An Opioid-Sparing Protocol Improves Recovery Time and Reduces Opioid Use After Laparoscopic Sleeve Gastrectomy.

PURPOSE: The current literature is sparse on post discharge pain management for bariatric surgical patients. This study aimed to determine if an opioid-sparing protocol could decrease opioid use during the postoperative period (hospital to home). MATERIALS AND METHODS: In this retrospective cohort study, we implemented an opioid-sparing protocol in January 2018, for patients undergoing laparoscopic sleeve gastrectomy (LSG) at our institution. We compared recovery time, pain scores (in hospital and at home), and perioperative opioid use between the historic control group (February 2017 to December 2017) and the opioid-sparing group (January 2018 to December 2018). A p value of < .05 was considered statistically significant. RESULTS: The study included 400 patients (200 in each group), and 165 participated in the phone survey. Baseline characteristics were similar, except the control group had a higher body mass index and body weight. The average recovery time was significantly shorter in the opioid-sparing group (18.9 versus 35.3 days, P = .043). There was no significant difference in mean postoperative pain scores in the hospital or at home. The opioid-sparing group required significantly fewer opioids postoperatively (10.4 versus 16.1 morphine milligram equivalents, P < .001). Only 1 out of the 200 patients in the opioid-sparing arm requested an opioid prescription after discharge. CONCLUSION: Implementation of an opioid-sparing protocol improved recovery time and reduced postoperative opioid use in the hospital and after discharge without changing perceived pain in patients undergoing LSG.

Pedicle screws adjacent to the great vessels or viscera: a study of 2132 pedicle screws in pediatric spine deformity.

STUDY DESIGN: A retrospective study. OBJECTIVE: To determine the incidence of pedicle screws close to vital structures and to identify patient or curve characteristics that increase the risk of screw misplacement. SUMMARY AND BACKGROUND: Most pedicle screw misplacements are asymptomatic, thus they are frequently undetected. This study identifies the rate of screw placement in proximity to vital structures using postoperative computed tomography scans. METHODS: A total of 2132 screws in 101 patients, who underwent posterior spinal fusion for spinal deformity, were reviewed. Screws adjacent to great vessels and viscera were identified and evaluated. Patients with screws at risk (group B) were compared with patients without screws at risk (group A). Patient and curve characteristics were analyzed to determine whether a correlation with screw misplacement exists. RESULTS: A total of 40 at risk screws (∼2%) were identified in 25 patients (∼25%). These 40 screws were in proximity to the aorta (31), left subclavian artery (1), esophagus (3), trachea (3), pleura (1), and diaphragm (1). Of the 31 screws close to the aorta, 10 screws in 6 patients were impinging or distorting the aortic wall. One hundred percent of misplaced screws were in the thoracic spine, 50% were misplaced laterally, 50% were 35 mm long, 57.5% were in pedicles with normal morphology, and 75% were in curves between 40 and 70 degrees. Median screw misplacement rate was 10% in group A and 13% in group B. Adjusted for age and preoperative Cobb angle, patients with a higher misplacement rate were more likely to have screws adjacent to vital organs [adjusted odds ratio: 1.06 (95% confidence interval, 1.01-1.13), P=0.033]. CONCLUSIONS: Although only a small number of screws were at risk, they occurred in a large percentage of patients (25%). A single at-risk screw causes a significant complication for the patient. Postoperative imaging beyond routine x-rays may be needed to detect at-risk screws in asymptomatic patients.

Is the length of follow-up evaluation in published reports on the treatment of infrainguinal occlusive disease decreasing?

BACKGROUND: There is increasing pressure for the rapid development and implementation of new techniques and procedures. This study examined whether or not there has been a trend toward increasingly short follow-up times for studies evaluating the treatment of lower-extremity occlusive disease. METHODS: A search was performed of PubMed using the term "femoropopliteal occlusive disease" from 1976 to 2006. Reports describing the open and/or endovascular treatment of femoropopliteal occlusive disease were classified according to the number of patients, method of treatment, and follow-up time. RESULTS: A total of 103 of the 435 reports met the inclusion criteria. Average follow-up times from 1976 to 1986 were a mean of 43.3 months and a median of 38.8 months, from 1986 to 1996 were a mean of 32.4 months and a median of 16.9 months, from 1996 to 2006 were a mean of 22.6 months and a median of 16.5 months. CONCLUSIONS: The number of reports on femoropopliteal occlusive disease treatment has increased. The length of follow-up period was 2- to 3-fold longer for reports on open procedures compared with those on endovascular procedures. Whether length of follow-up evaluation and reporting intervals should be standardized warrants further investigation.

