In-situ Bypass Is Associated with Superior Infection-free Survival Compared to Extra-Anatomic Bypass for the Management of Secondary Aortic Graft Infections Without Enteric Involvement

OBJECTIVE

The optimal revascularization modality following complete resection of aortic graft infection (AGI) without enteric involvement remains unclear. The purpose of this investigation is to determine the revascularization approach associated with the lowest morbidity and mortality using real-world data in patients undergoing complete excision of AGI.

METHODS

A retrospective, multi-institutional study of AGI from 2002-2014 was performed using a standardized database. Baseline demographics, comorbidities, and perioperative variables were recorded. The primary outcome was infection-free survival. Descriptive statistics, Kaplan-Meier survival analysis, and univariate and multivariable analyses were performed.

RESULTS

241 patients at 34 institutions from 7 countries presented with AGI during the study period (median age 68 years; 75% male). The initial aortic procedures that resulted in AGI were 172 surgical grafts (71%) and 66 endografts (27%) and 3 unknown (2%). 172 (71%) of the patients underwent complete excision of infected aortic graft material followed by in situ (in-line) bypass (ISB), including antibiotic-treated prosthetic graft (35%), autogenous femoral vein (NAIS) (24%), and cryopreserved allograft (41%). 69 patients (29%) underwent extra-anatomic bypass (EAB). Overall median Kaplan-Meier (KM) estimated survival was 5.8 years. Perioperative mortality was 16%. When stratified by ISB versus EAB, there was a significant difference in KM estimated infection-free survival (2910 days, IQR 391, 3771 versus 180 days, IQR 27, 3750 days; p<0.001). There were otherwise no significant differences in presentation, comorbidities, nor perioperative variables. Multivariable Cox regression showed lower infection-free survival among patients with EAB (HR 2.4, 95% CI 1.6-3.6; p<0.001), polymicrobial infection (HR 2.2, 95% CI 1.4-3.5; p=0.001), MRSA infection (HR 1.7, 95% CI 1.1-2.7; p=0.02), as well as the protective effect of omental/muscle flap coverage (HR 0.59, 95% CI 0.37-0.92; p=0.02).

CONCLUSIONS

After complete resection of AGI, perioperative mortality is 16% and median overall survival is 5.8 years. EAB is associated with nearly a two-and-half fold higher re-infection/mortality compared to ISB. Omental and/or muscle flap coverage of the repair appear protective.

Impact of COVID-19 on the Society for Vascular Surgery Vascular Quality Initiative Venous Procedure Registries (varicose vein and inferior vena cava filter)

In response to the pandemic, an abrupt pivot of Vascular Quality Initiative physician members away from standard clinical practice to a restrictive phase of emergent and urgent vascular procedures occurred. The Society for Vascular Surgery Patient Safety Organization queried both data managers and physicians in May 2020. Approximately three-fourths (74%) of physicians adopted restrictive operating policies for urgent and emergent cases only, whereas one-half proceeded with "time sensitive" elective cases as urgent. Data manager case entry was negatively affected by both low case volumes and staffing due to reassignment or furlough. Venous registry volumes were reduced fivefold in the first quarter of 2020 compared with a similar period in 2019. The consequences of delaying vascular procedures for ambulatory venous practice remain unknown with increased morbidity likely. Challenges to determine venous thromboembolism mortality impact exist given difficulty in verifying "in home and extended care facility" deaths. Further ramifications of a pandemic shutdown will likely be amplified if postponement of elective vascular care extends beyond a short window of time. It will be important to monitor disease progression and case severity as a result of policy shifts adopted locally in response to pandemic surges.

