- Email: [email protected]
Time Is Now: Venous Thromboembolism Prophylaxis in Blunt Splenic Injury
298
Abstracts
Journal of Vascular Surgery: Venous and Lymphatic Disorders March 2017
the filter is grasped with a snare, and the filter is pulled into the sheath for about 1/4 or 1/3 of its length. Manual negative suction using a 20-mL syringe is applied to the sheath side port as the filter is completely pulled into sheath. The entire sheath, filter, and snare is removed from the femoral vein. Experience has demonstrated that this can be safely accomplished in those with smaller than 3-cm-diameter clots. For those with larger clot burden, CDT (1-7 days) attempted to decrease the thrombus to <2 x 3 cm, at which point aspiration thrombectomy or standard removal could be attempted. If the clot burden could not be reduced, retrieval was abandoned. Two hundred thirty-six cases (30.9%) demonstrated thrombus in the filter in preretrieval venography obtained 12 to 39 days after insertion (average, 16.9 days). A simple snare and sheath technique allowed successful removal in 120 of 121 cases with small clot present. One failure was due to the filter hook being imbedded in the IVC wall. Massive thrombus was present in 97 cases and complete occlusion was present in 18. At the time of retrieval, 97.9% were asymptomatic. Seventy-eight patients with massive filter thrombus received CDT with successful lysis in 55 patients to a small clot burden and 54 were successfully removed with the standard retrieval method. Twenty-three patients had no significant clot regression, 15 were left as a permanent filter, and 8 were retrieved with aspiration thrombectomy. In the other 19 patients, aspiration thrombectomy was successful without the need for additional thrombolysis. All 18 patients with complete occlusion underwent CDT; six filters were ultimately left in place, with the others successfully lysed sufficiently for standard (n ¼ 7) or aspiration thrombectomy (n ¼ 5) removal. No symptomatic PE or DVT progression was noted up to 2 weeks following removal. No major bleeding occurred during CDT, but there were two cases of gross hematuria. Comments: This is likely the largest reported series of filter retrieval in patients with significant thrombus present at time of removal, especially those with massive clot or complete IVC occlusion. Introduction of the aspiration thrombectomy method to aid in retrieval for those with moderate clot burden (<2 x 3 cm) is also interesting and potentially a useful addition to filter retrieval. The lack of PE symptoms following the aspiration technique is reassuring, but the lack of postintervention imaging does not allow an estimate of residual local disease nor a measure of nonclinical PE. This series of patient did require PE prevention and so filter placement was appropriate. Removal after adequate anticoagulation to prevent the known complications associated with long-term filter placement, even on anticoagulation, is known and support retrieval as attempted by these investigators. The PREPIC study is the only randomized controlled study to look at the combined use of filter and anticoagulation to date and note some benefit early with combined therapy but also the long term negative effect of filters. (Decousus H et al. A clinical trial of vena caval filters in the prevention of pulmonary embolism in patients with proximal deep-vein thrombosis. Prevention du Risque d’ Embolie Pulmonaire par Interruption Cave Study Group. N Engl J Med 1998;338:409-15).
Is a Venocavagram Necessary after Inferior Vena Cava Filter Retrieval? Mintz JD, Stavropoulos, 27:1857-64.
Trerotola SO. J Vasc Interv Radiol 2016;
Conclusion: The lack of venographic abnormalities requiring treatment after routine inferior vena cava (IVC) filter retrieval suggests that postintervention venocavography can be eliminated. After difficult retrievals, extravasation requiring treatment may justify continuing its limited use. Summary: This single-institution, 10-year retrospective cohort study involved all 245 patients with successful IVC filter retrieval and having a postretrieval venacavogram. Excluding 22 patients for missing records (four for extensive baseline thrombosis and two due to retrieval within a day) left 228 retrievals (120 routine and 108 complex) in 224 patients (four patients required two filter retrievals). The majority of filters were the Recovery series, Celect, or Gunther Tulip designs. A prior retrieval was attempted in one routine and 73 complex retrieval cases. A complex retrieval was defined as one requiring forceps or other adjuncts beyond a snare or dedicated retrieval device. The only major abnormality after retrieval was extravasation (three cases and only in the complex group). The treatment in each was balloon tamponade to approximate IVC diameter for 5-minute inflations repeated until resolution and then observation. There were more minor abnormalities noted after complex retrievals (n ¼ 85) than routine retrievals (n ¼ 62; P < .001). Minor abnormalities (consisting of stenosis, the most significant being the 51%-75%
category) were noted in 2% vs 6% routine vs complex cases, and spasm and filling defects (not clearly defined but noted as present in 10% routine vs 38% complex cases; P ¼ .001) had no effect on patient management. The frequency of abnormalities did not vary with filter type nor dwell time. There was no clinical follow-up of these patients. Comment: This study confirms that little is gained by post-IVC retrieval venocavography except in the case of a difficult extraction involving forceps or other more invasive devices (w 1% of all cases). Most IVC retrievals, even involving significant force to extract, do not result in major venous injury. The lack of clinical follow-up prevents any interpretation of what this imaging study can tell us regarding patient outcomes as related to the minor abnormalities noted.
