Predictors and Outcomes of Nondiagnostic Ultrasound for Acute Appendicitis in Children.

Ultrasound assessments of children with possible acute appendicitis (AA) are often nondiagnostic. We aimed to identify the predictors of nondiagnostic ultrasound and to investigate the outcomes. A retrospective review was conducted on children aged 4 to 17 years evaluated in 2013 for AA with ultrasound at a tertiary hospital pediatric emergency department. Demographics, clinical data, and outcomes were analyzed. Of 528 children, 194 (36.7%) had diagnostic ultrasounds and 334 (63.3%) had nondiagnostic ultrasounds. Nondiagnostic ultrasounds were more common after-hours (7 pm-7 am weekdays and on weekends, 70.7%) than during business hours (7 am-7 pm weekdays; 29.3%). After-hours timing and female sex were identified as independent predictors of nondiagnostic ultrasounds (P < 0.05 for both). AA was diagnosed in 35 children with a nondiagnostic ultrasound (10.5%; P < 0.05). No child who underwent a nondiagnostic ultrasound was found to have AA with laboratory values of white blood cell < 11 × 103/µL and c-reactive protein (CRP) < 5 mg/dL. Children with nondiagnostic ultrasounds have a low likelihood of AA if white blood cell < 11 and CRP < 5. We propose a management algorithm that we hope will help reduce admissions and decrease the use of computed tomography scans.

Vancomycin intermittent dosing versus continuous infusion for treatment of ventilator-associated pneumonia in trauma patients.

Current guidelines for the empiric treatment of ventilator-associated pneumonia (VAP) recommend that vancomycin is dosed 15 mg/kg and administered twice daily for a target trough level of 15 to 20 µg/mL. This study compared conventional intermittent vancomycin infusion (IVI) with continuous vancomycin infusion (CVI). Our prospective, randomized study compared CVI with IVI in trauma patients with suspected VAP. The primary outcome measure was a serum vancomycin level within the target level 48 hours after initiation of therapy. Treatment groups were compared using standard statistical methods. The study included 73 patients, 36 IVI and 37 CVI. Eighteen patients were withdrawn from the study as a result of discontinuation of the drug before 48 hours or failure to draw levels at the appropriate time, resulting in 27 IVI and 28 CVI study patients. There were no differences between treatment groups in gender (P = 0.97), Injury Severity Score (P = 0.70), total body weight (P = 0.36), or age (P = 0.81). The mean serum vancomycin level for the IVI group was 8.9 ± 3.9 µg/mL, and the CVI level was 19.8 ± 6.13 µg/mL (P < 0.0001). Two patients in the IVI group (7.4%) were in the therapeutic range compared with 16 (57.1%) in the CVI group (P < 0.0001). Six patients in the CVI group (21.4%) and none of the IVI patients had supratherapeutic levels. Four patients developed renal insufficiency, three IVI (11.1%) and one CVI (3.6%) (P = 0.36). The current American Trauma Society dosing recommendations for vancomycin for presumptive VAP treatment are inadequate. Continuous vancomycin infusion should be adopted as the standard dosing strategy.

MOPEDS: Motorized Objects Propelling Ethanol Drinking Subjects.

Mopeds are not subject to the same laws and jurisdiction as cars or motorcycles, including the requirement of a driver's license. We undertook this study to examine the influence of alcohol (ETOH) on moped crashes. We retrospectively reviewed adult moped injuries compared with motor vehicle crashes (MVCs) and motorcycle crashes (MCCs) from 1995 through 2006. Demographics, severity of injury, mortality, and serum ETOH levels were recorded. Data were analyzed using the Student t test for continuous data and the χ² test for proportional data. Motor vehicle crashes accounted for 7186 admissions. MCC and moped crashes numbered 973 and 113, respectively. Although not statistically significant (P = 0.064), moped crashes yielded the highest mortality (9.7%) compared with MCCs (8.5%) and MVCs (6.7%). An increased association of blood ETOH levels with moped crashes, however, was statistically significant (P = 0.004). Serum ETOH levels above 0.05 g/dL were observed in 1681 MVCs (23.4%), 241 MCCs (24.8%), and 44 moped crashes (39%). In this study, we discovered that moped crashes demonstrate a significantly higher ETOH involvement than either MVCs or MCCs representing a previously unrecognized public safety risk.

An evaluation of electrosurgical vessel-sealing devices in biliary tract surgery in a porcine model.