The impact of COVID-19 pandemic on vascular registries and clinical trials

Quality improvement programs and clinical trial research experienced disruption due to the coronavirus disease 2019 (COVID-19) pandemic. Vascular registries showed an immediate impact with significant declines in second-quarter vascular procedure volumes witnessed across Europe and the United States. To better understand the magnitude and impact of the pandemic, organizations and study groups sent grass roots surveys to vascular specialists for needs assessment. Several vascular registries responded quickly by insertion of COVID-19 variables into their data collection forms. More than 80% of clinical trials have been reported delayed or not started due to factors that included loss of enrollment from patient concerns or mandated institutional shutdowns, weighing the risk of trial participation on patient safety. Preliminary data of patients undergoing vascular surgery with active COVID-19 infection show inferior outcomes (morbidity) and increased mortality. Disease-specific vascular surgery study collaboratives about COVID-19 were created for the desire to study the disease in a more focused manner than possible through registry outcomes. This review describes the pandemic effect on multiple VASCUNET registries including Germany (GermanVasc), Sweden (SwedVasc), United Kingdom (UK National Vascular Registry), Australia and New Zealand (bi-national Australasian Vascular Audit), as well as the United States (Society for Vascular Surgery Vascular Quality Initiative). We will highlight the continued collaboration of VASCUNET with the Vascular Quality Initiative in the International Consortium of Vascular Registries as part of the Medical Device Epidemiology Network coordinated registry network. Vascular registries must remain flexible and responsive to new and future real-world problems affecting vascular patients.

Effects of coronavirus disease 2019 on the Society for Vascular Surgery Vascular Quality Initiative arterial procedure registry

In the present report, we have described the abrupt pivot of Vascular Quality Initiative physician members away from standard clinical practice to a restrictive phase of emergent and urgent vascular procedures in response to the coronavirus disease 2019 (COVID-19) pandemic. The Society for Vascular Surgery Patient Safety Organization queried both data managers and physicians in May 2020 to discern the effects of the COVID-19 pandemic. Approximately three fourths of physicians (74%) had adopted a restrictive operating policy for urgent and emergent cases only. However, one half had considered “time sensitive” elective cases as urgent. Data manager case entry was affected by both low case volumes and low staffing resulting from reassignment or furlough. A sevenfold reduction in arterial Vascular Quality Initiative case volume entry was noted in the first quarter of 2020 compared with the same period in 2019. The downstream consequences of delaying vascular procedures for carotid artery stenosis, aortic aneurysm repair, vascular access, and chronic limb ischemia remain undetermined. Further ramifications of the COVID-19 pandemic shutdown will likely be amplified if resumption of elective vascular care is delayed beyond a short window of time.

Aggressive Surveillance Is Needed to Detect Endoleaks and Junctional Separation between Device Components after Zenith Fenestrated Aortic Reconstruction

BACKGROUND

Junctional separation and resulting type IIIa endoleak is a well-known problem after EVAR (endovascular aneurysm repair). This complication results in sac pressurization, enlargement, and eventual rupture. In this manuscript, we review the incidence of this late finding in our experience with the Cook Zenith fenestrated endoprosthesis (ZFEN, Bloomington, IN).

METHODS

A retrospective review was performed of a prospectively maintained institutional ZFEN fenestrated EVAR database capturing all ZFENs implanted at a large-volume, academic hospital system. Patients who experienced junctional separation between the fenestrated main body and distal bifurcated graft (with or without type IIIa endoleak) at any time after initial endoprosthesis implantation were subject to further evaluation of imaging and medical records to abstract clinical courses.

RESULTS

In 110 ZFENs implanted from October 2012 to December 2017 followed for a mean of 1.5 years, we observed a 4.5% and 2.7% incidence of clinically significant junctional separation and type IIIa endoleak, respectively. Junctional separation was directly related to concurrent type Ib endoleak in all 5 patients. Three patients presented with sac enlargement. One patient did not demonstrate any evidence of clinically significant endoleak and had a decreasing sac size during follow-up imaging. The mean time to diagnosis of modular separation in these patients was 40 months. Junctional separation was captured in surveillance in 2 patients and reintervened upon before manifestation of endoleak. However, the remaining 3 patients completed modular separation resulting in rupture and emergent intervention in 2 and an aortic-related mortality in the other.

CONCLUSIONS

Junctional separation between the fenestrated main and distal bifurcated body with the potential for type IIIa endoleak is an established complication associated with the ZFEN platform. Therefore, we advocate for maximizing aortic overlap during the index procedure followed by aggressive surveillance and treatment of stent overlap loss captured on imaging.

