criteria (19/93 [20.4%] versus 48/130 [36.9%]); p = 0.011).

High-grade IC were similar in both groups (grade 2–6, NPWT n = 18/93 [19.4%] versus non-NPWT 33/130 [25.4%]); p = 0.33).

Incision complication grading in relation to baseline and peri-operative data

Baseline characteristics (Table 1) and peri-operative data (Table 3) in relation to individual grades of severity of IC showed that patients suffering from more severe IC (grade 2–6) more frequently had a history of previous vascular surgery (p = 0.033), pre-operative anemia (p = 0.0325), and a longer median in-patient stay after the index procedure (p = 0.0325). The proportion of femoral TEA was highest (p = 0.0435) in patients not suffering from IC (grade 0), whereas a trend (p = 0.083) toward a larger proportion of femoropopliteal bypass procedures was noted among patients with severe IC (grades 2–6).

Table 3.

Incision Complication Grade in Relation to Peri-Operative Data

	Grade 0	Grade 1	Grade 2–6	p
No. of patients	127	45	51
Pre-operative
Anemia (%)	51 (40.2)	21 (46.7)	30 (58.8)	0.025
Median BAC in g/L (IQR)	38 (35–41)	38 (36–41)	37 (34–39)	0.055
Median GFR in mL/min/1.73m² (IQR)	67 (52–83.4)	73 (61–84)	64 (42–84)	0.34
Median BGC in mg/dL (IQR)	8 (6.3–9.7)	7.6 (6.2–9.5)	8.3 (7.1–10.4)	0.26
ASA score 1/2/3/4	0/2/122/4	0/0/45/0	0/0/51/0
Intra-operative
Type of anesthesia (general/regional/local)	120/4/3	43/2/0	51/0/0
Procedure (%)
Femoral TEA	63 (49.6)	17 (37.8)	17 (33.3)	0.035
Femoral TEA and iliac artery stent	27 (21.3)	14 (31.1)	12 (23.5)	0.056
Femoropopliteal bypass	34 (26.8)	12 (26.7)	21 (41.2)	0.083
Axillounifemoral bypass	0	0 (0)	1 (2)	-
Popliteopopliteal bypass	0	1 (2.2)	0 (0)	-
Revision of aortobifemoral reconstruction	1 (0.8)	0 (0)	0 (0)	-
Femoral artery aneurysm plasty	2 (1.6)	1 (2.2)	0 (0)	-
Longitudinal incision (%)	122 (96.1)	43 (95.1)	49 (96.1)	0.98
Vascular reconstruction with foreign material	59 (46.5)	19 (42.2)	17 (33.3)	0.1
Hemostatic agents left in site	96 (75.6)	34 (75.6)	43 (84.3)	0.25
Type of incision dressing
Conventional	70 (55.1)	27 (60)	33 (64.7)	0.23
Incisional NPWT	57 (44.9)	18 (40)	18 (35.3)	0.23
Median procedure time (min) (IQR)	191 (143–246)	173 (148–227)	193 (158–257)	0.63
Post-operative
Intensive care	2 (1.6)	0 (0)	3 (5.9)	0.14
Median in-patient stay after index procedure (d) (IQR)	7 (5–9)	6 (5–8)	9 (6–18)	0.026

ASA = American Society of Anesthesiologists; BAC = blood albumin concentration; BGC = blood glucose concentration; GFR = glomerular filtration rate; IQR = interquartile range; NPWT = negative-pressure wound therapy; TEA = thrombendarterectomy.

Incision complication grading in relation to outcomes

The IC grade worsened after one month of follow-up in 13 patients (5.8%). The highest IC grades (2–6) were associated with the median total in-patient stay within four months post-operatively related to IC (p < 0.001). There were no differences in terms of major amputation, death, or amputation-free survival between the groups (Table 4), although IC grades 2–6 tended to be associated with a higher proportion of major amputations within one year post-operatively (p = 0.087).

Table 4.

Incision Complication Classification in Relation to Patient Outcomes

	Grade 0	Grade 1	Grade 2–6	p
No of patients	127	45	51
Median long-term follow-up (mos) (IQR)	38 (26–53)	40 (25–51)	37 (23–44)	0.41
Median in-patient stay^a (d) (IQR)	7 (5–9)	6 (5–8)	17 (12–29)	<0.001
Death by one year post-op (%)	5 (3.9)	1 (2.2)	4 (7.8)	0.35
Death within long-term follow-up^b (%)	20 (15.7)	7 (15.6)	8 (15.7)	0.99
Major amputation by one year post-op (%)	4 (3.2)	1 (2.3)	5 (9.8)	0.087
Major amputation within long-term follow-up^b (%)	7 (5.5)	4 (8.9)	5 (9.8)	0.28
Amputation-free survival within long-term follow-up^b (%)	102 (80.3)	34 (75.6)	39 (78.5)	0.51

Of index surgery and related to complications within four months post-operatively.

