Novel simulation for training trauma surgeons.

BACKGROUND: Clinical training in operative technique is important to boost self-confidence in residents in all surgical fields but particularly in trauma surgery. The fully trained trauma surgeon must be able to provide operative intervention for any injury encountered in practice. In this report, we describe a novel training model using a human cadaver in which circulation in the major vessels can be simulated to mimic traumatic injuries seen in clinical practice. METHODS: Fourteen human cadavers were used for simulating various life-threatening traumatic injuries. The carotid and femoral arteries and the jugular and femoral vein were cannulated and connected to perfusate reservoirs. The arterial reservoir was connected to an intra-aortic balloon pump, which adds pulsatile flow through the heart and major arteries. Fully trained trauma surgeons evaluated the utility of this model for repairing various injuries in the thoracic and abdominal cavity involving the heart, lungs, liver, and major vessels while maintaining emergent airway control. RESULTS: Surgeons reported that this perfused cadaver model allowed simulation of the critical challenges faced during operative trauma while familiarizing the student with the operative techniques and skills necessary to gain access and control of hemorrhage associated with major vascular injuries. CONCLUSION: In this report, we describe a novel training model that simulates the life-threatening injuries that confront trauma surgeons. An alternative to living laboratory animals, this inexpensive and readily available model offers good educational value for the acquisition and refinement of surgical skills that are specific to trauma surgery.

Accelerated growth of bariatric surgery with the introduction of minimally invasive surgery.

HYPOTHESIS: An increase in national utilization of bariatric surgery correlates with the dissemination of laparoscopic bariatric surgery. DESIGN: Evaluation of Nationwide Inpatient Sample data from 1998 through 2002. SETTING: National database. PATIENTS: A total of 188,599 patients underwent bariatric surgery for the treatment of morbid obesity. MAIN OUTCOME MEASURES: Annual total number of bariatric operations, the proportion of Roux-en-Y gastric bypass vs gastroplasty, the proportion of laparoscopic cases, postoperative length of stay, crude in-hospital mortality, and the number of institutions that perform bariatric surgery. RESULTS: Between 1998 and 2002, the number of bariatric operations increased from 12,775 cases to 70,256 cases. The rate of bariatric surgery increased from 6.3 to 32.7 procedures per 100,000 adults. Laparoscopic bariatric surgery increased from 2.1% to 17.9%. The number of bariatric surgeons with membership in the American Society for Bariatric Surgery increased from 258 to 631, and the number of institutions that perform bariatric surgery increased from 131 to 323. During this 5-year period, the annual rate of laparoscopic bariatric surgery increased exponentially (by 44-fold) compared with a linear growth in open bariatric surgery (by 3-fold). CONCLUSIONS: Between 1998 and 2002, there was a 450% increase in the number of bariatric operations performed in the United States, a 144% increase in the number of American Society for Bariatric Surgery bariatric surgeons, and a 146% increase in the number of bariatric centers. The growth of laparoscopic bariatric surgery during this 5-year period greatly exceeds that of open bariatric surgery.

Comparative evaluation of tigecycline and vancomycin, with and without rifampicin, in the treatment of methicillin-resistant Staphylococcus aureus experimental osteomyelitis in a rabbit model.

OBJECTIVES: Staphylococcus aureus is the most common organism isolated in osteomyelitis. Methicillin-resistant S. aureus (MRSA) infections are particularly difficult to treat. We evaluated the efficacy of tigecycline and vancomycin with and without rifampicin in a rabbit model of MRSA osteomyelitis. METHODS: A 28 day antibiotic therapy with a subcutaneous injection of tigecycline (14 mg/kg twice daily), with and without oral rifampicin (40 mg/kg twice daily); or subcutaneous administration of vancomycin (30 mg/kg twice daily), with and without oral rifampicin (40 mg/kg twice daily) were compared. Osteomyelitis was induced with an intramedullary injection of 10(6) colony-forming units of MRSA. Infected rabbits were randomly divided into six groups: tigecycline, tigecycline with oral rifampicin, vancomycin, vancomycin with oral rifampicin, and no treatment control and tigecycline bone penetration groups. Treatment began 2 weeks after infection. After 4 weeks of therapy, the rabbits were left untreated for 2 weeks. Rabbits were then euthanized, and the tibias were harvested. The bones were cultured, and bacterial counts of MRSA were performed. RESULTS: Rabbits that received tigecycline and oral rifampicin therapy (n=14) showed a 100% infection clearance. Rabbits treated with tigecycline (n=10) showed a 90% clearance. Rabbits treated with vancomycin and oral rifampicin (n=10) also showed a 90% clearance. Rabbits treated with vancomycin (n=11) showed an 81.8% clearance. Untreated controls (n=15) demonstrated only a 26% clearance. For the tigecycline bone penetration group, the bone concentrations of tigecycline in the infected tibia were significantly higher than the non-infected ones. CONCLUSIONS: Tigecycline may be an effective alternative to vancomycin in the treatment of MRSA osteomyelitis.