Long-term outcomes after pediatric peripheral revascularization secondary to trauma at an urban level I center

OBJECTIVE

The purpose of this investigation was to determine our limb-related contemporary pediatric revascularization perioperative and follow-up outcomes after major blunt and penetrating trauma.

METHODS

A retrospective review was performed of a prospectively maintained pediatric trauma database spanning January 2010 to December 2017 to capture all level I trauma activations that resulted in a peripheral arterial revascularization procedure. All preoperative, intraoperative, and postoperative continuous variables are reported as a mean ± standard deviation; categorical variables are reported as a percentage of the population of interest.

RESULTS

During the study period, 1399 level I trauma activations occurred at a large-volume, urban children's hospital. The vascular surgery service was consulted in 2.6% (n = 36) of these cases for suspected vascular injury based on imaging or physical examination. Our study population included only patients who received an arterial revascularization, which was performed in 23 of the 36 consultations (1.6% of total traumas; median age, 11 years). These injuries were localized to the upper extremity in 60.9% (n = 14), lower extremity in 30.4% (n = 7), and neck in 8.7% (n = 2). The mean Injury Severity Score in the revascularized cohort was 14.0 (±7.6). Bone fractures were associated with 39.1% of the vascular injuries (90% of blunt injuries). Restoration of in-line flow was achieved by an endovascular solution in one patient and open surgery in the remainder, consisting of arterial bypass in 59.1% and direct repair in 40.9%. Within 30 days of the operation, we observed no deaths, no infections of the arterial reconstruction, and no major amputations. One patient required perioperative reintervention by the vascular team secondary to the development of a superficial seroma without evidence of graft involvement. Mean follow-up in our cohort was 43.3 (±35.4) months. During this phase, no additional deaths, amputations, chronic wounds, or limb length discrepancies were observed. All vascular repairs were patent, and all but one patient reported normal function of the affected limb at the latest clinic visit.

CONCLUSIONS

Traumatic peripheral vascular injury is rare in the pediatric population but is often observed secondary to a penetrating force or after long bone fracture. However, contemporary perioperative and long-term outcomes after surgical revascularization are excellent as demonstrated in this institutional case series.

Cryopreserved Homografts in Infected Infrainguinal Fields Are Associated with Frequent Reinterventions and Poor Amputation-Free Survival

BACKGROUND

Single-length saphenous vein continues to be the conduit of choice in infected-field critical limb ischemia. However, half of these individuals have inadequate vein secondary to previous use or chronic venous disease. We reviewed our outcomes of infected-field infrainguinal bypasses performed with cryopreserved homografts (CHs), a widely accepted alternative to autogenous vein in this setting.

METHODS

This is a retrospective, institutional descriptive analysis of infected-field infrainguinal revascularizations between 2012 and 2015.

RESULTS

Twenty-four operations were performed in the same number of patients for limb ischemia with signs of active infection. The mean age of the cohort examined was 62.5 ± 14.4 (standard deviation) years. Mean Society of Vascular Surgery risk score was 3.9 with a baseline Rutherford's chronic ischemia score of 4.3 at presentation. Emergent procedures constituted 29% of cases, and the remainder cases were urgent procedures. The CH bypass captured was a reoperative procedure in all but one of the patients. Culture positivity was present in 75% of cases with Staphylococcus aureus (29%), the most commonly isolated organism. Thirty-day mortality and major adverse cardiovascular events were both 4%. Amputation-free survival (AFS) was 75% at 30 days. Similarly, 30-day reintervention was 38% with debridement (43%) and bleeding (29%), the most common indications. Average duration of follow-up was 27.9 ± 20.4 months (range: 0.5-60.4). Mean length of stay was 14.8 days. Reinfection requiring an additional procedure or antibiotic regimen separate from the index antibiotic course was 13%. Primary patency and AFS at 1 year was 50% and 58%, respectively. Primary patency and AFS at 2 years was 38% and 52%, respectively. Limb salvage at 1 and 2 years was 70% and 65%, respectively. Fifteen patients (63%) required reintervention during the follow-up period with 40% of those subjects undergoing multiple procedures.

CONCLUSIONS

CHs remain a marginal salvage conduit in the setting of infection and no autogenous choices. Therefore, clinicians should individualize usage of this high-cost product in highly selected patients only.