OBJECTIVES: The purpose of this study was to evaluate two electrosurgical vessel-sealing devices in biliary surgery. METHODS: Porcine common bile ducts (CBDs) were sealed with two electrosurgical devices, an electrothermal bipolar vessel-sealing device (EBVS) and ultrasonic coagulation shears. Acute study animals underwent surgical bile duct sealing followed by immediate burst pressure testing. Chronic study animals were maintained for 1 week postoperatively and then tested. RESULTS: The seal failure rate in the acute study was 50% for both the EBVS device and shears, and 0% for the laparoscopic surgical clip device used as a control. The latter had significantly higher burst pressures (646.2 ± 281.8 mmHg; P = 0.006) than the EBVS device (97.6 ± 86.6 mmHg) and shears (71.7 ± 89.3 mmHg). No significant difference in burst pressures was noted between the EBVS device and shears (97.6 ± 86.6 mmHg vs. 71.7 ± 89.3 mmHg). In the chronic study, obvious bile leaks occurred in one of four pigs (25%) in the EBVS device subgroup and two of four pigs (50%) in the shears subgroup. The average proximal CBD pressure in seven pigs was 16.1 ± 4.1 mmHg. The average chronic burst pressure in the control subgroup was 1088.0 ± 922.6 mmHg. CONCLUSIONS: Given the high rates of failure of the EBVS device and the shears in consistently sealing biliary ducts, we do not recommend their routine use in biliary surgery.

Resident work hour restrictions impact chief resident operative experience.

Since the institution of the Accreditation Council for Graduate Medical Education resident work restrictions, much discussion has arisen regarding the potential effect on surgical resident training. We undertook this study to examine the effects on resident operative experience. We retrospectively analyzed chief residents' Accreditation Council for Graduate Medical Education case logs before (PRE) and after (POST) the 80-hour work restriction. Overall, 22 resident logs were evaluated, six PRE and 16 POST. Four case categories were examined: total major cases, total trauma operative cases, total chief cases, and total teaching assistant cases. Significance was defined as P < 0.05. Comparing the PRE and POST groups demonstrated a trend toward fewer total major cases (1061 vs 964, P = 0.38) and fewer total trauma operative cases (55 vs 47, P = 0.37). Teaching assistant cases increased from 67 to 91 but also failed to reach significance (P = 0.37). However, further comparison between the PRE and POST groups yielded a statistically significant decrease in the number of total chief cases (494 vs 333, P = 0.0092). The significant decrease in the number of total chief cases demonstrates that the work hour restriction most affected the chief year operative experience. Further evaluation of resident participation in nonoperative facets may reveal additional deficiencies of surgical training under work hour restrictions.

Removal of erythropoietin from anaemia trauma practice guideline does not increase red blood cell transfusions and decreases hospital utilization costs.

INTRODUCTION: We previously demonstrated that utilization of erythropoietin (r-EPO) did not significantly reduce blood utilization in trauma patients. We undertook this study to analyze blood utilization 1 year after r-EPO removal from our trauma service anaemia practice management guideline. METHODS: Electronic records of patients admitted to the trauma service were retrospectively reviewed for units of packed red blood cells (pRBCs) transfused and for units of r-EPO administered 12 months before the initiation of an anaemia practice guideline (PRE), 12 months during the use of an anaemia guideline (GUIDE), and 12 months following removal of r-EPO from the guideline (POST). Hospital acquisition cost was also reviewed for the respective time periods. Nominal data were analyzed using chi-squared or Fisher's exact tests, and interval data were compared using ANOVA followed by Tukey's test where appropriate. Results were considered significant for P<0.05. RESULTS: Over the 3-year study period, 4881 patients were admitted to the trauma service and included in this study. The hospital length of stay, intensive care unit length of stay, and units of pRBC transfused were similar among all three groups. Group I (PRE) received a total of 228 doses of r-EPO at a cost of $102,600. Group II (GUIDE) received a total of 410 doses at a cost of $184,500. Group III (POST) received 28 doses of r-EPO at a cost of $12,600. CONCLUSION: Removal of erythropoietin from our trauma service anaemia practice management guideline did not result in increased blood utilization. However, it yielded a hospital acquisition cost savings of $171,900.

A comparison of gastrojejunal anastomoses with or without buttressing in a porcine model.