An articulated antibiotic spacer used for infected total knee arthroplasty: a comparative in vitro elution study of Simplex and Palacos bone cements.

For the staged management of infected total knee arthroplasty (TKA), antibiotic laden polymethylmethacrylate (PMMA) spacers have been recommended. Antibiotic-impregnated PMMA spacers target drug delivery, achieving high local levels while limiting the potential for host toxicity associated with parenteral antimicrobial therapy. This study examined the elution characteristics of an articulating PMMA TKA spacer that has been useful clinically. Tobramycin and vancomycin are both active against many organisms leading to joint infections. We used various combined antibiotic concentrations (maintaining a relative ratio of 55% tobramycin to 45% vancomycin w/w), and then assayed the elution profile of the TKA spacer in vitro. Additionally, the elution qualities of two brands of bone cement, Simplex and Palacos, were compared. Briefly, three groups of PMMA spacers, impregnated with different antibiotic loads, were fashioned from a mold replicating a femoral TKA component. The entire spacer surface area was immersed in sterile phosphate buffered saline (PBS) in a 1:6 ratio of grams of cement to milliliters of PBS and incubated at 37 degrees C for 24 h. After 24 h, aliquot eluates were taken, the PBS discarded, and replaced with fresh, sterile PBS. PBS was changed daily and an aliquot was taken at least weekly for nine weeks. Eluate samples were stored at -70 degrees C until assayed. Each spacer eluate sample's antibiotic concentration was determined by disc diffusion bioassay against Bacillus subtilis. Mean zone inhibition diameters were extrapolated from the standard curve to yield micrograms per milliliter of antibiotic in PBS. In all groups the Palacos spacers demonstrated higher elution levels, above the MIC for the organism used, for a longer period of time than those made with Simplex. Based on the observed elution profiles, antibiotic-impregnated Palacos bone cement may offer a more effective vehicle for local drug delivery during staged treatment of infected TKA.

Trends in utilization and outcomes of laparoscopic versus open appendectomy.

BACKGROUND: Although a number of trials have analyzed the outcomes of laparoscopic versus open appendectomy, the clinical advantages, and cost-effectiveness of laparoscopic appendectomy in the management of acute and perforated appendicitis are still not clearly defined. The aim of this study was to examine utilization and outcomes of laparoscopic versus open appendectomy using a national administrative database of academic medical centers and teaching hospitals. METHODS: Using ICD-9 diagnosis and procedure codes, we obtained data from the University HealthSystem Consortium Clinical Data Base for all patients who underwent appendectomy for acute and perforated appendicitis between 1999 and 2003 (n = 60,236). Trends in utilization of laparoscopic appendectomy were examined over the 5-year period. The outcomes of laparoscopic and open appendectomy were compared including length of hospital stay, 30-day readmission, complications, observed and expected (risk-adjusted) in-hospital mortality, and costs. RESULTS: Overall, 41,085 patients underwent open appendectomy and 19,151 patients underwent laparoscopic appendectomy. The percentage of appendectomy performed by laparoscopy increased from 20% in 1999 to 43% in 2003 (P <0.01). Compared with patients who underwent open appendectomy, patients who underwent laparoscopic appendectomy were more likely female, more likely white, had a lower severity of illness, and were less likely to have perforated appendicitis. Laparoscopic appendectomy was associated with a shorter length of hospital stay (2.5 days vs 3.4 days), lower rate of 30-day readmission (1.0% vs 1.3%), and lower rate of overall complications (6.1% vs 9.6%). There was no significant difference in the observed to expected mortality ratio between laparoscopic and open appendectomy (0.5 vs 0.6, respectively). The mean cost per case was similar between the two groups (US$ 6,242 vs US$ 6,260). CONCLUSIONS: Utilization of laparoscopic appendectomy at academic centers has increased more than two-fold between 1999 and 2003. Patients selected for laparoscopic appendectomy have less advanced appendicitis and have a shorter length of stay and fewer complications without increasing the inpatient care cost.

The efficacy of fibrin sealant in prevention of anastomotic leak after laparoscopic gastric bypass.