Staged endovascular repair of an abdominal aortic aneurysm adjacent to a chronic high-flow iliocaval traumatic arteriovenous fistula

Large-vessel chronic traumatic arteriovenous fistulas are a rare complication after trauma. Delayed presentation can consist of one or more features of high-output cardiac failure, pulsatile abdominal mass, bruit, limb ischemia, and venous congestion. We describe a patient with a complex iliocaval fistula secondary to a remote gunshot wound associated with a large 8.5-cm aortic aneurysm. Informed consent of the patient was obtained for publication of the case.

Cryopreserved venous allograft is an acceptable conduit in patients with current or prior angioaccess graft infection

OBJECTIVE

The durability of cryopreserved allograft has been previously demonstrated in the setting of infection. The objective of this study was to examine the safety, efficacy, patency, and cost per day of graft patency associated with using cryopreserved allograft (vein and artery) for hemodialysis access in patients with no autogenous tissue for native fistula creation and with arteriovenous graft infection or in patients at high risk for infection.

METHODS

Patients implanted with cryopreserved allograft for hemodialysis access between January 2004 and January 2014 were reviewed using a standardized, multi-institutional database that evaluated demographic, comorbidity, procedural, and outcomes data.

RESULTS

There were 457 patients who underwent placement of cryopreserved vein (femoral: n = 337, saphenous: n = 11) or artery (femoral: n = 109) for hemodialysis access at 20 hospitals. Primary indications for allograft use included high risk of infection in 191 patients (42%), history of infected prosthetic graft in 169 (37%), and current infection in 97 (21%). Grafts were placed more frequently in the arm (78%) than in the groin, with no difference in allograft conduit used. Mean time from placement to first hemodialysis use was 46 days (median, 34 days). Duration of functional graft use was 40 ± 7 months for cryopreserved vein and 21 ± 8 months for cryopreserved artery (P < .05), and mean number of procedures required to maintain patency at follow-up of 58 ± 21 months was 1.6 for artery and 0.9 for vein (P < .05). Local access complications occurred in 32% of patients and included late thrombosis (14%), graft stenosis (9%), late infection (9%), arteriovenous access malfunction (7%), early thrombosis (3%), and early infection (3%). Early and late infections both occurred more frequently in the groin (P = .030, P = .017, respectively), and late thrombosis occurred more frequently with cryopreserved artery (P < .001). Of the 82 patients (18%) in whom the cryopreserved allograft was placed in the same location as the excised infected prosthetic graft, 13 had infection of the allograft during the study period (early: n = 4; late: n = 9), with no significant difference in infection rate (P = .312) compared with the remainder of the study population. The 1-, 3-, and 5-year primary patency was 58%, 35%, and 17% for cryopreserved femoral vein and 49%, 17%, and 8% for artery, respectively (P < .001). Secondary patency at 1, 3, and 5 years was 90%, 78%, and 58% for cryopreserved femoral vein and 75%, 53%, and 42% for artery, respectively (P < .001). Mean allograft fee per day of graft patency was $4.78 for cryopreserved vein and $6.97 for artery (P < .05), excluding interventional costs to maintain patency.

CONCLUSIONS

Cryopreserved allograft provides an excellent conduit for angioaccess when autogenous tissue is not available in patients with current or past conduit infection. Cryopreserved vein was associated with higher patency and a lower cost per day of graft patency. Cryopreserved allograft allows for immediate reconstruction through areas of infection, reduces the need for staged procedures, and allows early use for dialysis.

Variation in hospital costs and reimbursement for endovascular aneurysm repair: A Vascular Quality Initiative pilot project

OBJECTIVE

Comparing costs between centers is difficult because of the heterogeneity of vascular procedures contained in broad diagnosis-related group (DRG) billing categories. The purpose of this pilot project was to develop a mechanism to merge Vascular Quality Initiative (VQI) clinical data with hospital billing data to allow more accurate cost and reimbursement comparison for endovascular aneurysm repair (EVAR) procedures across centers.