Pulmonary Embolism With Right Ventricular Dysfunction: Who Should Receive Thrombolytic Agents? Desai H, Bhupinder N, Bime C, Dill J, Dalen JE, Alpert JS. Am J Med 2017;130:93.e29-93.e32. Conclusion: The results from this study do not support an aggressive use of thrombolytic agents in the stable patient with pulmonary embolism and right ventricular dysfunction. There was no difference in mortality with or without its use as determined by retrospective analysis of the multi-institutional Nationwide Inpatient Sample database. Summary: The hypothesis of this study is that thrombolytic therapy in hemodynamically stable pulmonary embolism (PE) patients with right ventricular dysfunction is not associated with improved survival. This study is a retrospective analysis of the Nationwide Inpatient Sample database. ICD-9 codes were used to identify the patients with PE and right ventricular dysfunction. In-hospital mortality was the primary end point. A total of 3668 patients with PE and acute right heart failure were defined from the 1,227,574 patients with PE observed from 2009-2012. The number of patients who were hemodynamically unstable was 415. Over the years, there was no change in the incidence of PE, average age remained at around 63 years, and the use of thrombolytic therapy (w 0.7%) and surgical embolectomy (w6.5%) also remained stable. The diagnosis of right ventricular failure increased from 2.4 to 3.6 per 1000 patients over the study period. The mortality of stable patients receiving thrombolytic therapy was 8.4% compared to 9.5% without treatment (P ¼ .51) with LOS 8.8 vs 9.6 (P ¼ .5). For the hemodynamically unstable patient, the use of thrombolytic therapy significantly decreased the in-hospital mortality (33% vs 18.1%; P ¼ .0015). The length of stay was unchanged at 9.8 and 11 days respectively (P ¼ .7). The authors note the fact that using a large database has its challenges, such as confirming the clinical situation based on preformed data and ICD codes, its sample-only design, and its tendency to blunt the effect of modifying patient factors that might be important in patient care. Long-term outcomes are not available. Comments: Those stable patients with PE and evidence of right ventricular strain (dysfunction) have been a challenge regarding aggressive thrombolytic treatment. The benefit of clearing the pulmonary arteries to improve the patient’s respiratory status, inpatient mortality, and potentially long-term cardiac function must be balanced against the risk of bleeding (especially intracranial). Being an administrative sample database, it does not provide the detailed patient characteristics that might be important in making clinical decisions for aggressive thrombolysis on an individual basis. It does not provide data regarding the downside of thrombolysis, that being the associated bleeding incidence. It does not provide data on the long-term pulmonary/cardiac effects that thrombolysis might improve and that might be more important in the long run. The study does support the contention that for the majority of hemodynamically stable PE patients with right ventricular dysfunction, the addition of thrombolytic treatment to the care regiment does not improve in-patient mortality.
Time Is Now: Venous Thromboembolism Prophylaxis in Blunt Splenic Injury Kwok AM, Davis JW, Dirks RC, Wolfe MM, Kaups KL. Am J Surg 2016;212:1231-6. Conclusion: Early initiation (<48 hours) of venous thromboembolism (VTE) prophylaxis is safe in patients with blunt splenic trauma being treated non-operatively, and may be safe as early as 24 hours post injury.
