Multicenter parallel randomized trial evaluating incisional negative pressure wound therapy for the prevention of surgical site infection after lower extremity bypass

OBJECTIVE

Incisional negative pressure wound therapy (iNPWT) applied over all incisions after lower extremity bypass in the prevention of surgical site infections (SSIs) is unclear. The primary and secondary aims of this study were to investigate if prophylactic iNPWT after the elective lower extremity bypass prevents SSI and other surgical wound complications.

METHODS

This was a multicenter, parallel, randomized controlled trial. Patients undergoing elective lower extremity bypass in 3 hospitals were randomized to either iNPWT or standard dressings. SSIs or other wound complications were assessed within the first 90 days by wound care professionals blinded to the randomized result. The validated Additional treatment, Serous discharge, Erythema, Purulent exudate, Separation of deep tissues, Isolation of bacteria, and Stay (ASEPSIS) score was used to objectively assess the wounds. ASEPSIS score ≥21 is defined as an SSI. Unilateral and bilateral groups were analyzed with the Fisher exact test and the McNemar test, respectively.

RESULTS

In the unilateral group (n = 100), the incidence of SSI in the iNPWT group was 34.9% (15/43), compared with 40.3% (23/57) in the control group, according to the ASEPSIS score (P = .678). In the bilateral group (n = 7), the SSI rate was 14.3% (1/7) in the iNPWT group compared with 14.3% (1/7) in the control group (P = 1.00). In the unilateral group, there was a higher wound dehiscence rate in the control group (43.9%) compared with the iNPWT group (23.3%) (P = .0366). No serious iNPWT-related adverse events were recorded.

CONCLUSIONS

There was no reduction of SSI rates in leg incisions with iNPWT compared with standard dressings in patients undergoing elective lower extremity bypass, whereas iNPWT reduced the incidence of wound dehiscence.

Negative Pressure Wound Therapy for the Prevention of Surgical Site Infections Using Fascia Closure After EVAR-A Randomized Trial

BACKGROUND

Surgical site infections (SSI) in the groin after vascular surgery are common. The aim of the study was to evaluate the effect of negative pressure wound therapy (NPWT) on SSI incidence when applied on closed inguinal incisions after endovascular aneurysm repair (EVAR).

METHODS

A multicenter randomized controlled trial (RCT). Between November 2013 and December 2020, 377 incisions (336 bilateral and 41 unilateral) from elective EVAR procedures with the primary intent of fascia closure were randomized and included, receiving either NPWT or a standard dressing. In bilateral incisions, each incision randomly received the opposite dressing of the other side, thereby becoming each other's control. The primary endpoint was SSI incidence at 90 days postoperatively, analyzed on an intention-to-treat basis. Uni and bilaterally operated incisions were analyzed separately, and their respective p-values combined using Fisher's method for combining P-values. Study protocol (NCT01913132).

RESULTS

The SSI incidence at 90 days postoperatively in bilateral incisions was 1.8% (n = 3/168) in the NPWT and 4.8% (n = 8/168) in the standard dressing group, and in unilateral incisions 13.3% (n = 2/15) and 11.5% (n = 3/26), respectively (combined p = 0.49). In all SSIs, bacteria were isolated from incisional wound cultures. No additional SSIs were diagnosed between 90 days and 1 year follow-up.

CONCLUSIONS

No evidence of difference in SSI incidence was seen in these low-risk inguinal incisions when comparing NPWT with standard dressings after EVAR with the primary intent of fascia closure.

CLINICAL TRIALS

NCT01913132.

Risk Factors for Abdominal Compartment Syndrome After Endovascular Repair for Ruptured Abdominal Aortic Aneurysm: A Case Control Study

OBJECTIVE

Ruptured abdominal aortic aneurysms (rAAA) are treated by endovascular aneurysm repair (rEVAR) increasingly often. Despite rEVAR being a minimally invasive method, abdominal compartment syndrome (ACS) remains a significant post-operative threat. The aim of this study was to investigate risk factors for ACS after rEVAR, including aortic morphological features.

METHODS

The Swedish vascular registry (Swedvasc) was assessed for ACS after rEVAR in the period 2008 - 2015. All patients identified were compared with controls (i.e., patients who did not develop ACS after rEVAR), matched by centre and repair date. Case records were reviewed, and radiology images analysed in a core laboratory. Comparisons were performed with respect to physiological and radiological risk factors.