METHODS

Eighteen VQI centers volunteered to submit UB04 billing data for 782 primary, elective infrarenal EVAR procedures performed by 108 surgeons in 2014. Procedures were categorized as standard or complex (with femoral-femoral bypass or additional arterial treatment) and without or with complications (arterial injury or embolectomy; bowel or leg ischemia; wound infection; reoperation; or cardiac, pulmonary, or renal complications), yielding four clinical groups for comparison. MedAssets, Inc, using cost to charge ratios, calculated total hospital costs and cost categories. Cost variation analyzed across centers was compared with DRG 237 (with major complication or comorbidity) and 238 (without major complication or comorbidity) coding. A multivariable model to predict DRG 237 coding was developed using VQI clinical data.

RESULTS

Of the 782 EVAR procedures, 56% were standard and 15% had complications, with wide variation between centers. Mean total costs ranged from $31,100 for standard EVAR without complications to $47,400 for complex EVAR with complications and varied twofold to threefold among centers. Implant costs for standard EVAR without complications varied from $8100 to $28,200 across centers. Average Medicare reimbursement was less than total cost except for standard EVAR without complications. Only 9% of all procedures with complications in the VQI were reported in the higher reimbursed DRG 237 category (center range, 0%-21%). There was significant variation in hospitals' coding of DRG 237 compared with their expected rates. VQI clinical data accurately predict current DRG coding (C statistic, 0.87).

CONCLUSIONS

VQI data allow a more precise EVAR cost comparison by identifying comparable clinical groups compared with DRG-based calculations. Total costs exceeded Medicare reimbursement, especially for patients with complications, although this varied by center. Implant costs also varied more than expected between centers for comparable cases. Incorporation of VQI data elements documenting EVAR case complexity into billing data may allow centers to better align respective DRG reimbursement to total costs.

Institutional Cost of Unplanned 30-Day Readmission Following Open and Endovascular Surgery

Background:

Vascular surgical patients have a high rate of readmission, and the cost of readmission for these patients has not been described. Herein, we characterize and compare institutional index hospitalization and 30-day readmission cost following open and endovascular vascular procedures.

Methods:

The American College of Surgeons National Surgical Quality Improvement Program database was used to identify inpatient open and endovascular procedures at a single institution, from January 2011 through June 2012. Variable and fixed costs for index hospitalization and unplanned 30-day readmissions were obtained using SAP BusinessObjects. Patient characteristics and outcome variables were analyzed using Student t tests or Wilcoxon rank-sum nonparametric tests for continuous variables and Fisher exact tests for categorical variables.

Results:

One thousand twenty-six inpatient procedures were included in the analysis. There were 605 (59%) open and 421 (41%) endovascular procedures with a 30-day unplanned readmission rate of 16.9% and 17.8%, respectively ( P = .679). The mean index hospitalization costs for open and endovascular procedures were US$27 653 and US$23 999, respectively ( P = .146). The mean costs for 30-day unplanned readmission for open and endovascular procedures were US$19 117 and US$17 887, respectively ( P = .635). Among open procedures, the mean cost for patients not readmitted was US$28 321 compared to US$31 115 for those readmitted ( P = .003). Among endovascular procedures, the mean cost for patients not readmitted was US$26 908 compared to US$32 262 for those readmitted ( P = .028).

Conclusion:

The cost of index hospitalization and 30-day unplanned readmission are similar for open and endovascular procedures. Readmitted patients had a higher mean index hospitalization cost irrespective of open or endovascular procedure.

A vascular laboratory protocol for improving and managing after-hours suspected acute deep venous thrombosis

This study reviews the clinical and workforce impact of a suggested protocol designed for the management of suspected acute deep venous thrombosis (DVT) in patients seen after standard vascular laboratory business hours. The protocol included the use of Wells score, D-dimer and a single dose of therapeutic anticoagulant to defer venous duplex ultrasound (VDU) testing until routine business hours unless contraindicated. Information was collected on medical history, physical exam and the timing of any diagnostic studies and treatment provided. Over 15% of studies done after-hours were deemed unnecessary by our protocol and in every individual the results were negative for an acute DVT. There were no adverse events from a one-time dose of anticoagulant. Limiting emergency VDU coverage to evaluate for acute DVT based on a management protocol can eliminate unnecessary after-hours VDU testing without having a negative impact on patient care.