Incidence and characteristics of venous thromboembolic disease during pregnancy and the postnatal period: a contemporary series.

BACKGROUND: To evaluate the incidence and characteristics of venous thromboembolic events (VTE) associated with pregnancy in a contemporary patient series. METHODS: We performed a retrospective review of 33,311 deliveries between June 2003 and June 2008. Patients with objective documentation of a VTE during pregnancy or the 3-month postnatal period were identified from hospital discharge International Classification of Disease Codes edition 9 codes. Diagnosis of deep venous thrombosis (DVT) was largely made by a Duplex ultrasound, whereas pulmonary embolism (PE) was diagnosed by a computerized tomographic angiography (CTA). RESULTS: Of 33,311 deliveries during the study period, 74 patients (0.22%) had a VTE. There were 40 incidents of DVT (0.12%) and 37 of PE (0.11%). DVT involved the iliac veins (6), the femoral or popliteal veins (16), the infrapopliteal veins (17), and the axillary vein (1). Most (57.5%) of the DVTs involved the left lower extremity. Thirty-eight (51.6%) of the VTEs occurred in the postnatal period, and of those 33 (87%) occurred within 1 week of delivery. Most of the postnatal VTEs (68%) were seen in patients who underwent a cesarean section. Among patients with VTE during pregnancy, there were 28% in the first trimester, 25% in the second, and 47% in the third. Events were distributed among maternal age groups as follows: 26% aged 13-24, 50% aged 25-34, and 24% aged 35-54. Of the 35 patients tested for a hypercoagulable disorder, 12 were found to have a positive test result. Five (6.8%) of these 74 patients had a prior history of VTE, with two having a hypercoagulable disorder. In addition, 45 of the 74 patients were on oral contraceptive therapy or received hormonal stimulation therapy before pregnancy. Patients with a VTE during pregnancy were treated with low molecular weight or unfractionated heparin. Most postnatal patients were treated with subcutaneous low molecular weight heparin and coumadin. Six inferior vena cava filters were placed in patients with bleeding complications as a result of anticoagulation. There were no deaths during the study period. CONCLUSIONS: Comparing our results with historic controls (DVT: 0.04-0.14% and PE: 0.003-0.04%), the incidence of DVT in pregnancy has not changed significantly. We note, however, that the incidence of pulmonary embolus in our series is higher than previously reported. CTA has been used for the diagnosis of PE since the past decade. The increase in the rate of PE in the current series may be because of the higher sensitivity of CTA when compared with previous diagnostic modalities.

Long-term outcome of inferior vena cava filter placement in patients undergoing gastric bypass.

BACKGROUND: It has been well established that inferior vena cava (IVC) filter placement at the time of open gastric bypass (OGB) surgery in patients with a body mass index of more than 55 kg/m(2) reduces both the pulmonary embolism rate and the perioperative mortality. However, little is known about the long-term effects of IVC filter placement in this particular group of patients. METHODS: Over an 8-year period, a total of 571 morbid obese patients underwent OGB procedures, and 58 (10%) of them required placement of an IVC filter before their procedure. All IVC filters were placed percutaneously through a femoral vein approach using a portable OEC fluoroscope. Types of IVC filters used in our study included the TrapEase (n = 35), Simon-Nitinol (n = 9), Greenfield (n = 2), and Bard Recovery (n = 12). RESULTS: Of the 58 patients who required an IVC placement, 56 remained free of any thromboembolic phenomena over the 8-year period (range, 1-8 years). The remaining two patients developed deep venous thrombosis. One patient was successfully treated with intravenous heparin and a 6-month course of Coumadin. She had complete resolution of her deep venous thrombosis and was incidentally noted to have a prothrombin 20210 gene mutation. The other patient, who had multiple gastric bypass complications, could not be successfully treated with intravenous heparin and thus progressed on to complete IVC thrombosis. She developed phlegmasia cerulea dolens and required bilateral above-the-knee amputations. She subsequently died 3 months after her procedures. CONCLUSION: It appears that IVC filter placement at the time of OGB surgery is a relatively benign intervention with a maximal benefit. A note of caution should be exerted for those obese patients who have a hypercoagulable disorder and for those who have complications related to the gastric bypass. An aggressive posture, which may consist of immediate anticoagulation after their procedures (only when it is deemed safe), should be advocated in this small sub-group of morbid obese patients.

