Key messages
Using sealants for bleeding anastomoses in vascular surgery may result in faster time to no bleeding and fewer failures in stopping the bleeding, but did not provide better results for other outcomes such as the amount of bleeding during surgery, the length of the operation, death, bleeding after surgery, or having to return to the operating room after surgery because of bleeding. The certainty of our findings was low or very low, because most of the studies had important limitations in the way they were conducted.
What are anastomoses and sealants?
In vascular surgery, arteries and veins are often connected together using stitches. Such connections are known as anastomoses. When these connections are created, bleeding can occur from the needle holes of the sutures. Surgeons can use a variety of techniques to stop this bleeding (known as achieving hemostasis). The techniques used include applying pressure and other materials such as medicated foams that can be absorbed into the site. One type of material that is often used are sealants, which help recreate key steps of the body's natural clotting mechanism.
What did we want to find out?
We wanted to compare sealants with other types of techniques or materials used to stop bleeding in vascular surgery.
What did we do?
We included 24 clinical trials that randomized 2376 participants and combined their results together using a standardized process to determine how effective sealants were in stopping bleeding in vascular surgery. The trials included anastomoses in vascular surgery and were primarily carried out in the United States and Europe, with a few taking place in the United Kingdom, Japan, and other countries.
What did we find?
Using sealants may result in faster time to stopping bleeding in the anastomoses, and sealants were potentially less likely to fail at stopping bleeding in comparison to other techniques or materials. However, using sealants did not clearly result in less bleeding, less operating time, less bleeding following surgery during recovery for 30 days, or lower likelihood of having to go back to the operating room for bleeding complications during recovery for 30 days. None of the studies reported any deaths because of sealant use, and none of the studies investigated whether using sealants provided a better quality of life for patients.
What are the limitations of the evidence?
Most studies did not specify how they randomized participants, or how they kept the randomization process hidden. This is important because randomizing participants properly, and keeping the process hidden, can make us more confident that the study is determining only the difference in the techniques and not something else. No studies prevented the surgeons or staff from knowing which technique or material was being used to stop bleeding. This is important because awareness of which technique or material was being used can influence the surgeons' or staff's judgment of how effective they are. Thirteen of the studies had high rates of participants not completing their follow-up time period, or not completing the study for other reasons. All the studies had risk factors for introducing other sources of bias into the study.
As a result, the certainty of evidence was low or very low for all the outcomes.
How up to date is this evidence?
We searched for studies up to March 2023.
Based on meta-analysis of 24 trials with 2376 participants, our review demonstrated that sealant use for achieving anastomotic hemostasis in vascular surgery patients may result in reduced time to hemostasis, and may reduce rates of hemostatic intervention failure, although the evidence is very uncertain, when compared to standard controls. Our analysis showed there may be no differences in intraoperative blood loss, operating time, postoperative bleeding up to 30 days, and unplanned return to the operating room for bleeding complications up to 30 days. Deaths and quality of life could not be analyzed. Limitations include the risk of bias in all studies.
Our review has demonstrated that using sealants may reduce the time required to achieve hemostasis and the rate of hemostatic failure. However, a significant risk of bias was identified in the included studies, and future trials are needed to provide unbiased data and address other considerations such as cost-effectiveness and adverse events with sealant use.
During vascular interventions, connections that link arteries, veins, or synthetic grafts, which are known as an ‘anastomosis', may be necessary. Vascular anastomoses can bleed from the needle holes that result from the creation of the anastomoses. Various surgical options are available for achieving hemostasis, or the stopping of bleeding, including the application of sealants directly onto the bleeding vessels or tissues. Sealants are designed for use in vascular surgery as adjuncts when conventional interventions are ineffective and are applied directly by the surgeon to seal bleeding anastomoses. Despite the availability of several different types of sealants, the evidence for the clinical efficacy of these hemostatic adjuncts has not been definitively established in vascular surgery patients.
To evaluate the benefits and harms of sealants as adjuncts for achieving anastomotic site hemostasis in patients undergoing vascular surgery.
The Cochrane Vascular Information Specialist conducted systematic searches of the following databases: the Cochrane Vascular Specialised Register via the Cochrane Register of Studies; the Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE via Ovid; Embase via Ovid ; and CINAHL via EBSCO. We also searched ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform for clinical trials. Reference lists of included trials and relevant reviews were also searched. The latest search date was 6 March 2023.
We included randomized controlled trials that compared fibrin or synthetic sealant use with alternative interventions (e.g. manual compression, reversal of anticoagulation) for achieving anastomotic-site hemostasis in vascular surgery procedures. We included participants who underwent the creation of an anastomosis during vascular surgery. We excluded non-vascular surgery patients.
We have used standard Cochrane methods. Our primary outcomes were time to hemostasis, failure of hemostatic intervention, and intraoperative blood loss. Our secondary outcomes were operating time, death from bleeding complications up to 30 days, postoperative bleeding up to 30 days, unplanned return to the operating room for bleeding complications management up to 30 days, quality of life, and adverse events. We used GRADE to assess the certainty of evidence for each outcome.
We found 24 randomized controlled trials that included a total of 2376 participants who met the inclusion criteria. All trials compared sealant use with standard care controls, including oxidized cellulose, gelatin sponge, and manual compression. All trials were at high risk of performance bias, detection bias, and other sources of bias. We downgraded the certainty of evidence for risk of bias concerns, inconsistency, imprecision and possible publication bias.
Combining data on time to hemostasis showed that sealant use may reduce the mean time to hemostasis compared to control (mean difference (MD) -230.09 seconds, 95% confidence interval (CI) -329.24 to -130.94; P < 0.00001; 7 studies, 498 participants; low-certainty evidence). Combining data on failure of hemostatic intervention showed that sealant use may reduce the rate of failure compared to control, but the evidence is very uncertain (risk ratio (RR) 0.46, 95% CI 0.35 to 0.61; P < 0.00001; 17 studies, 2120 participants; very low-certainty evidence). We did not detect any clear differences between the sealant and control groups for intraoperative blood loss (MD -32.69 mL, 95% CI -96.21 to 30.83; P = 0.31; 3 studies, 266 participants; low-certainty evidence); operating time (MD -18.72 minutes, 95% CI -40.18 to 2.73; P = 0.09; 4 studies, 436 participants; low-certainty evidence); postoperative bleeding (RR 0.78, 95% CI 0.59 to 1.04; P = 0.09; 9 studies, 1216 participants; low-certainty evidence), or unplanned return to the operating room (RR 0.27, 95% CI 0.04 to 1.69; P = 0.16; 8 studies, 721 participants; low-certainty evidence). No studies reported death from bleeding or quality of life outcomes.