Dialysis access steal syndromes

Dialysis-associated steal syndromes remain a vexing problem for the busy vascular access surgeon. Those factors associated with ischemia include the elderly, diabetic, female, preexisting cardiac disease and brachial anastomosis, and previous ipsilateral access. A constellation of symptoms and findings based on underlying arterial disease and flow characteristics are necessary to provide prompt diagnosis and initiate treatment. Although a digital brachial index (DBI) >1 and transcutaneous oxygen tension (TCPO(2) ) measurements >60 mm Hg accurately predict a patient not at risk, no DBI or TCPO2 levels below that accurately predict if a patient will develop dialysis-associated ischemia. The goal of the vascular access surgeon is to provide prompt recognition and treatment of the disorder to maximize both limb salvage and access salvage. Continuation of angio access in the same extremity can be accomplished in most individuals.

Incomplete caval protection following suprarenal caval filter placement--a case report

Inferior vena cava filters are increasingly utilized to prevent pulmonary emboli originating from lower extremity, pelvis, or caval thromboses. Unique indications exist for filter placement in the suprarenal portion of the vena cava. The largest reported experience in suprarenal position has involved the use of the Greenfield filter. Although unique in design, little differences have been described between the stainless steel and titanium version of this device. The authors present a case report of incomplete caval protection after successful placement of a stainless steel Greenfield filter in the suprarenal cava. Subtle differences between the titanium and the stainless steel Greenfield filter may exist and should be taken into consideration for placement in the suprarenal cava. Physiologic conditions supporting this premise are described. Further investigation between the two filter types appears justified.

Pressure Control Inverse Ratio Ventilation in the Treatment of Adult Respiratory Distress Syndrome in Patients with Blunt Chest Trauma

The objective of this study was to evaluate the efficacy of pressure control inverse ratio ventilation (PCIRV) in improving oxygenation in trauma patients with adult respiratory distress syndrome (ARDS) and to assess the potential risks associated with this form of treatment. This was a cohort study assessing the trends in hemodynamic and ventilatory parameters after the initiation of PCIRV, conducted at a community Level I trauma center intensive care unit. The study comprised 15 trauma patients developing severe, progressive ARDS [two or more of the following criteria: positive end-expiratory pressure (PEEP) >10 cm H2O; arterial partial pressure of oxygen divided by fraction of inspired oxygen (PaO2:FiO2) ratio <150; and peak inspiratory pressure (PIP) >45 cm H2O]: ten due to blunt chest injuries, three due to sepsis, and two due to fat emboli syndrome. PCIRV was initiated. Main outcome measures were PIP, PEEP (total, auto), oxygen saturation, cardiac index, oxygen delivery, PaO2:FiO2 ratio, compliance, evidence of complications of PCIRV, and mortality. Within 24 hours of conversion to PCIRV, the patients stabilized and the mean PaO2:FiO2 ratio rose from 96.3 ± 57.8 to 146.8 ± 91.1 (P < 0.05) and PIP fell from 47.9 ± 13.8 to 38.8 ± 8.4 cm H2O; auto-PEEP increased from 0.5 ± 1.9 to 7.5 ± 5.6 cm H2O (P < 0.05); oxygen delivery index remained stable (563 ± 152 to 497 ± 175 mL/min/m2); three patients developed evidence of barotrauma, one patient developed critical illness polyneuropathy, and two patients died (13%). PCIRV is an effective salvage mode of ventilation in patients with severe ARDS, but it is not without complications. Auto-PEEP levels and cardiac index should be monitored to ensure tissue oxygen delivery is maintained.