Experience with a modified composite sequential bypass technique for limb-threatening ischemia.

BACKGROUND: Composite sequential femoro-popliteal-distal bypass is a valuable option for treatment of critical limb ischemia when autogenous vein is limited and an isolated popliteal or distal arterial segment exists. We report a modified technique for composite sequential bypass and the results with its use over a 14-year period. METHODS: Twenty-five modified composite sequential bypass procedures were performed on 24 patients to treat gangrene, ischemic ulceration, and severe rest pain. Vein grafts were anastomosed from blind popliteal or blind distal arterial segments above-knee (7) or below-knee (18) to a distal outflow vessel including the below-knee popliteal (1), posterior tibial (5), anterior tibial (7), or peroneal (12) artery. Polytetrafluoroethylene bypass grafts were then placed from a suitable inflow artery to the proximal hood of the vein graft. RESULTS: Cumulative primary patency rates were 80% at 3 years, and 65% at 5 years. The limb-salvage rate was 85% at 4 years. Occlusion of the prosthetic segment with a patent distal vein segment was recognized in two patients who presented with less severe recurrent ischemia. Limb-salvage in these patients was achieved by a secondary prosthetic graft to the patent vein graft. CONCLUSION: Our modified configuration of the prosthetic-vein anastomosis for composite sequential bypass is an alternative to the conventional procedure and may help preserve vein graft patency should the polytetrafluoroethylene graft thrombose.

Endovascular management of multiple arteriovenous fistulae following failed laser-assisted pacemaker lead extraction.

A woman presented for evaluation of new-onset left arm edema after failed laser-assisted pacemaker lead extraction. Initial workup demonstrated a left subclavian artery to vein arteriovenous fistula (AVF). She underwent repair of the AVF with placement of a covered stent in the subclavian artery, however, her symptoms did not completely resolve. Investigation revealed a left common carotid artery to left innominate vein AVF, which was repaired by deploying a covered stent retrograde into the left common carotid artery. Her symptoms subsequently resolved. Multiple iatrogenic AVF can be repaired endovascularly, however, a high degree of suspicion for multiple injuries should be maintained.

Perimalleolar and pedal thromboembolectomy and bypasses to treat distal embolization during aortoiliac aneurysm repairs.

OBJECTIVES: Lower extremity embolization occurs during aortoiliac aneurysm repair and may require major amputation when distal arteries are occluded. Because nonoperative treatments are often ineffective, we evaluated an aggressive operative approach. METHODS: In the past 11 years, we performed 328 endovascular and 350 open aortoiliac aneurysm repairs. Excluding cases of embolization to iliac, femoral, popliteal, and more proximal tibial vessels, which were treated in a standard fashion, foot ischemia severe enough to produce cadaveric, pregangrenous, or gangrenous skin changes occurred from more distal embolization after seven endovascular and three open aortoiliac aneurysm repairs. Six of these 10 patients underwent thromboembolectomies of both their dorsalis pedis and perimalleolar posterior tibial arteries < or =4 hours of their original operation. In the other four patients, treatment was delayed 7 to 10 days. Because of progressive foot ischemia, arteriography was performed. From these results, four bypasses (3 autologous vein, 1 polytetrafluoroethylene graft) were performed to the transverse metatarsal arch, dorsalis pedis, perimalleolar peroneal artery, or perimalleolar anterior tibial artery. RESULTS: Patency and limb-salvage rates for both thromboembolectomy and bypass procedures were 100% at a mean follow-up of 3.0 years (range, 5 months-8 years). CONCLUSIONS: Perimalleolar and foot artery thromboembolectomy and bypasses to arteries as distal as the metatarsal arch can be effective treatment for distal embolization from aortoiliac aneurysm repair. Even when cadaveric, pregangrenous, or gangrenous lesions are present, distal arteriography and operative treatment (thromboembolectomy or bypass) may be indicated to successfully salvage the foot.

