早期联合应用抗凝药物预防脾切断流术后门静脉血栓的形成

Incidence of Splanchnic Vein Thrombosis After Abdominal Surgery: A Systematic Review and Meta-analysis

BACKGROUND

Abdominal surgery may increase the risk of splanchnic vein thrombosis (SVT). We determined the incidence of SVT after abdominal surgery and identified groups at highest risk.

MATERIALS AND METHODS

MEDLINE and Embase were searched for clinical studies evaluating the incidence of postoperative SVT after abdominopelvic surgery. Study selection, data abstraction, and risk of bias assessment were carried out independently by two reviewers. Clinical heterogeneity was explored by subgroup analyses (i.e., type of intra-abdominal procedure and organ group).

RESULTS

Of 5549 abstracts screened, 48 were analyzed. Pooled incidence of SVT (n = 50,267) was 2.68% [95% confidence interval (CI), 2.24 to 3.11] (1347 events), I² = 96%. Pooled incidence of SVT in high-risk procedures were splenectomy with devascularization (24%), hepatectomy in patients with cirrhosis (9%), and pancreatectomy with venous resection (5%). Pooled incidence of symptomatic and asymptomatic SVT was 1.02% (95% CI: 0.97% to 1.07%) and 0.98% (95% CI 0.88% to 1.07%), respectively. Most common causes of SVT-related mortality were irreversible thrombosis, bowel ischemia, liver failure, and gastrointestinal bleed. Most studies included were at a high risk of bias due to lack of prospective data collection and lack of SVT screening for all participants.

CONCLUSIONS

Incidence of SVT after abdominal surgery is low but remains a relevant complication. Patients undergoing procedures involving surgical manipulation of the venous system and splenectomy are at the highest risk. Given the life-threatening risks associated with SVT, there is a need for larger prospective studies on the incidence and impact of SVT after abdominal surgery.

Effective Prevention for Portal Venous System Thrombosis After Splenectomy: A Meta-Analysis

PURPOSE

Portal venous system thrombosis (PVST) is a common and potentially life-threatening complication of splenectomy for portal hypertension due to cirrhosis.

METHODS

A meta-analysis was conducted to study the necessity of pharmacologic prophylaxis of PVST after splenectomy and how to select the feasible treatment method. Articles were searched through the PubMed, EMBASE, Cochrane Library databases, and CNKI.

RESULTS

Overall, 404 articles were initially identified, and 11 of them were eligible. Among these selected articles, 7 articles were associated with the necessity of anticoagulation for prevention of PVST, while 5 were about the drug selection. We first demonstrated that the incidence of PVST after splenectomy was significantly lower in patients who received the preventive measures than in those who did not (odds ratio [OR]: 0.22, 95% confidence interval [CI]: 0.13-0.39, P < .00001). Then, we compared the new-style treatment with the conventional treatment and found that patients with new therapy method had lower incidence of PVST than those who received conventional treatment (OR: 0.37, 95% CI: 0.27-0.51, P < .00001). Also, some studies (n = 4) reported that early and combination use of anticoagulation drugs can lead to better outcome for patients with splenectomy and devascularization.

CONCLUSION

Preventative use of anticoagulant drugs might decrease the incidence of PVST after splenectomy in patients with portal hypertension, new anticoagulant drugs such as low-molecular-weight heparin should be used, and early or combination use of anticoagulation drugs might lead to lower PVST incidence for patients.

Postoperative Anticoagulants in Preventing Portal Vein Thrombosis in Patients Undergoing Splenectomy Because of Liver Cirrhosis: A Meta-Analysis

Portal vein thrombosis (PVT) frequently occurs in patients undergoing splenectomy because of liver cirrhosis. Whether the use of postoperative anticoagulants can decrease the incidence of PVT in these subjects is inconclusive. Moreover, the safety of the use of postoperative anticoagulants in the aforementioned patients is a concern. This meta-analysis aims to explore the effectiveness and safety of the preventive anticoagulants to prevent PVT in patients undergoing splenectomy because of liver cirrhosis. Four English language databases (i.e., PubMed, Embase, Cochrane Library, and Web of Science) and four Chinese language databases (i.e., Wanfang, CNKI, Cqvip, and CBM) were searched for randomized controlled trials, cohort studies, and case-control studies on the use of preventive anticoagulants to prevent PVT in patients undergoing splenectomy because of liver cirrhosis from their inception to September 15, 2015. The primary outcome was postoperative PVT incidence. The secondary outcomes included postoperative complications and adverse reaction. Study-specific odds ratios were combined to calculate pooled value through a fixed effects model. A total of 17 original studies were included, involving 1,497 patients. This meta-analysis showed that the preventive anticoagulant group had a lower incidence of PVT than the no anticoagulant group (odds ratio, 0.31; 95% confidence interval, 0.23–0.40; P < 0.05). According to the description of limited studies, the upper gastrointestinal hemorrhage mainly occurred in the no anticoagulant group. Meanwhile, the adverse reaction was trivial in the group using anticoagulants, which could easily be released with no special management. Postoperative anticoagulants can effectively decrease PVT incidence in subjects undergoing splenectomy because of liver cirrhosis. These published studies are more prone to show that no serious negative influence of anticoagulants exists in the aspect of safety. However, further studies are still needed.

Reduced Survival in Bariatric Surgery Candidates Delayed or Denied by Lack of Insurance Approval

Bariatric surgery reduces mortality for Americans who meet candidacy criteria and have insurance coverage. Unfortunately, some medically suitable candidates are denied or delayed during insurance approval processes. The long-term impact of such care delays on survival is unknown. Using a prospectively maintained bariatric intake database, we identified consecutive applicants who were evaluated and medically cleared by our multidisciplinary care team and for whom insurance approval was requested. We compared survival in those who were initially approved by their insurance carriers (controls) and those who were initially denied coverage (subjects). Mortality was determined using the Social Security Death Index. Kaplan–Meier survival curves were plotted and the log-rank test for significance was applied. From August 2003 to December 2008, 463 patients (391 females, mean age 45 ± 10 years, mean body mass index 52.5 ± 9.4 kg/m2) were medically cleared for a bariatric procedure. Of these, 363 were approved by insurance on initial request, whereas 100 were denied. Given the study's intention to measure the aggregate impact of delays and denials, nine patients who later came to operation after appeal or coverage change were maintained in the subject cohort. During 0- to 113-month follow-up, six subjects (6%) died compared with seven controls (1.9%), corresponding to a statistically significant survival benefit for patients initially approved for bariatric surgery without delay or denial ( P < 0.001). In conclusion, access to bariatric surgical care was impeded by insurance certification processes in 22 per cent of medically acceptable candidates. Processes that delay or restrict efficient access to bariatric surgery are associated with a 3-fold mortality increase.