Journal of Vascular Surgery: Venous and Lymphatic Disorders
Abstracts
299
Volume 5, Number 2 Summary: This 8 and 1/2-year retrospective level one trauma center study identified patients with blunt splenic trauma. Hemodynamically unstable patients were operated on, angioembolization was performed for extravasation/contrast blush on computed tomography, and others were managed nonoperatively with serial hemoglobin determination. The patients were divided into two groups based on the use of pharmacologic VTE prophylaxis with subgroup analysis based on time of prophylaxis initiation: immediate (<24 hours), early (24-48 hours), intermediate (48-72 hours), and late (>72 hours). Prophylaxis was generally 30-mg enoxaparin every 12 hours or heparin 5000 units every 8 hours in patients with renal insufficiency. VTE was defined as a pulmonary embolism on computed tomography angiography or deep vein thrombosis on duplex imaging obtained because of a high clinical suspicion for VTE. Failure was defined as the need for splenic angioembolization or any splenic operation for the group without VTE prophylaxis, while for those on prophylaxis an additional failure metric of the discontinuation of VTE prophylaxis for a dropping hemoglobin was included. Propensity score matching was used to examine treatment failures between groups. Age, Injury Severity Score (ISS), and grade of splenic injury were used to match patients 1:1. Nine hundred thirty-five patients with splenic injury were discovered, with 438 eliminated due to brain injury, immediate operation, death/ discharge in < 24 hours, transfer in <48 hours, or age <13 years. This left 497 patients, with 256 receiving and 241 not receiving VTE prophylaxis.
Those receiving prophylaxis were older, had higher ISS scores, and had more grade 1 and less grade 4 injuries on a statistical basis and had longer intensive care unit and overall hospital length of stay (more than doubled). Twenty-one patients on VTE prophylaxis failed nonoperative management or required discontinuation of prophylaxis, while 17 in the alternate group failed. The timing of prophylaxis had no impact on the nonoperative failure rate, but there were only 23 patients in the immediate group, while there were greater than 64 in all other treatment groups. The authors only mention the VTE rate in patients on prophylaxis as 2%; the untreated group rate is not mentioned. Propensity-matched comparisons (165 in each group) demonstrated no difference in any category except a 2-day longer length of stay in the prophylaxis-treated patients. Most importantly, the nonoperative failure rate was 12 (7.2%) versus 11 (6.6%) patients in the no prophylaxis vs prophylaxis groups. Comments: This study supports the impression that pharmacologic VTE prophylaxis in patients with splenic trauma is as safe, in terms of preserving nonoperative management, as those not provided prophylaxis. Unfortunately, it does not report the benefit of treatment, that being prevention of VTE in the nontreated patients, which is a major deficiency in the results reported. It also does not explain the longer hospital stays in patient treated with prophylaxis especially when there were more grade 1 splenic injuries in this cohort. We do know that the treated patients had higher ISS scores and so other associated injuries may be in play.
Abstracts
Journal of Vascular Surgery: Venous and Lymphatic Disorders March 2017
the filter is grasped with a snare, and the filter is pulled into the sheath for about 1/4 or 1/3 of its length. Manual negative suction using a 20-mL syringe is applied to the sheath side port as the filter is completely pulled into sheath. The entire sheath, filter, and snare is removed from the femoral vein. Experience has demonstrated that this can be safely accomplished in those with smaller than 3-cm-diameter clots. For those with larger clot burden, CDT (1-7 days) attempted to decrease the thrombus to <2 x 3 cm, at which point aspiration thrombectomy or standard removal could be attempted. If the clot burden could not be reduced, retrieval was abandoned. Two hundred thirty-six cases (30.9%) demonstrated thrombus in the filter in preretrieval venography obtained 12 to 39 days after insertion (average, 16.9 days). A simple snare and sheath technique allowed successful removal in 120 of 121 cases with small clot present. One failure was due to the filter hook being imbedded in the IVC wall. Massive thrombus was present in 97 cases and complete occlusion was present in 18. At the time of retrieval, 97.9% were asymptomatic. Seventy-eight patients with massive filter thrombus received CDT with successful lysis in 55 patients to a small clot burden and 54 were successfully removed with the standard retrieval method. Twenty-three patients had no significant clot regression, 15 were left as a permanent filter, and 8 were retrieved with aspiration thrombectomy. In the other 19 patients, aspiration thrombectomy was successful without the need for additional thrombolysis. All 18 patients with complete occlusion underwent CDT; six filters were ultimately left in place, with the others successfully lysed sufficiently for standard (n ¼ 7) or aspiration thrombectomy (n ¼ 5) removal. No symptomatic PE or DVT progression was noted up to 2 weeks following removal. No major bleeding occurred during CDT, but there were two cases of gross hematuria. Comments: This is likely the largest reported series of filter retrieval in patients with significant thrombus present at time of removal, especially those with massive clot or complete IVC occlusion. Introduction of the aspiration thrombectomy method to aid in retrieval for those with moderate clot burden (<2 x 3 cm) is also interesting and potentially a useful addition to filter retrieval. The lack of PE symptoms following the aspiration technique is reassuring, but the lack of postintervention imaging does not allow an estimate of residual local disease nor a measure of nonclinical PE. This series of patient did require PE prevention and so filter placement was appropriate. Removal after adequate anticoagulation to prevent the known complications associated with long-term filter placement, even on anticoagulation, is known and support retrieval as attempted by these investigators. The PREPIC study is the only randomized controlled study to look at the combined use of filter and anticoagulation to date and note some benefit early with combined therapy but also the long term negative effect of filters. (Decousus H et al. A clinical trial of vena caval filters in the prevention of pulmonary embolism in patients with proximal deep-vein thrombosis. Prevention du Risque d’ Embolie Pulmonaire par Interruption Cave Study Group. N Engl J Med 1998;338:409-15).