Experience with covered stents for the management of hemodialysis polytetrafluoroethylene graft seromas.

Prosthetic graft seromas is a rare complication that has been traditionally managed with open methods using partial graft replacement and open drainage. We report the first two cases of hemodialysis graft seromas successfully treated with a covered stent. Both patients underwent arteriovenous graft placement from the brachial artery to the axillary vein using a standard wall, tapered 4 to 7 mm polytetrafluoroethylene graft, but developed a seroma at the arterial end of the graft. Unsuccessful attempts were made to treat these seromas with percutaneous and open drainage. In both patients, an 8 mm x 50 mm Wallgraft (Boston Scientific, Natick, Mass) was retrogradely deployed "bareback" at the arterial end of the graft allowing for complete resolution of the graft seromas.

The incidence of pulmonary embolism in open versus laparoscopic gastric bypass.

Obesity independently increases the risk of pulmonary embolism (PE). We compare a superobese population (body mass index [BMI] > 55 kg/m(2)) undergoing open gastric bypasses (OGBs) with a similarly matched group of laparoscopic gastric bypasses (LGB) to see if the incidence of PE differs. We included all patients undergoing OGB (n = 193, average BMI = 51 kg/m(2)) at our institution by a single surgeon between July 1999 and April 2001. Thirty-one patients were superobese (BMI > 55 kg/m(2)). LGB was started at our institution in April 2001. Since that time 213 patients (average BMI = 52 kg/m(2)) have undergone the procedure. One hundred and nine patients were superobese. Pre- and postoperative prophylaxis included sequential compression stockings and subcutaneous heparin. Postoperatively, patients who developed signs of hypoxia, tachypnea, or tachycardia underwent a chest X-ray and spiral computed tomography. In addition, all patients who expired in the 30-day postoperative period underwent postmortem examination. Data were analyzed using the chi-squared test. In the OGB group, four patients (2.1%) developed PE. All occurred in superobese patients with a BMI > 55 kg/m(2). Three were fatal PEs and one was nonfatal. None of these patients had a prior history of deep vein thrombosis, PE, venous stasis disease, or pulmonary hypertension. In the LGB group, one patient (0.9%) had a nonfatal PE. This patient had a history of deep vein thrombosis. The incidence of PE was statistically higher in the superobese OGB group (P < 0.01). Despite the theoretical hindrance to venous return and vena caval compression observed with pneumoperitoneum, fewer PEs occurred in the laparoscopic group. Our data, however, suggest that patients with a BMI > 55 kg/m(2) might be at an increased risk for PE independent of operative approach.

Experience with inferior vena cava filter placement in patients undergoing open gastric bypass procedures.

OBJECTIVE: Patients undergoing open gastric bypass (OGB) for morbid obesity are at significant risk for pulmonary embolism (PE) despite the use of subcutaneous heparin injections and sequential compression devices. Prophylactic preoperative inferior vena cava (IVC) filter placement may reduce this risk. We report our experience with simultaneous IVC filter placement and OGB in an operating room setting. METHODS: From July 1999 to April 2001, 193 patients (group 1) underwent OGB. Eight patients had prophylactic intraoperative IVC filters placed for deep vein thrombosis, PE, or pulmonary hypertension. From May 2001 to January 2003, 181 patients (group 2) underwent OGB. There were 33 IVC filters placed for body mass index (BMI) greater than 55 kg/m2 in addition to the above-mentioned criteria. To confirm observations made in group 1 and 2 patients, from July 2003 to May 2005, 197 patients (group 3) underwent OGB, and patients with a BMI greater than 55 kg/m2 (n = 35) were offered IVC filter placement. Group 3A (n = 17) consented to IVC filter placement, and group 3B (n = 18) did not. RESULTS: Fifty-eight IVC filters were placed (100% technical success rate) with an increase in operating room time of 20 +/- 5 minutes. In group 1, the eight patients with IVC filters had a BMI greater than 55 kg/m2. There were four PEs (3 fatal and 1 nonfatal) in the other 185 patients, all which occurred in patients with BMIs greater than 55 kg/m2. In group 2, there were no PEs. The perioperative PE rate in these patients was reduced from 13% (4/31; 95% confidence interval [CI], 1.1%-25.7%) to 0% (0/33; 95% CI, 0%-8.7%). Perioperative mortality was reduced from 10% (3/31; 95% CI, 0%-20.0%) to 0% (0/33; 95% CI, 0%-8.7%). There were no pulmonary emboli or deaths related to PE in group 3A patients. Group 3B patients had a 28% PE rate (two fatal and three nonfatal) and an 11% PE-related death rate. None of the remaining patients in group 3 had a PE. CONCLUSIONS: Intraoperative IVC filter placement for the prevention of PE in morbidly obese patients undergoing OGB is feasible. We observed a significant reduction in the perioperative PE rate when a BMI greater than 55 kg/m2 was used as an indication for IVC filter placement despite the use of subcutaneous heparin injections and sequential compression devices.

