References
Definitions of high risk
Bariatric patient groups
Pharmacologic prophylaxis
Outcomes
Frezza et al. [47]
BMI 50 kg/m2, prior DVT or PE, prior pelvic surgery, cardiac failure
High risk + IVCF, n = 15
Preop—LV 2 mg/kg SQ × 1 or UFH 7,000 U SQ × 1
No PE or DVT
High risk + intraop UFH, n = 9
POD#1—LV 1.5–2 mg/kg SQ BID × 15 days then Coumadin ≥3 months
Gargiulo et al. [48]
BMI > 55 kg/m2, prior DVT/PE, pulm HTN
1. High risk + IVCF n = 17
Preop—UFH 50 U/kg SQ × 1
Decreased PE (28 % vs. 0 %) and fatal PE (11 % vs. 0 %) favoring IVCF
2. High risk, no IVCF, n = 18
Postop—UFH 50 U/kg SQ q12 h until ambulatory
Halmi et al. [49]
Prior DVT/PE, hypercoag state, severe OSA, pulm HTN, immobility, BMI > 65 kg/m2
High risk, n = 27
Preop—UFH 5,000 U × 1 or LV 40 mg SQ × 1
No DVT or PE
Postop—UFH 5,000 U SQ q 8 h or LV 40 mg SQ q12 h × 3 weeks
Kardys et al. [24]
BMI > 50 kg/m2, venous insuff, hypercoag state, immobility, or prior VTE
High risk, n = 31
Preop—UFH 5,000 U SQ × 1
DVT 1/31, PE 2/31
POD#1—LV 40 mg SQ BID
If BMI > 60 LV × 2 weeks
Keeling et al. [42]
Prior PE/DVT, venous stasis
High risk, n = 14
Periop—LV 40 mg SQ BID
No PE
If BMI > 60—LV 30 mg SQ BID
Obeid et al. [43]
Immobility, prior DVT/PE, venous disease, BMI > 60 kg/m2, prior IVCF
1. High risk + IVCF n = 248
Postop—LV dose not specified
No difference in PE (0.81 % vs. 0.59 %), DVT (1.21 % vs. 0.65 %), or death (0.81 % vs. 0.22 %)
IVCF group—LV + Coumadin 1 mg/d
2. Low risk, no IVCF n = 1,851
Overby et al. [50]
Thrombophilia, immobility, h/o venous stasis, pulm HTN, severe OSA, BMI > 60 kg/m2, Prior DVT/PE
1. High risk + IVCF, n = 160
Preop—UFH 5,000–75,000 U SQ q8 h
No difference in PE (3 % vs. 2 %) or DVT (0.6 % vs. 3 %)
2. Low risk, no IVCF, n = 170
Postop—UFH 5,000–7,500 U Q q8 h
Piano et al. [51]
BMI > 55 kg/m2, hypercoagulable state, immobility, venous stasis, prior DVT/PE
High risk n = 60
Preop—none
PE 1/60 (received no pharmacologic prophylaxis)
Intraop—IV UFH max 750 U/h
Postop—LV BID at discharge (goal LMW level 0.3–0.5)
Schuster et al. [44]
Prior DVT/PE, severe venous stasis, sleep apnea, wt > 400 lbs
High risk, n = 24
Preop—SQ UFH
DVT 5/24, PE 1/24 (after IVCF retrieval)
Trigilio-Black et al. [45]
Prior DVT/PE, venous stasis, pulmonary compromise, immobility
High risk n = 41
Preop—LV 30 mg SQ × 1
DVT 1/41, no PE
Postop—LV 30 mg SQ BID
Vaziri et al. [52]
Prior VTE
High risk n = 30
Preop—UFH 5,000 U SQ × 1
DVT 6/30, no PE
Postop—UFH 5,000 U SQ q8 h
Several studies have shown an increased risk of perioperative morbidity in bariatric patients who had a preoperative IVC filter placed, raising the concern for these devices causing more harm than good. Birkmeyer et al. performed a retrospective review of the Michigan Bariatric Surgery Collaborative database between 2006 and 2008 [53]. Out of 6,376 patients undergoing gastric bypass surgery, 542 patients (8.5 %) had a preoperative IVC filter placed. They used propensity scores in an attempt to control for selection bias related to IVC filter placement in higher-risk patients. In their review, patients receiving IVC filters were in fact higher risk with significantly higher rates of multiple comorbidities to include: history of VTE, age > 50 years, BMI > 50 kg/m2, male gender, mobility problems, lung disease, cardiovascular disease, diabetes, and sleep apnea. Additionally these patients were more likely to undergo open gastric bypass and have operative times >3 h. Without risk adjustment, the IVC filter group experienced significantly higher complication rates including postoperative VTE events 2.03 % vs. 0.53 %, serious complications 7.56 % vs. 3.62 % (not specifically defined in the study), and permanent disability/death 1.85 % vs. 0.51 %. After applying risk-adjusted propensity scores, the statistical significance of these adverse outcomes was no longer present, but there was a trend towards worse outcomes in the IVC filter group. There were two reported complications directly related to the IVC filter to include a fatal IVC thrombosis and an IVC filter migration to the heart. They concluded that prophylactic IVC filters in gastric bypass patients do not decrease the risk of PEs and may lead to additional complications.