INTRODUCTION: The addition of staple-line reinforcements on circular anastomoses has not been well studied. We histologically and mechanically analyzed circular- stapled anastomoses with and without bioabsorbable staple-line reinforcement (SeamGuard, W. L. Gore & Associates, Flagstaff, AZ) in a porcine model. METHODS: Gastrojejunal anastomoses were constructed using a #25 EEA Proximate ILS (Ethicon Endo-Surgery, Cincinnati, OH) mechanical stapling device with and without Bioabsorbable SeamGuard (BSG). Gastrojejunal anastomoses were resected acutely and at 1 week, and burst-pressure testing and histological analysis were performed. Standardized grading systems for inflammation, collagen deposition, vascularity, and serosal inflammation were used to compare the two anastomosis types. RESULTS: Acute burst pressures were significantly higher with BSG than with staples alone (1.37 versus 0.39 psi, p=0.0075). Burst pressures at 1 week were significantly lower with BSG than with staples alone (2.24 versus 3.86 psi, p=0.0353); however, both readings were above normal physiologic intestinal pressures. There was no statistical difference in inflammation (13.4 versus 15.6, p=0.073), width of mucosa (3.2 mm versus 3.2 mm, p=0.974), adhesion formation (0 versus 0.5, p=0.575), number of blood vessels (0.5 versus 1.0, p=0.056), or serosal inflammation (2.0 versus 1.0, p=0.27) between the stapled anastomoses and those buttressed with BSG. Stapled-only anastomoses had statistically more collagen (2.0 versus 1.0, p=0.005) than the anastomoses supported with BSG. CONCLUSIONS: The addition of BSG as a staple-line reinforcement acutely improves the burst strength of a circular anastomosis but not at 1 week. At 1 week, a decrease in collagen content with the BSG-buttressed stapled anastomosis was the only difference in the histologic parameters studied with no difference in vascularity, adhesions, or inflammation. The long-term effect of BSG on anastomotic strength or scarring is yet to be determined. The clinical implications may include decreased stricture formation and also decreased strength at anastomoses.

Comparison of blood vessel sealing among new electrosurgical and ultrasonic devices.

BACKGROUND: Bipolar electrosurgical devices and ultrasonic devices are routinely used in open and advanced laparoscopic surgery for hemostasis. New electrosurgical and ultrasonic instruments demonstrate improved quality and efficiency in blood vessel sealing. METHODS: The 5-mm laparoscopic Gyrus PKS Cutting Forceps (PK), Gyrus Plasma Trissector (GP), Harmonic Scalpel (HS), EnSeal Tissue Sealing and Hemostasis System (RX), LigaSure V with LigaSure Vessel Sealing Generator (LS), LigaSure V with Force Triad Generator (FT), and Ligamax 5 Endoscopic Multiple Clip Applier (LM) were tested to compare burst pressure, sealing time, and failure rate. Each device was used to seal 13 small (2-3 mm diameter), 13 medium (4-5 mm diameter), and 13 large (6-7 mm diameter) arteries from euthanized pigs. A p value <0.05 was considered statistically significant. RESULTS: Mean burst pressures were not statistically different for 2-3 mm or 6-7 mm vessels. For 4-5 mm vessels, LS had the highest mean burst pressure recorded. Mean seal times were shorter for every vessel size when FT was compared with LS (p < 0.05). The shortest sealing times for 2-3 mm vessels were recorded for GP. The shortest sealing times for medium and large vessels were observed with FT. The highest percentage failure rate for each vessel size occurred with GP. For 4-5 mm diameter vessels, the failure rate was 48% for GP, 41% for PK, and 22% for HS. For 6-7 mm diameter vessels, the failure rate was 92% for GP, 41% for PK, and 8% for HS. LM and FT had no recorded failures. CONCLUSION: Among the new 5-mm laparoscopic electrosurgical and ultrasonic instruments available for testing, RX, LS, and FT produced the highest mean burst pressures. FT had the shortest mean seal times for medium and large vessels. Minimal or no seal failures occurred with HS, RX, LS, LM, and FT.

Guidelines for power and time variables for microwave ablation in an in vivo porcine kidney.