Absence of proximal neck dilatation and graft migration after endovascular aneurysm repair with balloon-expandable stent-based endografts.

OBJECTIVE: Proximal neck dilatation (PND) and/or endograft migration with the subsequent development of type I endoleak is a significant cause of late endograft failure after endovascular abdominal aortic aneurysm repair (EVAR). Although there are numerous reports examining PND in patients receiving endografts that use self-expanding stents (SES) for proximal fixation, there are no such reports for patients treated with endografts that use balloon-expanding stents (BES). The purpose of this study was to investigate PND and endograft migration after EVAR with BES endografts. METHODS: We retrospectively reviewed all charts and all serial computed tomographic scans available for patients who underwent EVAR with a BES endograft (surgeon-made, aortounifemoral polytetrafluoroethylene graft with a proximal Palmaz stent) between August 1997 and October 2002. Only patients with longer than a 12-month follow-up were analyzed. Neck diameter was measured at the level of the lowest renal artery and at 5 mm below it. PND was defined as neck enlargement of 2.5 mm or more. To assess endograft migration, the distance between the superior mesenteric artery and the cranial end of the BES was measured. Stent migration was defined as a change of 5 mm or more. RESULTS: A total of 77 patients received this device during the study period. The technical success rate was 99%. The 1-, 3-, and 5-year survival was 66%, 48%, and 29.5%, respectively. Complete serial computed tomographic scans were available in 41 of the 48 patients who survived 12 months or longer after the operation. The mean follow-up period for these patients was 31 months (range, 12-66 months). The maximum aneurysm diameter was either unchanged or decreased in 35 patients (85%). The immediate postoperative proximal neck diameter was 19 to 29 mm (median, 24 mm). This was unchanged at the latest follow-up. None of the patients had significant PND. The cranial end of the BES was located in the area between 14 mm proximal and 36 mm distal to the superior mesenteric artery (median, 6 mm). None of the patients developed significant endograft migration. CONCLUSIONS: Neither PND nor endograft migration was observed with the BES endograft. The nature of the SES may be responsible for the observed neck dilatation and device migration after EVAR with SES endografts. This study suggests that BES may be a better fixation method for EVAR.

Palmar arch revascularization for arterial occlusion of the distal upper extremity.

During a period of nine years, 10 patients, ages 42 to 66 years (55 +/- 7, mean +/- SD) underwent upper extremity bypass for ischemic changes to the hand not responsive to conservative management. Patients were referred from the vascular department at the authors' institution. Preoperative angiograms were performed and attempts at angioplasty or intravenous attempts to dissolve clots were carried out (with tissue plasminogen activator-tPA) when appropriate. Patients with persistent upper extremity ischemia and an obvious occlusion with reconstitution in the hand were candidates for upper extremity bypass to the palmar arch. All patients had upper extremity bypasses performed with reverse saphenous vein grafts. The proximal anastomoses (end-to-side) were performed by either the vascular or plastic surgery team, while all distal anastomoses (end-to-side) were performed by plastic surgery team microscopic magnification to the deep or superficial palmar arch. Postoperative follow-up ranged from 3 months to 3 years. The bypass graft to the hand resulted in improved pain and resolution of tissue ischemia in all cases. Patients with preoperative ulcers were completely healed by 3 months. The results are in accordance with previous studies demonstrating that improved blood flow afforded by the procedure can improve the healing of recalcitrant ulcers and mitigate the symptoms of ischemic changes. In addition, end-to-side anastomosis to the palmar arch offers significant advantages, in that the continuity of the arch is maintained with all possible outflow vessels, and the problems associated with size discrepancy in the anastomosed vessels are eliminated.