RESULTS

The study population consisted of 40 patients with ACS and 68 controls. Pre-operatively, patients with ACS had a lower blood pressure (BP) than controls (median 70 mmHg vs. 97 mmHg; p < .001). Intra-operatively, they had aortic balloon occlusion more often (55.0% vs. 10.3%; p < .001) and received more transfusions than controls (median nine units of packed red blood cells [pRBC] vs. two units; p < .001). Ninety-seven per cent of those who developed ACS had a pre-operative BP < 70 mmHg, aortic balloon occlusion, or received more than five pRBC unit transfusions. Treatment outside the instructions for use did not differ between patients and controls (57.5% vs. 54.4%; p = .84), and neither did the pre-operative patency of the inferior mesenteric artery (57.1% vs. 63.9%; p = .52) nor the number of visible lumbar arteries on pre-operative imaging (2 vs. 4; p = .014). In multivariable logistic regression, the number of intra-operative transfusions were predictive of ACS (p < .001), while pre-operative hypotension (p = .32) and aortic balloon occlusion (p = .018) were not.

CONCLUSION

ACS after rEVAR is mainly associated with physiological factors and is unlikely to develop without the presence of a pre-operative BP < 70 mmHg, the need for an aortic occlusion balloon, or more than five intra-operative pRBC unit transfusions. Treatment outside the IFU or any other morphological factor were not associated with a risk of ACS.

Nationwide Study of the Treatment of Mycotic Abdominal Aortic Aneurysms Comparing Open and Endovascular Repair

Background:

No reliable comparative data exist between open repair (OR) and endovascular aneurysm repair (EVAR) for mycotic abdominal aortic aneurysms (MAAAs). This nationwide study assessed outcomes after OR and EVAR for MAAA in a population-based cohort.

Methods:

All patients treated for MAAAs in Sweden between 1994 and 2014 were identified in the Swedish vascular registry. The primary aim was to assess survival after MAAA with OR and EVAR. Secondary aims were analyses of the rate of recurrent infections and reoperations, and time trends in surgical treatment. Survival was analyzed using Kaplan-Meier and log-rank tests. A propensity score–weighted correction for risk factor differences in the 2 groups was performed, including the operation year to account for differences in treatment and outcomes over time.

Results:

We identified 132 patients (0.6% of all operated abdominal aortic aneurysms in Sweden). Mean age was 70 years (standard deviation, 9.2), and 50 presented with rupture. Survival at 3 months was 86% (95% confidence interval, 80%–92%), at 1 year 79% (72%–86%), and at 5 years 59% (50%–68%). The preferred operative technique shifted from OR to EVAR after 2001 (proportion EVAR 1994–2000 0%, 2001–2007 58%, 2008–2014 60%). Open repair was performed in 62 patients (47%): aortic resection and extra-anatomic bypass (n=7), in situ reconstruction (n=50), and patch plasty (n=3); 2 patients died intraoperatively. EVAR was performed in 70 patients (53%): standard EVAR (n=55), fenestrated/branched EVAR (n=8), and visceral deviation with stent grafting (n=7); no deaths occurred intraoperatively. Survival at 3 months was lower for OR than for EVAR (74% versus 96%, P <0.001), with a similar trend present at 1 year (73% versus 84%, P =0.054). A propensity score–weighted risk-adjusted analysis confirmed the early better survival associated with EVAR. During median follow-up of 36 and 41 months for OR and EVAR, respectively, there was no difference in long-term survival (5 years 60% versus 58%, P =0.771), infection-related complications (18% versus 24%, P =0.439), or reoperation (21% versus 24%, P =0.650).

Conclusion:

This study demonstrates a paradigm shift in treatment of MAAA in Sweden, with EVAR being the preferred treatment modality. EVAR was associated with improved short-term survival in comparison with OR, without higher associated incidence of serious infection-related complications or reoperations.

EndoVascular and Hybrid Trauma Management (EVTM) for Blunt Innominate Artery Injury with Ongoing Extravasation

Innominate artery (IA) traumatic injuries are rare but life-threatening, with high mortality and morbidity. Open surgical repair is the treatment of choice but is technically demanding. We describe a case of blunt trauma to the IA with ongoing bleeding, treated successfully by combined (hybrid) endovascular and open surgery. The case demonstrates the immediate usage of modern endovascular and surgical tools as part of endovascular and hybrid trauma management.