PURPOSE: Microwave technology provides an emerging thermal ablation technique for solid organ tumors. We propose guidelines and recommend optimal time and power for use. METHODS: Microwave ablations using a VivaWave Microwave Ablation System (Valleylab, Boulder, CO) were performed in vivo in a porcine kidney model. The independent variables were power (20, 30, 40, 45, 50, 60 W) and time (2, 4, 6, 8, 10, 15, 20 min) with the outcome variable diameter of ablation. Following ablations, kidneys were procured for gross and histological evaluation. Analysis of variance (ANOVA) was used followed by Tukey tests when appropriate. A P value of <0.05 was considered statistically significant. RESULTS: In 308 total ablations, a minimum of 7 ablations were performed in 35 of 42 power and time variables (83%). The outcome variable, ablation diameter, was affected significantly by time, power, and time/power interaction (P < 0.0001). For each time point, a one-way ANOVA showed an overall significant difference in ablation size X wattage (P < 0.0001). Tukey tests showed that, at each time point, ablation sizes at 45, 50, and 60 W were not significantly different. After determining that 45 W was optimal, a one-way ANOVA showed an overall significant difference in ablation sizes for time points at 45 W (P < 0.0001). Tukey tests showed that, at 45 W, ablation sizes at 10 min were significantly larger than ablation sizes at 8, 6, 4, and 2 min. CONCLUSIONS: We propose guidelines for use of a novel microwave ablation system and recommend use at 45 W for 10 min.

The effect of preoperative corticosteroids on peritoneal macrophage function after laparoscopic and open abdominal surgery in a rat model.

BACKGROUND: Peritoneal macrophages play an important role in the immune response after abdominal operations. The stress response after these operations has been associated with impaired phagocytosis by peritoneal macrophages. This study examined the influence of minimally invasive techniques and preoperative corticosteroid administration on postoperative peritoneal macrophage phagocytic activity. METHODS: After IACUC approval, 66 Sprague Dawley rats were randomly divided into 7 groups: baseline animals (B), anesthesia controls (AC), open cecectomy (OC), and laparoscopic cecectomy (LC). Within the AC, OC, and LC groups, half received intraperitoneal (IP) dexamethasone (10 mg/kg) 1 hour before surgery (+S), and the other half received an equal volume of normal saline IP (-S). Animals were observed postoperatively for 24 hours and were then euthanized. Peritoneal macrophages were harvested via intraperitoneal lavage. A phagocytosis assay was performed to calculate the net phagocytosis and percent response to the effector agent. Statistical analysis was performed using analysis of variance and a Student t test between groups. A P value of <.05 was considered significant. RESULTS: Significant differences were observed between groups. The B group had a response rate of 94.2% +/- 56.7%, which was not different from the AC groups (-S, P = .28; +S, P = .16) or the LC-S group (P = .9). The lowest phagocytic activity rate was in the OC-S group with a response rate of 33.8% +/- 28.5%. The highest phagocytic response rates occurred in the AC +S (145.2% +/- 60.2%) and LC +S (198.1% +/- 103.5%). These were not significantly different from each other (P = .3). The LC +S group had a significantly higher percent response than all of the other groups. The phagocytic response rate of the OC +S group was not different from either the AC-S group (P = .07) or the LC-S group (P = .8); however, it was less than the AC +S group (P = .02) and the LC +S group (P = .003). CONCLUSION: Open cecectomy resulted in greater impairment of the phagocytic activity of peritoneal macrophages than laparoscopic cecectomy. The addition of preoperative corticosteroids improved phagocytic activity back to baseline function. The combination of minimally invasive surgical technique and preoperative corticosteroid administration resulted in the greatest postoperative phagocytic function of peritoneal macrophages in a rat model.

Vena cava filter retrieval in therapeutically anticoagulated patients.

BACKGROUND: Vena cava filters (VCFs) are indicated in patients with active venous thromboembolism and are a contraindication to therapeutic anticoagulation. When patients can be anticoagulated, VCFs can be removed; however, patients often have anticoagulation discontinued during the retrieval procedure, leaving them at risk for pulmonary embolism (PE). The authors evaluated their experience with retrieving VCFs in therapeutically anticoagulated patients. METHODS: Data from a prospectively collected database of patients with VCFs placed between January 2005 and September 2007 were reviewed. The retrievals in therapeutically anticoagulated patients (international normalized ratio, 2.0-3.4) were performed using a strict protocol, including preretrieval and postretrieval cavograms. All retrievals were performed in the operating room, and patients were discharged home the same day and examined within 7 to 14 days. Descriptive statistics including means and counts were calculated. RESULTS: One hundred thirteen VCF removals occurred during the study period; 62 were attempted on anticoagulated patients (42 male and 20 female patients; mean age, 36.5 years). Thirty-five patients (56%) had VCFs placed for prophylaxis, 22 (35%) had deep venous thromboses or PEs but had contraindications to anticoagulation, and 5 (8%) were on anticoagulation, which was discontinued perioperatively for major surgical operations. The mean time the filters were in place was 153.7 days (range, 22-684 days). No extravasation was seen on postretrieval cavography. Eight of 62 removal attempts in anticoagulated patients were unsuccessful. One patient had a postoperative pneumothorax that was successfully managed without intervention. There were no operative bleeding complications, and no hematomas or contusions were seen at follow-up. CONCLUSIONS: The retrieval of VCFs in therapeutically anticoagulated patients can be performed without complication. Given the perioperative risk for PE, anticoagulation should not be discontinued for VCF retrieval.