Influence of type II endoleak volume on aneurysm wall pressure and distribution in an experimental model.

OBJECTIVE(S): We have previously shown that type II endoleak size is a predictor of aneurysm growth after aortic endografting. To better understand this observation, we investigated the influence of endoleak size on pressure transmitted to the aneurysm wall and its distribution within the aneurysm sac. METHODS: In an ex vivo model, an artificial aneurysm sac was incorporated within a mock circulation comprised of rubber tubing and a pulsatile pump. Three strain-gauge pressure transducers were placed in the aneurysm wall at different locations, including the site of maximum aneurysm diameter. The aneurysm was filled with either human aneurysm thrombus or dough that mimicked thrombus and simulated type II endoleaks of varying volumes (1 to 10 mL) were created. Aneurysm wall pressure (AWP) measurements were recorded at mean arterial pressures (MAPs) of 60, 80, and 100 mm Hg. Correlation coefficients ( r ) and analysis of variance were used to assess the relationship between endoleak volume and AWP. RESULTS: Increasing endoleak volume '3 cm 3 resulted in proportionally increased AWP at all levels of MAP and at all sites, with highest pressures recorded at the site of the maximum aneurysm diameter (r = 0.83 when MAP = 100 mm Hg; r = 0.85 when MAP = 80 mm Hg; r = 0.88 when MAP = 60 mm Hg; P < .001). AWP plateaued when the endoleak volume was >3 cm 3 . Pressure distribution within the sac was not uniform. Although the difference was within +/-10%, statistically significant higher AWPs were observed at the site of maximum aneurysm diameter (P <.001). AWP also correlated with MAP. CONCLUSIONS: Increasing type II endoleak volume results in proportionally higher AWP, which is greatest at the site of maximum aneurysm diameter. This study confirms the clinical observation that type II endoleak volume and MAP may be important predictors of aneurysm expansion. CLINICAL RELEVANCE: Our experimental model of a type II endoleak revealed that endoleak size is a significant factor that influences the magnitude of pressure transmission into the aneurysm wall. Increasing volume of the endoleak nidus was associated with proportionally higher aneurysm sac pressures. This mechanism may, in fact, account for the increased risk of aneurysm expansion observed in our clinical experience, thereby suggesting the need for more aggressive surveillance and possibly earlier intervention for patients with larger endoleaks.

Discontinuous, staccato growth of abdominal aortic aneurysms.

BACKGROUND: To evaluate whether abdominal aortic aneurysm (AAA) growth in individual patients can be characterized as continuous or discontinuous (staccato). STUDY DESIGN: From 1996 to 2002, 609 patients presented with unruptured AAAs. Of these, 278 underwent prompt repair and 331 were observed. In this study, we included 52 patients (16% of the latter group) who had at least four CT scans and were observed for 18 months or longer without any intervention. AAA growth was defined as any increase in diameter of >/= 3 mm over any observation period(s). AAA nongrowth was defined as absence of growth for at least 6 months. Staccato growth was defined as at least one period of nongrowth combined with at least one period of growth. RESULTS: The 52 patients had a mean age of 75 +/- 8 (SD) years. The mean observation period was 42 +/- 20 months and the mean AAA diameter growth rate was 3.6 +/- 2.4 mm/y. Only 12 of these 52 patients (23%) demonstrated continuous growth. Staccato growth occurred in 34 patients (65%). Six patients (12%) showed no growth at all over 18 to 57 months (mean 30 months). No correlation was observed between initial diameter of AAAs and a patient's individual growth rate during the whole observation period (R = 0.04, p = 0.46). CONCLUSIONS: Individual AAA behavior is usually characterized by periods of nongrowth alternating with periods of growth, ie, staccato growth. Some aneurysms may have long periods of nongrowth. Accordingly, management decisions cannot be based on the presumption that observed growth rates of AAAs can be extrapolated to predict future growth rates.

Fate of collateral vessels following subintimal angioplasty.