Despite the rare complications directly related to the IVC filter, it is difficult to quantify the potential benefit in this high-risk group of patients who were perhaps protected from major PEs and possible subsequent mortality.
Another concern with using IVC filters is the potential for delayed mechanical and/or pharmacologic prophylaxis due to the perception of the patient being protected from a PE. Caution must be taken to avoid this misconception as an IVC filter alone is not sufficient to safeguard against VTE events including a significant and potentially fatal PE. The American Society of Hematology consensus statements concluded that there is insufficient evidence to support the use of IVC filters at the time of bariatric surgery [54].
Systematic Reviews
There have been two key review articles evaluating the published literature of VTE prophylaxis in the bariatric patient. Rocha et al. performed a systemic review of the risk of VTE complications and efficacy of prophylaxis in both obese medical and bariatric surgery patients [25]. Their review found eight studies, six-level 2B and two-level 2C, published between 2001 and 2005 looking at VTE prophylaxis in the bariatric patient. They were unable to find any level 1A recommendations for prophylaxis for either the medical or surgical patients. A lack of high-quality prospective studies prevented identifying the most effective and/or safest prophylactic regimen. However, they concluded that the use of some form of chemoprophylaxis is needed. They also determined that obesity was an independent risk factor for VTE events in the medical patients.
Agarwal et al. updated the systemic review by Rocha, looking at the literature between 2006 and 2009 (Table 2) [55]. The goal was to examine the best, most current evidence for VTE prophylaxis in bariatric surgery patients. They reviewed two evidence-based guidelines which will be discussed later and discovered 30 primary studies, including the 8 cited by Rocha. Only one of these was a randomized controlled trial (RCT), and 22 studies did not have a control cohort. There was a wide range of prophylactic methods used which included: mechanical prophylaxis alone (1 study) [56], LMWH alone (3 studies) [28, 31, 57], LMWH and mechanical prophylaxis (4 studies) [22, 32, 58, 59], subcutaneous UFH and mechanical prophylaxis (2 studies) [35, 60], IV UFH and mechanical prophylaxis (2 studies) [61–63], IVC filters combined with mechanical and/or pharmacologic prophylaxis (11 studies) [23, 24, 42–45, 48, 49, 51, 64, 65], and variable methods (5 studies). They discovered a lack of RCTs and case-controlled studies in the published literature. There were several important findings from their systemic review. In most studies both mechanical and pharmacologic prophylaxis were used in both the preoperative and postoperative settings, including the encouragement of early ambulation. Patients who were considered to be higher risk (i.e., history of hypercoagulable disorder, prior DVT or PE, immobile, pulmonary hypertension, obstructive sleep apnea, venous stasis disease, BMI > 55 kg/m2) were commonly treated with the addition of IVC filters. The studies also identified that VTE events frequently occurred after hospital discharge. Conclusions drawn from their review that can provide treatment guidelines are:
Table 2.
Systematic review of prophylactic regimens to prevent venous thromboembolism after bariatric surgery
Category | Year of publication | Investigator | Study design | Patients (n) | Procedure | Intervention | DVT, % | PE, % | Bleeding, % | Mortality, % |
|---|---|---|---|---|---|---|---|---|---|---|
LMWH | 2001 | Kalifarentzos et al. [31] | RCT | 60 | Roux-en-Y (unspecified) | Nadroparin 5,700 IU/d | 0 | NR | 0 | NR |
LMWH/mechanical prophylaxis | 2002 | Scholten et al. [22] | Prospective, controlled | 481 | Various | Enoxaparin 30 mg BID; mechanical prophylaxis/enoxaparin 40 mg BID; mechanical prophylaxis | 5.4/0.5 combined DVT/PE | 1.1/0.3 | NR | |