Evaluation of selective treatment of penetrating abdominal trauma.

OBJECTIVE: In penetrating abdominal trauma, diagnostic imaging and the application of selective clinical management may avoid negative celiotomy and improve outcome. DESIGN: We prospectively observed patients with penetrating abdominal trauma over 15 months and recorded demographics, presentation, imaging, surgical procedure, and outcome. Patients who underwent immediate laparotomy were compared with patients who were observed and/or had a computed tomography (CT) scan. Outcomes of negative versus positive and immediate versus delayed celiotomy were compared. Chi-square and Student t tests were used. A p value of less than 0.05 was considered significant. SETTING: A level 1 trauma center. PARTICIPANTS: Adult patients who presented with penetrating abdominal injury. RESULTS: In all, 100 consecutive patients (mean age, 32 years) were included (male:female, 91:9; gunshot wound:stab wound, 65:35). Overall, 60 immediate and 10 delayed laparotomies were performed; 30 patients did not undergo surgery. Predictors of immediate celiotomy were hypotension (p = 0.03), anteriorly located entrance wounds (p = 0.0005), and transaxial wounds (p = 0.03). Overall morbidity and mortality was 32% and 2%, respectively. The negative celiotomy rate was 25%. Patients with a positive celiotomy had higher morbidity (p = 0.006) and longer hospital length of stay (p = 0.003) compared with negative celiotomy. A CT scan was employed in 32% of patients, with 100% sensitivity and 94% specificity. Delayed celiotomy (10%) did not adversely impact morbidity (p = 0.70) and was 100% therapeutic, with no deaths. CONCLUSION: Nonselective immediate celiotomy for penetrating abdominal trauma results in a high rate of unnecessary surgery. Hemodynamically stable patients can safely be observed and/or have contrast CT scans and undergo delayed celiotomy, if indicated. This selective treatment had no adverse effect on patient outcomes and can potentially improve overall outcome.

Comparing quality-of-life outcomes in symptomatic patients undergoing laparoscopic or open ventral hernia repair.

BACKGROUND: The aim of this study was to compare quality-of-life outcomes in patients with symptomatic hernias who were undergoing laparoscopic and open repairs. MATERIALS AND METHODS: Clinical data for patients undergoing ventral hernia repair were reviewed with quality-of-life surveys administered before and at least 6 months following surgery. RESULTS: The study included 56 symptomatic patients. Forty-one patients (73%) underwent laparoscopic repair, and 15 patients (27%) underwent open repair. There was no difference in preoperative quality-of-life scores on the SF-36 Health Survey between patients having laparoscopic or open repairs. Postoperative quality-of-life scores on the SF-36 survey were significantly improved in the laparoscopic group, compared with the open group, in general health (46% vs. 37%; P=0.0217), vitality (53% vs. 45%; P=0.0491), role-emotional (45% vs. 35%; P=0.0480), and mental health (49% vs. 39%; P=0.0381). Postoperative quality-of-life scores on the Carolinas Comfort Scale (CCS) were significantly improved in the laparoscopic group, compared with the open group, in bending over (3.15 vs. 5.87, P=0.0158), sitting up (2.51 vs. 5.13; P=0.0211), activities of daily living (2.48 vs. 5.75; P=0.0139), coughing or deep breathing (2.95 vs. 5.75; P=0.0314), walking (2.36 vs. 4.62; P=0.0427), exercising (3.19 vs. 6.14; P=0.0222), and total comfort scale (17.62 vs. 40.23; P=0.0084). CONCLUSIONS: Laparoscopic ventral hernia repair provides improved quality-of-life, compared with open repair, 6 months postoperatively. Nearly all physical variables measured by the CCS were significantly better when ventral hernias were repaired laparoscopically.