Is a Venocavagram Necessary after Inferior Vena Cava Filter Retrieval? Mintz JD, Stavropoulos, 27:1857-64.
Trerotola SO. J Vasc Interv Radiol 2016;
Conclusion: The lack of venographic abnormalities requiring treatment after routine inferior vena cava (IVC) filter retrieval suggests that postintervention venocavography can be eliminated. After difficult retrievals, extravasation requiring treatment may justify continuing its limited use. Summary: This single-institution, 10-year retrospective cohort study involved all 245 patients with successful IVC filter retrieval and having a postretrieval venacavogram. Excluding 22 patients for missing records (four for extensive baseline thrombosis and two due to retrieval within a day) left 228 retrievals (120 routine and 108 complex) in 224 patients (four patients required two filter retrievals). The majority of filters were the Recovery series, Celect, or Gunther Tulip designs. A prior retrieval was attempted in one routine and 73 complex retrieval cases. A complex retrieval was defined as one requiring forceps or other adjuncts beyond a snare or dedicated retrieval device. The only major abnormality after retrieval was extravasation (three cases and only in the complex group). The treatment in each was balloon tamponade to approximate IVC diameter for 5-minute inflations repeated until resolution and then observation. There were more minor abnormalities noted after complex retrievals (n ¼ 85) than routine retrievals (n ¼ 62; P < .001). Minor abnormalities (consisting of stenosis, the most significant being the 51%-75%
category) were noted in 2% vs 6% routine vs complex cases, and spasm and filling defects (not clearly defined but noted as present in 10% routine vs 38% complex cases; P ¼ .001) had no effect on patient management. The frequency of abnormalities did not vary with filter type nor dwell time. There was no clinical follow-up of these patients. Comment: This study confirms that little is gained by post-IVC retrieval venocavography except in the case of a difficult extraction involving forceps or other more invasive devices (w 1% of all cases). Most IVC retrievals, even involving significant force to extract, do not result in major venous injury. The lack of clinical follow-up prevents any interpretation of what this imaging study can tell us regarding patient outcomes as related to the minor abnormalities noted.
Pulmonary Embolism With Right Ventricular Dysfunction: Who Should Receive Thrombolytic Agents? Desai H, Bhupinder N, Bime C, Dill J, Dalen JE, Alpert JS. Am J Med 2017;130:93.e29-93.e32. Conclusion: The results from this study do not support an aggressive use of thrombolytic agents in the stable patient with pulmonary embolism and right ventricular dysfunction. There was no difference in mortality with or without its use as determined by retrospective analysis of the multi-institutional Nationwide Inpatient Sample database. Summary: The hypothesis of this study is that thrombolytic therapy in hemodynamically stable pulmonary embolism (PE) patients with right ventricular dysfunction is not associated with improved survival. This study is a retrospective analysis of the Nationwide Inpatient Sample database. ICD-9 codes were used to identify the patients with PE and right ventricular dysfunction. In-hospital mortality was the primary end point. A total of 3668 patients with PE and acute right heart failure were defined from the 1,227,574 patients with PE observed from 2009-2012. The number of patients who were hemodynamically unstable was 415. Over the years, there was no change in the incidence of PE, average age remained at around 63 years, and the use of thrombolytic therapy (w 0.7%) and surgical embolectomy (w6.5%) also remained stable. The diagnosis of right ventricular failure increased from 2.4 to 3.6 per 1000 patients over the study period. The mortality of stable patients receiving thrombolytic therapy was 8.4% compared to 9.5% without treatment (P ¼ .51) with LOS 8.8 vs 9.6 (P ¼ .5). For the hemodynamically unstable patient, the use of thrombolytic therapy significantly decreased the in-hospital mortality (33% vs 18.1%; P ¼ .0015). The length of stay was unchanged at 9.8 and 11 days respectively (P ¼ .7). The authors note the fact that using a large database has its challenges, such as confirming the clinical situation based on preformed data and ICD codes, its sample-only design, and its tendency to blunt the effect of modifying patient factors that might be important in patient care. Long-term outcomes are not available. Comments: Those stable patients with PE and evidence of right ventricular strain (dysfunction) have been a challenge regarding aggressive thrombolytic treatment. The benefit of clearing the pulmonary arteries to improve the patient’s respiratory status, inpatient mortality, and potentially long-term cardiac function must be balanced against the risk of bleeding (especially intracranial). Being an administrative sample database, it does not provide the detailed patient characteristics that might be important in making clinical decisions for aggressive thrombolysis on an individual basis. It does not provide data regarding the downside of thrombolysis, that being the associated bleeding incidence. It does not provide data on the long-term pulmonary/cardiac effects that thrombolysis might improve and that might be more important in the long run. The study does support the contention that for the majority of hemodynamically stable PE patients with right ventricular dysfunction, the addition of thrombolytic treatment to the care regiment does not improve in-patient mortality.