PURPOSE: To evaluate the fate of collateral vessels adjacent to and within the target lesion following subintimal angioplasty (SIA). METHODS: Pre and postprocedural angiograms were reviewed for 29 patients undergoing SIA of the lower extremity arteries over a 3-year period. The number of patent collateral vessels

Predicting aneurysm enlargement in patients with persistent type II endoleaks.

OBJECTIVE: The clinical significance of type II endoleaks is not well understood. Some evidence, however, indicates that some type II endoleaks might result in aneurysm enlargement and rupture. To identify factors that might contribute to aneurysm expansion, we analyzed the influence of several variables on aneurysm growth in patients with persistent type II endoleaks after endovascular aortic aneurysm repair (EVAR). METHODS: In a series of 348 EVARs performed during a 10-year period, 32 patients (9.2%) developed type II endoleaks that persisted for more than 6 months. Variables analyzed included those defined by the reporting standards for EVAR (SVS/AAVS) as well as other endoleak characteristics. Univariate, receiver operating characteristic curve, and Cox regression analyses were used to determine the association between variables and aneurysm enlargement. RESULTS: The median follow-up period was 26.5 months (range, 6-88 months). Thirteen patients (41%) had aneurysm enlargement by 5 mm or more (median increase in diameter, 10 mm), whereas 19 (59%) had stable or shrinking aneurysm diameter. Univariate and Cox regression analyses identified the maximum diameter of the endoleak cavity, ie, the size of the nidus as defined on contrast computed tomography scan, as a significant predictor for aneurysm enlargement (relative risk, 1.12; 95% confidence interval, 1.04-1.19; P =.001). The median size of the nidus was 23 mm (range, 13-40 mm) in patients with aneurysm enlargement and 8 mm (range, 5-25 mm) in those without expansion (Mann-Whitney U test, P <.001). Moreover, receiver operating characteristic curve and Cox regression analyses showed that a maximum nidus diameter greater than 15 mm was particularly associated with an increased risk of aneurysm enlargement (relative risk, 11.1; 95% confidence interval, 1.4-85.8; P =.02). Other risk factors including gender, smoking history, hypertension, need of anticoagulation, aneurysm diameter, type of endograft used, and number or type of collateral vessels were not significant predictors of aneurysm enlargement. CONCLUSIONS: In patients with persistent type II endoleaks after EVAR, the maximum diameter of the endoleak cavity or nidus is an important predictor of aneurysm growth and might indicate the need for more aggressive surveillance as well as earlier treatment.

Variability of maximal aortic aneurysm diameter measurements on CT scan: significance and methods to minimize.

OBJECTIVES: We noted substantial differences when measuring repeatedly the same abdominal aortic aneurysm (AAA) on the same computed tomography (CT) scan. This study quantitated this variability, and methods to minimize it were developed. METHODS: The CT maximal diameter of 25 AAAs was measured by eight experienced observers, including six vascular surgeons and two radiologists, using two methods: an unstandardized protocol, and a standardized protocol using fine calipers to carefully measure the largest diameter perpendicular to the estimated aneurysm centerline, from outer aneurysm wall to outer wall. The average measurement difference between observers was calculated for each method. The average difference between each observer's measurement and the official radiology report value was also calculated. Agreement between the two measurement methods was assessed with Bland-Altman plots. RESULTS: The difference in maximal diameter measurements between each observer averaged 4.0 +/- 5.1 mm (range, 0.0-35.0 mm) with the unstandardized method. The mean measurement difference with the standardized protocol was significantly lower, and averaged 2.8 +/- 4.4 mm (range, 0.0-26.0 mm; P<.05). Measurements taken from the official radiology report differed from each of the observer's standardized measurement by an average of 5.0 +/- 6.3 mm (range, 0.0-28.0 mm). This difference was similar for both the unstandardized and standardized methods. Bland-Altman plots confirmed the wide variation of the maximal diameter measurements when the unstandardized method was compared with the standardized method (95% confidence interval, -9-9 mm). CONCLUSIONS: Routine CT maximal diameter measurement of AAAs can have substantial interobserver variability. Standardized measurement protocols can decrease, but not eliminate, this measurement variability. Thus apparent size changes based on CT measurements may represent measurement artifact rather than actual aneurysm growth or shrinkage, particularly when a standardized system is not used.

System to decrease length of stay for vascular surgery.