Until May 2019; post-op indicates post-operatively.

Inter-rater and test–retest reliability

Substantial to almost perfect agreement was seen when comparing grading scores of the three case reviewers (case reviewer 1 versus 2 κ = 0.81, 87.9% agreement; case reviewer 1 versus 3 κ = 0.71, 82.1% agreement; case reviewer 2 versus 3 κ = 0.7, 80.7% agreement). Almost perfect agreement also was seen in terms of test–retest agreement (case reviewer 1, κ = 0.91, 94.6% agreement; case reviewer 2 κ = 0.87, 85.2% agreement; case reviewer 3 κ = 0.91, 94% agreement).

Floor and ceiling effects

One hundred twenty-seven patients (57%) received grade 0 as the lowest grade observed throughout the four-month follow-up period, thereby constituting a floor effect. No ceiling effect was found, as two patients (0.9%) obtained grade 5.

Discussion

Surgical site complications have a large impact on morbidity and cost of surgical procedures. Much focus has been on SSI. From the patient's point of view, as well as from a cost and resource perspective, the distinction between SSIs and other complications is most likely less relevant than the actual clinical consequences these complications might entail. Prolonged in-patient stay, additional visits to out-patient clinics, re-admissions, and re-operations are relevant factors both for the affected patient and in terms of procedure-related resource requirements.

In the proposed classification focusing on IC only, a grading was created based on their clinical consequences. After clustering severe IC grades 2–6, it was demonstrated that patient-related factors such as previous vascular surgery [11], anemia [12], and procedure-related factors such as the extent of the surgery [13] indeed had an impact on IC grade. Although a floor effect, which generally indicates the coarseness of a classification system, was observed in the system, it could be expected that the majority of these patients would not suffer from IC.

The total number of in-patient days of patients with ICs but without an SSI diagnosis were the same as for those who had an SSI. If one considers total in-patient time as an indicator of in-patient cost [14], an obligatory overly fine distinction between SSI and other IC might seem less relevant. Furthermore, a significant financial impact of non-infection-related IC on healthcare cost can be assumed. This reasoning applies to the majority of incision-related complications. In addition, patients who, according to the ASEPSIS score, had satisfactory surgical site healing, had a surprisingly large percentage of treatment-requiring IC (17.4%). This reflects the notion that IC should be classified in much broader terms than previously practiced. However, there is a small percentage of vascular surgical patients who will develop vascular graft infections [15], which have a large impact on length of in-patient stay, amputation, and death. Yet, in the present study, peri-vascular graft infection occurred in only one patient, who had an implanted foreign-material vascular graft.

Of note was that there were all in all fewer SSIs among patients with foreign-material grafts than in those with autologous vascular reconstructions. A trend toward less IC burden was seen among patients with synthetic material implants. This might seem surprising, yet a higher SSI rate for autologous vascular reconstructions has been described in previous reports [16] and could be related to longer exposure and procedure times associated with vein harvesting, a trend that also was shown in this study. The follow-up time chosen in the present trial could, however, be too short to account for low-virulent vascular graft infections that in prosthetic material can arise years after implantation [17].

Noteworthy also was that despite lower rates of SSI, incisions treated primarily with NPWT shared a similar overall burden of IC as those with conventional dressings. The similar IC grade in the two groups may be attributed to a type 2 statistical error. It can be speculated, however, that operative technical aspects more than transcutaneous bacterial invasion of the incision post-operatively may play a greater role in the occurrence of non-SSI IC.

As shown in the present study, the length of the hospital stay seems to reflect the severity of IC better than do traditional patient outcomes such as major amputation and death and also is a comprehensible variable for resource and cost evaluation. Hence, length of stay data should be taken into account when studying IC and their impact on procedure cost [18].

One limitation of this study is its small sample of 223 patients. An external validation of the proposed classification with a larger sample including more patients with IC grades 2–6 is warranted to obtain more accurate analyses of associations between peri-operative variables and prolonged hospitalization, re-admission, re-operation, major amputation, and death. Even though this was a prospective study, distinguishing deep from peri-vascular SSI can be difficult. The use of incisional NPWT lowered the overall SSI rate in the present study. This factor might have contributed to the non-significant difference in incision morbidity between those with versus those without SSI among those with IC. It also should be acknowledged that length of IC in-hospital stay as a major contributing factor to incision morbidity might sometimes be difficult to distinguish from all-cause in-hospital stay because these patients often have multiple co-morbidities. In fact, 25% of re-admissions after lower-extremity bypass surgery have been reported not to be procedure related [19]. Nevertheless, ratings performed by three independent physicians showed that, despite different levels of clinical experience, grading according to the IC classification system was highly reproducible. A validated IC classification system could be used to increase uniformity in reporting surgical outcomes and to compare them between hospitals for improvement of quality of care, as well as to perform systematic reviews with meta-analyses and to predict outcome by using pre-operative risk factors. Because of its simplicity and reproducibility, this IC classification may be applied to other surgical disciplines.