Pressure control inverse ratio ventilation in the treatment of adult respiratory distress syndrome in patients with blunt chest trauma

The objective of this study was to evaluate the efficacy of pressure control inverse ratio ventilation (PCIRV) in improving oxygenation in trauma patients with adult respiratory distress syndrome (ARDS) and to assess the potential risks associated with this form of treatment. This was a cohort study assessing the trends in hemodynamic and ventilatory parameters after the initiation of PCIRV, conducted at a community Level I trauma center intensive care unit. The study comprised 15 trauma patients developing severe, progressive ARDS [two or more of the following criteria: positive end-expiratory pressure (PEEP) >10 cm H2O; arterial partial pressure of oxygen divided by fraction of inspired oxygen (PaO2:FiO2) ratio <150; and peak inspiratory pressure (PIP) >45 cm H2O]: ten due to blunt chest injuries, three due to sepsis, and two due to fat emboli syndrome. PCIRV was initiated. Main outcome measures were PIP, PEEP (total, auto), oxygen saturation, cardiac index, oxygen delivery, PaO2:FiO2 ratio, compliance, evidence of complications of PCIRV, and mortality. Within 24 hours of conversion to PCIRV, the patients stabilized and the mean PaO2:FiO2 ratio rose from 96.3+/-57.8 to 146.8+/-91.1 (P<0.05) and PIP fell from 47.9+/-13.8 to 38.8+/-8.4 cm H2O; auto-PEEP increased from 0.5+/-1.9 to 7.5+/-5.6 cm H2O (P<0.05); oxygen delivery index remained stable (563+/-152 to 497+/-175 mL/min/m2); three patients developed evidence of barotrauma, one patient developed critical illness polyneuropathy, and two patients died (13%). PCIRV is an effective salvage mode of ventilation in patients with severe ARDS, but it is not without complications. Auto-PEEP levels and cardiac index should be monitored to ensure tissue oxygen delivery is maintained.

Traditional criteria for observation of splenic trauma should be challenged

Age less than 55 years, normal Glasgow Coma Score (GCS), and absence of hypotension are traditional criteria for the selection of adult patients with blunt splenic trauma for observation. The objective of this study is to challenge these criteria. Two hundred twelve patients who presented with blunt splenic injury between 1992 and 1997 were identified from the Trauma Registry at our Level I trauma center. The patients were divided into three groups: 100 patients (47%) were observed, 108 (51%) underwent immediate splenorrhaphy or splenectomy, and 4 (2%) failed observation. The three groups were compared by participants' ages, GCSs, and histories of hypotension. No statistical differences were noted between the successfully observed patients and those requiring immediate surgery with respect to these criteria. Of the 4 patients who failed observation, all were younger than 55 years, all had a GCS >12, and all were normotensive. Our findings suggest that traditional criteria used to select patients for splenic trauma observation are not absolute indicators and should be liberalized: patients can be successfully observed despite having criteria that, in the past, would have led to immediate operative intervention.

Traditional Criteria for Observation of Splenic Trauma Should be Challenged

Age less than 55 years, normal Glasgow Coma Score (GCS), and absence of hypotension are traditional criteria for the selection of adult patients with blunt splenic trauma for observation. The objective of this study is to challenge these criteria. Two hundred twelve patients who presented with blunt splenic injury between 1992 and 1997 were identified from the Trauma Registry at our Level I trauma center. The patients were divided into three groups: 100 patients (47%) were observed, 108 (51%) underwent immediate splenorrhaphy or splenectomy, and 4 (2%) failed observation. The three groups were compared by participants’ ages, GCSs, and histories of hypotension. No statistical differences were noted between the successfully observed patients and those requiring immediate surgery with respect to these criteria. Of the 4 patients who failed observation, all were younger than 55 years, all had a GCS >12, and all were normotensive. Our findings suggest that traditional criteria used to select patients for splenic trauma observation are not absolute indicators and should be liberalized: patients can be successfully observed despite having criteria that, in the past, would have led to immediate operative intervention.

Improved selection criteria for ordering stat venous ultrasounds from the emergency department

BACKGROUND

The accuracy and convenience of venous ultrasound (VU) to exclude deep vein thrombosis (DVT) has led to indiscriminate use and low positive yield rates.

METHODS

A total of 256 patients were referred from our emergency department (ED) for stat VU during a 2-year period (1995 to 1996). The VUs were interpreted as normal in 198 (77%). Positive findings were discovered in 58 (23%), with DVT accounting for 43 (17%). Retrospective multivariant analysis was used to identify predictive indicators.

