Optimal Timing of Perioperative Chemical Thromboprophylaxis in Elective Major Abdominal Surgery: A Systematic Review and Meta-analysis.

OBJECTIVE: To investigate the effect of the timing of chemoprophylaxis on venous thromboembolisms (VTEs) and bleeding rates in patients undergoing major abdominal surgery. BACKGROUND: Postoperative bleeding and VTE incur significant morbidity, mortality, and health care costs. Chemoprophylaxis is used routinely to prevent VTEs but increases bleeding risk. The perioperative timing of chemoprophylaxis initiation may influence both VTE and bleeding risks. The optimal window for commencing chemoprophylaxis in the perioperative period is unclear. METHODS: MEDLINE, EMBASE, Cochrane Library, and Web of Science databases were searched using PRISMA guidelines. Randomized trials and cohort studies published between January 1, 2000 to May 10, 2022, which reported on chemoprophylaxis timing as well as the incidence of VTE and bleeding after elective abdominal surgery were meta-analyzed. RESULTS: From 6175 studies, 14 (24,922 patients) were meta-analyzed. Bariatric (4 studies), antireflux (1 study), hepato-pancreatic-biliary (5 studies), colorectal (1 study), ventral hernia (1 study), and major intra-abdominal surgeries (2 studies) were included. Chemoprophylaxis was initiated before skin closure in 10,403 patients, and postoperatively in 14,519 patients. Both symptomatic [risk ratios (RR), 0.81; 95% CI, 0.45-1.43; P =0.460] and overall (RR, 0.74; 95% CI, 0.45-1.24; P =0.250) VTE rates were comparable between study groups. Compared with postoperative chemoprophylaxis, early usage increased the risk of all bleeding (RR, 1.56; 95% CI, 1.13-2.15; P =0.007), major bleeding (RR, 1.63; 95% CI, 1.16-2.28; P =0.005), blood transfusion (RR, 1.48; 95% CI, 1.24-1.76; P <0.001), and reintervention (RR, 1.94; 95% CI, 1.19-3.18; P =0.008). CONCLUSIONS: Our findings advocate for initiating chemoprophylaxis postoperatively in elective abdominal surgery to minimize bleeding risk without compromising VTE protection.

Optimal Timing of Perioperative Chemoprophylaxis in Patients With High Thromboembolic Risk Undergoing Major Abdominal Surgery: A Multicenter Cohort Study.

OBJECTIVE: To determine whether early (before skin closure) versus postoperative chemoprophylaxis affects the incidence of venous thromboembolism (VTE) and bleeding following major abdominal surgery, in a high thromboembolic risk population. BACKGROUND: Major abdominal surgery incurs both VTE and bleeding risks. Patients with high preoperative VTE risk derive the most benefit from chemoprophylaxis, but carry an increased risk of bleeding. The optimal window for chemoprophylaxis in the perioperative period, whereby both VTE and bleeding risks are minimized, is unknown. METHODS: Analysis of pooled data from 5 multicenter studies including only high thromboembolic risk (Caprini score >4) patients. Clinical VTE was defined as radiographically proven symptomatic disease <30 days postsurgery. Major bleeding was defined as the need for blood transfusion, reintervention, or >20 g/L fall in hemoglobin. RESULTS: From 5501 cases, chemoprophylaxis was initiated early in 1752 (31.8%) patients and postoperatively in 3749 (68.2%) patients. Baseline characteristics were similar between study groups. The incidence of clinical VTE was not associated with chemoprophylaxis timing [early 0.7% vs. postop 0.7%, odds ratio (OR): 1.11, 95% confidence interval (CI): 0.60-2.15, P =0.730]. Contrastingly, compared with postoperative chemoprophylaxis, early usage increased the risk of all bleeding (5.1% vs. 2.6%, OR: 2.04, 95% CI: 1.52-2.73, P <0.001) major bleeding (3.6% vs. 1.8%, OR: 1.99, 95% CI: 1.40-2.81, P <0.001), and reintervention (2.0% vs. 1.0%, OR: 2.10, 95% CI: 1.32-3.35, P =0.003). Early chemoprophylaxis independently predicted postoperative bleeding (OR: 1.71, 95% CI: 1.25-2.34, P <0.001), but not VTE. CONCLUSIONS: In high VTE risk patients undergoing major abdominal surgery, chemoprophylaxis commenced postoperatively reduces bleeding risk without affecting clinical VTE risk.

The surgical management of metastatic pancreatic acinar cell carcinoma and associated pancreatic panniculitis-A case report and literature review.

INTRODUCTION: Pancreatic panniculitis is a rare manifestation of benign and malignant pancreatic disease. The presentation of pancreatic panniculitis is non-specific and thus diagnosis is often delayed. When associated with malignancy, pancreatic panniculitis confers a poor prognosis. This case demonstrates the successful surgical management of this paraneoplastic phenomenon following resection of the underlying pancreatic acinar cell carcinoma and associated liver metastasis. PRESENTATION OF CASE: A 71-year-old female with debilitating subcutaneous lower limb lesions had a delayed diagnosis of pancreatic panniculitis. A formal diagnosis of pancreatic acinar cell carcinoma with liver metastasis was established and the disease was determined to be resectable. Pre-operatively, serum lipase measured 10,825 U/L. The patient proceeded to an open left hemihepatectomy and radical distal pancreatectomy with complete resection of malignant disease. Six days post-operatively the serum lipase levels normalised, and the panniculitis began to settle. The patient proceeded to adjuvant FOLFORINOX chemotherapy. Twenty months post-surgery, the patient remains disease-free and without any evidence of panniculitis. DISCUSSION: Due to the rarity of pancreatic acinar cell carcinoma, guidelines based on prospective data do not exist. Most management is based on retrospective analyses. A survival benefit may be achieved with more aggressive surgical management compared to other pancreatic cancer types. Pancreatic acinar cell carcinoma may show a slower rate of disease progression, an increased likelihood of resectability of disease at presentation and is more likely to undergo potentially curative resection. CONCLUSION: Aggressive surgical management of resectable metastatic pancreatic acinar cell carcinoma can treat pancreatic panniculitis and provide sustained disease-free survival from pancreatic cancer.