Imaging of the vena cava in the intensive care unit prior to vena cava filter insertion: carbon dioxide as an alternative to iodinated contrast.

This study evaluates the safety and effectiveness of carbon dioxide (CO2) as a contrast agent in patients in the intensive care unit undergoing vena cava filter (VCF) insertion. We prospectively evaluated patients in the intensive care unit undergoing bedside VCF insertion using CO2 cavagraphy. Blood pressure, pulse rate, mixed venous oxygen saturation, and intracranial pressure were monitored before, during, and after the CO2 injection. Fifty patients in the intensive care unit (mean age 48.2 +/- 16.5 years) were included in the study. Five patients had decreases in blood pressure, which resolved without intervention. Two patients required iodinated contrast as a result of inadequate CO2 imaging. All patients had successful insertion of VCF. The use of CO2 as a contrast agent is a safe and highly effective alternative for vena cava imaging and can be considered the first-line contrast agent for all critically ill patients requiring VCF placement.

A comparison of central venous and arterial base deficit as a predictor of survival in acute trauma.

BACKGROUND: The arterial base deficit has been demonstrated to be a marker of shock and predictive of survival in injured patients. The venous blood, however, may better reflect tissue perfusion. Its usefulness in trauma is unknown. We compared central venous with arterial blood gas analysis to determine which was a better predictor of survival in injured patients. METHODS: A prospective, nonrandomized series of acutely injured patients was investigated. Patients who had an arterial blood gas analysis for acid-base determination had a simultaneous central venous blood gas analysis and routine blood tests. Patient demographics, Injury Severity Score, and survival past 24 hours were recorded. Arterial and venous blood samples were analyzed for pH, PCO2, PO2, HCO3, hemoglobin-oxygen saturation, base deficit, and lactate. RESULTS: One hundred patients were enrolled. There were 76 survivors and 24 nonsurvivors. Wilcoxon rank sum test and multivariate logistic regression were used for each recorded variable; only central venous base deficit was predictive of survival past 24 hours (P = .0081). Specifically, arterial base deficit was not predictive of survival past 24 hours. CONCLUSION: In a prospective series of acutely injured patients, central venous base deficit, not arterial base deficit, was predictive of survival past 24 hours.

Factors affecting length of stay following colonic resection.

INTRODUCTION: In-hospital length of stay (LOS) has become a valuable measure of outcomes following any operation, which also directly impacts cost. The aim of this study was to identify the factors that affect LOS after colonic resection. MATERIALS AND METHODS: A retrospective analysis was performed of adult patients who underwent colonic resection over an 8-y period at a tertiary institution. Data collected included demographics, American Society of Anesthesiologists (ASA) score, preoperative comorbidities and medications, operative management, postoperative morbidity and mortality, and LOS. Statistical analysis included descriptive statistics and multiple logistic regression to identify variables predictive of prolonged LOS. RESULTS AND DISCUSSION: A total of 899 consecutive patients were identified. One hundred eighty-seven resections were performed urgently, and 712 were elective. Two-hundred forty-five cases were performed laparoscopically. Complications occurred in 205 cases (23%), and there were 32 deaths (4%). The median LOS was 7 d. Logistic analysis showed 15 variables to be predictive of prolonged LOS. These included advanced age, warfarin sodium use, ASA score >or=3, alcoholism, chronic obstructive pulmonary disease, end-stage renal disease, illicit drug use, total colectomy (versus segmental), open resections (versus laparoscopic), and postoperative complications. In addition, the presence of at least one postoperative complication was predictive of prolonged LOS (P = 0.0002, OR 2.4 95% CI 1.5-3.8). CONCLUSIONS: ASA score and the incidence of postoperative complications are the only significant categories of variables that predict prolonged LOS after colectomy. Laparoscopic approach and the extent of the resection are predictive as well.

Guidelines for power and time variables for microwave ablation in a porcine liver.