Intravenous heparin/mechanical prophylaxis | 2003 | Shepherd et al. [61] | Prospective, uncontrolled | 700 | Laparoscopic Roux-en-Y | IV heparin continuous, target anti-factor Xa . 11–.25 U/mL; mechanical prophylaxis | 0 | 0.4 | 2.3 | 0 |
Mechanical prophylaxis | 2004 | Gonzalez et al. [56] | Prospective, uncontrolled | 380 | Laparoscopic Roux-en-Y | Mechanical prophylaxis | 0.26 | 0 | NR | NR |
Subcutaneous heparin/mechanical prophylaxis | 2004 | Miller et al. [35] | Retrospective, uncontrolled | 250 | Laparoscopic Roux-en-Y | SQ heparin TID 5,000 U if BMI <50 kg/m2, 7,500 U if BMI >50 kg/m2; mechanical prophylaxis | 0.4 | 1.2 | 2.4 | NR |
Intravenous heparin/mechanical prophylaxis | 2004 | Shepherd et al. [62] | Prospective, uncontrolled | 19 | Laparoscopic Roux-en-Y | IV heparin continuous, target anti-factor Xa 0.15–0.20 U/mL; mechanical prophylaxis | 0 | 0 | 0 | NR |
Subcutaneous heparin/mechanical prophylaxis | 2005 | Cotter et al. [60] | Retrospective, uncontrolled | 107 | Open or laparoscopic Roux-en-Y | SQ heparin 5,000 U BID; mechanical prophylaxis | 0.9 | NR | NR | NR |
LMWH | 2005 | Hamad et al. [28] | Retrospective, uncontrolled | 668 | Various | Enoxaparin (various doses) | 0.1 | 0.9 | 1 | 0.3 |
IVC filter/pharmacologic prophylaxis/mechanical prophylaxis | 2005 | Keeling et al. [42] | Retrospective, uncontrolled | 14 | Unspecified gastric bypass | IVC filter; SQ heparin (dose NR); enoxaparin if BMI 40–60 kg/m2, 40 U/d; if BMI >60 kg/m2, 30 U BID; mechanical prophylaxis | 0 | 0 | NR | NR |
IVC filter/pharmacologic prophylaxis/mechanical prophylaxis | 2005 | Prystowsky et al. [64] | Prospective, uncontrolled | 106 | Unspecified Roux-en-Y | IVC filter; SQ heparin 5,000 U BID; mechanical prophylaxis | 3.8 | 0 | 1.9 | 0 |
Intravenous heparin/mechanical prophylaxis | 2005 | Quebbemann et al. [21] | Prospective, uncontrolled | 822 | Various | IV heparin, continuous, 400 U/h; mechanical prophylaxis | 0 | 0.1 | 1.3 | NR |
LMWH/mechanical prophylaxis | 2006 | Abou-Nukta et al. [58] | Retrospective, uncontrolled | 1,225 | Open Roux-en-Y | Enoxaparin 40 mg BID; mechanical prophylaxis | NR | 0.9 | NR | NR |
IVC filter/pharmacologic prophylaxis/mechanical prophylaxis | 2006 | Gargiulo et al. [48] | Prospective, controlled | 571 | Open Roux-en-Y | IVC filter indicated for h/o DVT, PE, or pulmonary HTN; SQ heparin 50 U/kg BID; mechanical prophylaxis/IVC filter indicated for h/o DVT, PE, or pulmonary HTN or BMI >55 kg/m2; SQ heparin 50 U/kg BID; mechanical prophylaxis/IVC filter offered to patients with BMI >55 kg/m2; SQ heparin 50 U/kg BID; mechanical prophylaxis | NR | 2.1/0/NR | NR | 2.1/0.6/NR |
IVC filter/pharmacologic prophylaxis/mechanical prophylaxis | 2006 | Gonzalez et al. [65] | Prospective, uncontrolled | 660 | Laparoscopic Roux-en-Y | IVC filter; SQ heparin (dose NR); enoxaparin 40 mg/d for BMI < 50 kg/m2 and 30 mg BID for BMI ≥ 50 kg/m2; mechanical prophylaxis; extended prophylaxis for high-risk factors | 1.4 | 0.9 | NR | 0.5 |
Intravenous heparin/mechanical prophylaxis | 2007 | Cossu et al. [63] | Pre–post comparison study | 151 | Biliopancreatic diversion or vertical banded gastroplasty | IV heparin 2,500–5,000 U, single dose; mechanical prophylaxis/SQ heparin aPTT adjusted; mechanical prophylaxis | NR | 3.1/1.2 | 0/0 | 4.6/0 |
LMWH/mechanical prophylaxis | 2007 | Forestieri et al. [59] | Prospective, uncontrolled | 10 | Biliointestinal bypass | Parnaparin 3,200–6,400 IU/d; mechanical prophylaxis | 0 | 10 | 0 | NR |
IVC filter/pharmacologic prophylaxis/mechanical prophylaxis | 2007 | Halmi et al. [49]
Related posts: Laparoscopic Malabsorption Procedures: Management of Nutritional Complications After Biliopancreatic Diversion
Long-Term Mortality After Bariatric Surgery
 Laparoscopic Sleeve Gastrectomy: Outcomes
 Sleeve Gastrectomy: Technique, Pearls, and Pitfalls
 Pathophysiology of Obesity Comorbidity: The Effects of Chronically Increased Intra-abdominal Pressure
 Laparoscopic Malabsorptive Procedures: Technique of Duodenal Switch
 Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
Get Clinical Tree app for offline access
|