OBJECTIVES: Reduction of length of stay (LOS) is critical for optimal use of hospital resources. We developed and evaluated a system to aggressively reduce LOS for vascular surgery. METHOD: Key to this system, which we introduced on January 1, 2001, was appointment of a LOS officer, who communicated daily during hospitalization with patients and families about discharge planning, organized outpatient services for wound care and rehabilitation to transition patients quickly to nonhospital care, and had biweekly meetings with relevant paramedical services. LOS for 509 patients operated on in 2000 (standard group) was compared with LOS for 474 operated on in 2001 and 595 patients operated on in 2002 (LOS reduction groups). Data for all patients with aortic aneurysm, carotid artery stenosis, lower extremity critical ischemia or amputation, and foot debridement were included. RESULTS: LOS in 2000 averaged 8.5 days, compared with 5.9 days in 2001 and 5.6 days in 2002. All decreases in LOS for each diagnostic category in 2001 and 2002 were statistically significant (P = <.001-.03). There was no significant increase in readmission rate (2.2% vs 1.9% and 2.0%, respectively), mortality rate (0.8% vs 0.6% and 0.7%, respectively), or percent of patients who received endovascular treatment (18% vs 16% and 14%, respectively). These decreases in LOS saved the hospital more than US dollars 616200 in 2001, and US dollars 847550 in 2002 (US dollars 500/patient-day). CONCLUSIONS: A committed LOS officer with major specific daily responsibilities for decreasing LOS and discharging patients resulted in a 31% to 33% decrease in LOS, with important cost savings to the hospital and no negative effect on patient care.

Is elevated creatinine level a contraindication to endovascular aneurysm repair?

PURPOSE: It is widely believed that chronic renal insufficiency (CRI) greatly increases the risk associated with endovascular abdominal aortic aneurysm repair (EVAR) and is a relative contraindication to the procedure and to the use of intra-arterial contrast agents (IACA). We reviewed a 5-year EVAR experience to determine whether the procedure and use of IACA have an important deleterious effect on renal function in patients with and without pre-existing CRI. METHODS: Endovascular aneurysm repair (EVAR) was performed in 200 patients with a variety of endografts, with intra-arterial contrast agents. The patients were retrospectively assigned to three groups on the basis of preoperative serum creatinine concentration (Cr): group 1 (n = 108), Cr less than 1.5 mg/dL (normal range); group 2 (n = 65), Cr 1.5 to 2.0 mg/dL; group 3 (n = 27), Cr 2.1 to 3.5 mg/dL. No patients had undergone hemodialysis. In groups 2 and 3, patients received hydration perioperatively, and received mannitol intraoperatively; no nephrotoxic drugs were administered during the procedure, other than nonionic contrast agent (Omnipaque 350). RESULTS: The incidence of postoperative complications between the three study groups was not statistically different. In group 1 a transient increase in serum Cr (>30% over baseline and >1.4 mg/dL) was noted in three patients (2.7%), two of whom (1.9%) required temporary hemodialysis and one (0.9%) who died of renal failure. In group 2 a transient increase in serum Cr was noted in two patients (3.1%); both patients (3.1%) required temporary hemodialysis, and one patient (1.5%) died of renal failure. In group 3 a transient increase in serum Cr was noted in two patients (7.4%); one patient (3.7%) required temporary hemodialysis, and one patient (3.7%) died of renal failure. Perioperative hypotension significantly increased the risk for elevated serum Cr and death (P <.05), and larger contrast volume was associated with an increase in serum Cr (P <.05) during the postoperative period. CONCLUSIONS: EVAR with intra-arterial contrast agents can be accomplished in patients with chronic renal insufficiency who do not require dialysis, with limited and acceptable morbidity and mortality, similar to that observed with open aneurysm repair. Contrary to other reports in which perioperative precautions were not used, our study shows that with EVAR the risk for worsening renal failure, dialysis, and death is only slightly, and not significantly, greater in patients with preoperative chronic renal insufficiency compared with patients with normal renal function. Perioperative hypotension and increased contrast volume are significant risk factors for postoperative increase in serum Cr and death. With appropriate precautions such as averting perioperative hypotension and limiting the volume of nonionic contrast agents, elevated Cr need not be a contraindication to EVAR with intra-arterial contrast agents.