The purpose of our study was to provide guidelines for the use of a novel microwave ablation system. Microwave ablations using a 915-MHz system were evaluated in a porcine liver. The independent variables were power and time, with the outcome variable being diameter of ablation. After ablations, livers were procured for measurement and histologic evaluation. Our study consisted of 420 ablations. The outcome variable, ablation diameter, was affected significantly by time, power, and time/power interaction (p<0.0001). For each time point, a one-way analysis of variance (ANOVA) showed an overall significant difference in ablation size X wattage (p<0.0001). Tukey tests at each time point showed ablation sizes at 45, 50, and 60 W were not significantly different. After it was determined that 45 W was optimal, a one-way ANOVA showed an overall significant difference in ablation sizes for time points at 45 W (p<0.0001). Tukey tests revealed that at 45 W, ablation sizes at 10, 15, and 20 min were not statistically different. We propose guidelines for diameters based on different time and power variables and recommend 45 W for 10 min to achieve optimal diameters at the shortest time and lowest wattage.

Postoperative pulmonary embolism: timing, diagnosis, treatment, and outcomes.

BACKGROUND: Postoperative pulmonary embolism (PE) remains a major health concern. The purpose of our study was to evaluate our experience with postoperative PE. METHODS: We retrospectively reviewed the medical records of patients who had a postoperative PE at our institution. RESULTS: Our study included 115 patients. Prophylaxis was administered preoperatively in 31% of patients and postoperatively in 56% of patients. The diagnosis was obtained by computed tomography scan in 74 patients (64%), ventilation-perfusion scan in 24 patients (21%), angiogram in 8 patients (7%), and other modalities in 9 patients (8%). The time elapsed between surgery and the diagnosis of PE varied significantly by patient age (<40 y: 3 d, compared with 40-60 y: 11 d; P = .02). The majority of patients with PE were treated with anticoagulation (83%). Morbidity and mortality rates both were 9%. CONCLUSIONS: Age has a significant impact on the timing of postoperative PE, with the majority of cases being diagnosed with a computed tomography scan, and treated with anticoagulation.

Improved outcomes for laparoscopic appendectomy compared with open appendectomy in the pediatric population.

INTRODUCTION: The appendectomy is a common emergent surgical procedure in the pediatric population. The aim of this study was to examine our institution's experience and outcomes in the appendectomy in the pediatric population early in our transition from open surgery to a predominantly laparoscopic approach. METHODS: We retrospectively studied all pediatric patients (age 20 years) that underwent an appendectomy at a tertiary care center over 2 years. The data collected included patient demographics, comorbidities, operative details, outcomes, and complications. RESULTS: Two hundred twenty-three consecutive patients, with a mean age of 9.5 (3.9) years, were included in the study. Forty-four laparoscopic and 179 open appendectomies were performed. Two of the laparoscopic cases were converted to open appendectomies. Significant differences were seen between the two groups, with longer operative times (P < 0.0001) and lower estimated blood loss (P = 0.007) in the laparoscopic group. Operative times improved significantly for the laparoscopic group as the surgeons became more experienced (P = 0.03). The laparoscopic group used intravenous pain medication for a shorter time (0.8 vs. 1.9 days; P = 0.0003) and had a shorter postoperative hospital length of stay (2.2 vs. 3.4 days; P = 0.004). The laparoscopic group had fewer wound infections (2.3% vs. 6.2%; P = 0.3), intra-abdominal abscesses (4.5% vs. 5.6%; P = 0.8), and postoperative ileus (0% vs. 2.2%; P = 0.3), although these differences did not reach statistical significance. CONCLUSION: The laparoscopic appendectomy procedure is a safe alternative to open appendectomy in pediatric patients and results in shorter hospital stays with less postoperative pain.

Reversal of Hartmann's procedure: a high-risk operation?

BACKGROUND: Patients who undergo Hartmann's procedure often do not have their colostomy closed based on the perceived risk of the operation. This study evaluated the outcome of reversal of Hartmann's procedure based on preoperative risk factors. METHODS: We retrospectively reviewed adult patients who underwent reversal of Hartmann's procedure at our tertiary referral institution. Patient outcomes were compared based on identified risk factors (age >60 years, American Society of Anesthesiologists [ASA] score >2, and >2 preoperative comorbidities). RESULTS: One-hundred thirteen patients were included. Forty-four patients (39%) had an ASA score of >or=3. The mean hospital duration of stay was 6.8 days. There were 28 (25%) postoperative complications and no mortality. Patients >60 years old had significantly longer LOS compared with the rest of the group (P = .02). There were no differences in outcomes between groups based on ASA score or the presence of multiple preoperative comorbidities. An albumin level of <3.5 was the only significant predictor of postoperative complications (P = .04). CONCLUSIONS: The reversal of Hartmann's operation appears to be a safe operation with acceptable morbidity rates and can be considered in patients, including those with significant operative risk factors.