Conclusions

The proposed classification of IC seems feasible and reproducible but needs to be validated externally. Incision complications after elective open lower-limb revascularization procedures not classified as SSI carried the same incision-related morbidity as SSI in terms of IC-related in-patient stay.

Footnotes

Author Disclosure Statement

The authors have no conflicts of interest with regard to this manuscript.

References

Turtiainen

, Hakala

. Surgical wound infections after peripheral vascular surgery. Scand J Surg, 2014; 103:226–231.

Clavien

, Sanabria

, Strasberg

. Proposed classification of complications of surgery with examples of utility in cholecystectomy. Surgery, 1992; 111:518–526.

Dindo

, Demartines

, Clavien

. Classification of surgical complications: A new proposal with evaluation in a cohort of 6336 patients and results of a survey. Ann Surg, 2004; 240:205–13.

Badia

, Casey

, Petrosillo

, et al. Impact of surgical site infection on healthcare costs and patient outcomes: A systematic review in six European countries. J Hosp Infect, 2017; 96:1–15.

Wilson

, Gibbons

, Reeves

, et al. Surgical wound infection as a performance indicator: Agreement of common definitions of wound infection in 4773 patients. BMJ, 2004; 329:720.

Hasselmann

, Björk

, Svensson-Björk

, et al. Inguinal vascular surgical wound protection by incisional negative pressure wound therapy, a randomized controlled trial—INVIPS trial. Ann Surg (In Press).

Wilson

, Treasure

, Sturridge

, et al. A scoring method (ASEPSIS) for postoperative wound infections for use in clinical trials of antibiotic prophylaxis. Lancet, 1986; 1:311–313.

National Healthcare Safety Network, Centers for Disease Control and Prevention. Surgical site infection (SSI) event 2017. Available at: http://www.cdc.gov/nhsn/pdfs/pscmanual/9pscssicurrent.pdf

Berrios-Torres

, Umscheid

, Bratzler

, et al. Centers for Disease Control and Prevention Guideline for the Prevention of Surgical Site Infection 2017. JAMA Surg, 2017; 152:784–791.

10.

McHorney

, Tarlov

. Individual-patient monitoring in clinical practice: Are available health status surveys adequate?. Qual Life Res, 1995; 4:293–307.

11.

Bodewes

TCF

, Ultee

KHJ

, Soden

, et al. Perioperative outcomes of infrainguinal bypass surgery in patients with and without prior revascularization. J Vasc Surg, 2017; 65:1354–1365.

12.

Melvin

, Smith

, Kruse

, et al. Risk factors for 30-day hospital re-admission with an infectious complication after lower-extremity vascular procedures. Surg Infect, 2017; 18:319–326.

13.

Rezk

, Astrand

, Acosta

. Antibiotic prophylaxis with trimethoprim/sulfamethoxazole instead of cloxacillin/cefotaxime increases inguinal surgical site infection rate after lower extremity revascularization. Int J Low Extrem Wounds, 2019:1534734619838749.

14.

Stenberg

, Lauer

, Gkountouras

, et al. Econometric estimation of WHO-CHOICE country-specific costs for inpatient and outpatient health service delivery. Cost Eff Resour Alloc, 2018; 16:11.

15.

Wilson

. New alternatives in management of the infected vascular prosthesis. Surg Infect, 2001; 2:171–175.

16.

O'Brien

, Pocock

, Torella

. Wound infection after reconstructive arterial surgery of the lower limbs: Risk factors and consequences. Surgeon, 2011; 9:245–248.

17.

Calligaro

, Veith

, Schwartz

, et al. Differences in early versus late extracavitary arterial graft infections. J Vasc Surg, 1995; 22:680–685.

18.

Fine

, Pratt

, Obrosky

, et al. Relation between length of hospital stay and costs of care for patients with community-acquired pneumonia. Am J Med, 2000; 109:378–385.

19.

Zhang

, Curran

, McCallum

, et al. Risk factors for readmission after lower extremity bypass in the American College of Surgeons National Surgery Quality Improvement Program. J Vasc Surg, 2014; 59:1331–1339.

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