RESULTS

Unilateral leg swelling/edema identified 36 of 40 (90%) patients with DVT and 8 of 10 (80%) with other thrombotic disorders (saphenous and/or chronic venous thrombosis). A history of leg pain with prior DVT or recent trauma < or =3 days' duration increased DVT duration to 98% (39 of 40). Using these criteria, a 47% charge reduction would have been recognized.

CONCLUSIONS

Improving ED screening criteria can safely increase yield rate and reduce charges with minimal loss of VU sensitivity.

Traumatic lumbar hernia: a seat belt injury

A motor vehicle passenger sustained an acute traumatic lumbar hernia caused by an improperly positioned seat belt. Diagnosis was confirmed on computed tomographic scan, and the defect repaired primarily.

Determination of brain death with use of color duplex scanning in the intensive care unit setting

OBJECTIVE

To determine if color flow duplex scanning (CFDS) can be used for rapid confirmation of presumed brain death.

DESIGN

Pilot cohort study comparison of CFDS with radionuclide cerebral scanning (RCS) as the criterion standard.

SETTING

Community-based level I trauma center intensive care unit.

PATIENTS

Twenty-four patients who satisfied criteria for presumed brain death.

MAIN OUTCOME MEASURE

Confirmation of presumed brain death.

RESULTS

CFDS correctly identified 16 of 24 patients as brain dead, confirmed by RCS. Eight patients with brain flow on RCS were also correctly identified by CFDS. Only two of 24 patients survived their severe injuries.

CONCLUSIONS

CFDS provides a uniform, cost-effective diagnostic tool for rapid confirmation of clinical brain death with 100% accuracy. Its use should complement RCS, given its rapid interpretation, portability, and economical assessment of presumed brain death.

Risk of pulmonary emboli in patients with pelvic fractures

Multiply-injured patients with pelvic fractures are recognized to have an increased risk of deep venous thrombosis. The incidence of pulmonary emboli in patients with this injury has been reported to range from 0.5 to 8.3 per cent in several recent reviews. One hundred ninety-eight patients with pelvic fractures treated at a regional trauma center over a 3-year period were reviewed to evaluate the factors associated with an increased risk of clinically evident pulmonary embolism. The mean age SD was 44 24 years; 51 per cent were male, and mean Injury Severity Score (ISS) was 19 15. Eighteen patients (9%) died. Mortality was significantly correlated with ISS (P < 0.05), male sex, and type and severity of fracture but not with age, mechanism of injury, or operative fixation. Four patients (2.0%) had pulmonary emboli. The occurrence of clinically apparent pulmonary emboli correlated only with ISS (ISS < 15 = 0% vs ISS > 15 = 4%, P < 0.05). During the same time period, there were eight (0.2%) pulmonary emboli in 3337 trauma patients without pelvic fracture. This difference is highly significant (P < 0.0001). Pelvic fracture is indicative of severe injury and denotes a population at higher risk for pulmonary emboli than other trauma patients. Intensive screening and prophylactic measures to prevent deep venous thrombosis and subsequent pulmonary emboli should be intensively directed at this population.

Prophylactic placement of vena caval filters: a cautionary note

Greenfield filter placement in patients without deep venous thrombosis has been performed when such patients were felt to be at high risk for asymptomatic deep venous thrombosis and subsequent embolus. In this group placement is termed "truly prophylactic" to differentiate from placement in a patient with documented deep venous thrombosis which has not yet embolized. A retrospective review of Greenfield filter placement at five Dayton, Ohio, community hospitals over three years revealed 59 filters placed in 58 patients. Of these 90% were placed surgically and 10% percutaneously at an average cost of $4,141.00 per surgical procedure. Indications included traditional as well as true prophylaxis. A low morbidity and no mortality related to filter placement was observed. The high efficacy and safety of filter placement seen at large institutions is also found in our community hospital experience despite placement by physicians who perform the procedure infrequently. Although filter placement in patients at a high risk for silent fatal pulmonary emboli may prevent a rare mortality, widespread use of this modality for pulmonary embolus prophylaxis is costly and not without patient risk. We caution against the use of Greenfield filters for pulmonary embolus prophylaxis in patients without deep venous thrombosis until evidence of superior efficacy compared to other forms of prophylaxis can be demonstrated.