Time Is Now: Venous Thromboembolism Prophylaxis in Blunt Splenic Injury Kwok AM, Davis JW, Dirks RC, Wolfe MM, Kaups KL. Am J Surg 2016;212:1231-6. Conclusion: Early initiation (<48 hours) of venous thromboembolism (VTE) prophylaxis is safe in patients with blunt splenic trauma being treated non-operatively, and may be safe as early as 24 hours post injury.
Journal of Vascular Surgery: Venous and Lymphatic Disorders
Abstracts
299
Volume 5, Number 2 Summary: This 8 and 1/2-year retrospective level one trauma center study identified patients with blunt splenic trauma. Hemodynamically unstable patients were operated on, angioembolization was performed for extravasation/contrast blush on computed tomography, and others were managed nonoperatively with serial hemoglobin determination. The patients were divided into two groups based on the use of pharmacologic VTE prophylaxis with subgroup analysis based on time of prophylaxis initiation: immediate (<24 hours), early (24-48 hours), intermediate (48-72 hours), and late (>72 hours). Prophylaxis was generally 30-mg enoxaparin every 12 hours or heparin 5000 units every 8 hours in patients with renal insufficiency. VTE was defined as a pulmonary embolism on computed tomography angiography or deep vein thrombosis on duplex imaging obtained because of a high clinical suspicion for VTE. Failure was defined as the need for splenic angioembolization or any splenic operation for the group without VTE prophylaxis, while for those on prophylaxis an additional failure metric of the discontinuation of VTE prophylaxis for a dropping hemoglobin was included. Propensity score matching was used to examine treatment failures between groups. Age, Injury Severity Score (ISS), and grade of splenic injury were used to match patients 1:1. Nine hundred thirty-five patients with splenic injury were discovered, with 438 eliminated due to brain injury, immediate operation, death/ discharge in < 24 hours, transfer in <48 hours, or age <13 years. This left 497 patients, with 256 receiving and 241 not receiving VTE prophylaxis.
Those receiving prophylaxis were older, had higher ISS scores, and had more grade 1 and less grade 4 injuries on a statistical basis and had longer intensive care unit and overall hospital length of stay (more than doubled). Twenty-one patients on VTE prophylaxis failed nonoperative management or required discontinuation of prophylaxis, while 17 in the alternate group failed. The timing of prophylaxis had no impact on the nonoperative failure rate, but there were only 23 patients in the immediate group, while there were greater than 64 in all other treatment groups. The authors only mention the VTE rate in patients on prophylaxis as 2%; the untreated group rate is not mentioned. Propensity-matched comparisons (165 in each group) demonstrated no difference in any category except a 2-day longer length of stay in the prophylaxis-treated patients. Most importantly, the nonoperative failure rate was 12 (7.2%) versus 11 (6.6%) patients in the no prophylaxis vs prophylaxis groups. Comments: This study supports the impression that pharmacologic VTE prophylaxis in patients with splenic trauma is as safe, in terms of preserving nonoperative management, as those not provided prophylaxis. Unfortunately, it does not report the benefit of treatment, that being prevention of VTE in the nontreated patients, which is a major deficiency in the results reported. It also does not explain the longer hospital stays in patient treated with prophylaxis especially when there were more grade 1 splenic injuries in this cohort. We do know that the treated patients had higher ISS scores and so other associated injuries may be in play.