BACKGROUND: Anastomotic leak after laparoscopic gastric bypass (GBP) can result in significant morbidity, mortality, and consumption of healthcare resources. Fibrin sealant has been used clinically in the prevention of leak; however, its efficacy has not been clearly demonstrated. The aims of this study were to (1) develop an iatrogenic leak model in swine, (2) examine the efficacy of fibrin sealant in sealing iatrogenic anastomotic leak, and (3) review our experience with the use of fibrin sealant in 66 patients who underwent laparoscopic GBP. METHODS: This study was performed in three phases. In phase 1, laparoscopic gastrojejunostomy was performed in adult swine with iatrogenic disruption of the anastomotic staple line. The size of disruption was sequentially increased (6- to 12-F opening) until a leak model was developed. In phase 2, 16 animals underwent laparoscopic gastrojejunostomy with a 12-F disruption of the anastomosis; 10 animals (study group) had fibrin sealant (Tisseel VH) applied on the disrupted anastomosis and 6 animals (control group) did not receive fibrin sealant. Animals were sacrificed on postoperative day 5 or earlier if peritonitis developed and were examined for sealing of the anastomotic disruption and the presence of intraabdominal abscess. In phase 3, the outcome of 66 consecutive patients who underwent laparoscopic GBP with fibrin sealant applied at the gastrojejunostomy was reviewed. RESULTS: In phase 1, an anastomotic leak model was developed with a 12-F disruption of the staple line. In phase 2, two control animals required early sacrifice for bile peritonitis; three control animals had intraabdominal abscess discovered at sacrifice and one animal did not have any evidence of intraabdominal abscess or leak. Of the 10 animals in the study group, all survived until sacrifice and none of these animals had evidence of intraabdominal abscess or persistent leak. Therefore, 83% of animals in the control group developed either leak or abscess compared to 0% in the study group (P < 0.01, Fisher's exact test). Clinically, no leak or intraabdominal abscess developed in 66 patients who underwent laparoscopic GBP with the use of fibrin sealant. CONCLUSIONS: An anastomotic leak model was developed in swine with disruption of the stapled gastrojejunostomy to a 12-F opening. The use of fibrin sealant significantly reduces leak and abscess complication. Our results support the tissue sealing property of fibrin sealant and its use on high-risk gastrointestinal anastomosis.

The practice of bariatric surgery at academic medical centers.

The growing demand for laparoscopic bariatric surgery has led to an increase in the development of new bariatric surgical practices. Proper hospital facilities and an experienced bariatric surgical team are necessary to ensure optimal patient results. We surveyed academic centers participating in the University HealthSystem Consortium to examine the current practice of bariatric surgery. The survey questioned (1) availability of resources and equipment designed for the morbidly obese, (2) accidents, equipment problems, and workers' compensation relating to the care of bariatric surgical patients, (3) credentialing of bariatric surgeons, and (4) suggestions for improvements in the bariatric surgery program. Twenty-five institutions that perform bariatric surgery responded. Although the majority of institutions noted that they had basic bariatric equipment, some organizations did not have facility resources such as high-weight operating room tables and computed tomography scanners or transfer devices. Twenty-eight percent of institutions reported having accidents or equipment problems and 40% of institutions had workers' compensation claims relating to the care of bariatric patients. With regard to credentialing, 60% of institutions required the surgeons to have performed a minimum number of procedures prior to granting privileges. Suggested improvements included the need for more specialized bariatric equipment, enhancement of the education of all members of the bariatric surgical team, and designation of a bariatric physician who would coordinate care. This survey of bariatric surgery practices at academic medical centers demonstrates that the practice of bariatric surgery could be improved with regard to availability of bariatric equipment and resources and credentialing of surgeons.

The relationship between hospital volume and outcome in bariatric surgery at academic medical centers.

OBJECTIVE: To examine the effect of hospital volume of bariatric surgery on morbidity, mortality, and costs at academic centers. SUMMARY BACKGROUND DATA: The American Society for Bariatric Surgery recently proposed categorization of certain bariatric surgery centers as "Centers of Excellence." Some of the proposed inclusion criteria were hospital volume and operative outcomes. The volume-outcome relationship has been well established in several complex abdominal operations; however, few studies have examined this relationship in patients undergoing bariatric surgery. METHODS: Using the International Classification of Diseases, 9th edition, diagnosis and procedure codes, we obtained data from the University HealthSystem Consortium Clinical Data Base for all patients who underwent Roux-en-Y gastric bypass for the treatment of morbid obesity between 1999 and 2002 (n = 24,166). Outcomes of bariatric surgery, including length of hospital stay, 30-day readmission, morbidity, observed and expected (risk-adjusted) mortality, and costs were compared between high-volume (>100 cases/year), medium-volume (50-100 cases/year), and low-volume hospitals (<50 cases/year). RESULTS: There were 22 high-volume (n = 13,810), 27 medium-volume (n = 7634), and 44 low-volume (n = 2722) hospitals included in our study. Compared with low-volume hospitals, patients who underwent gastric bypass at high-volume hospitals had a shorter length of hospital stay (3.8 versus 5.1 days, P < 0.01), lower overall complications (10.2% versus 14.5%, P < 0.01), lower complications of medical care (7.8% versus 10.8%, P < 0.01), and lower costs ($10,292 versus $13,908, P < 0.01). The expected mortality rate was similar between high- and low-volume hospitals (0.6% versus 0.6%), demonstrating similarities in characteristics and severity of illness between groups. The observed mortality, however, was significantly lower at high-volume hospitals (0.3% versus 1.2%, P < 0.01). In a subset of patients older than 55 years, the observed mortality was 0.9% at high-volume centers compared with 3.1% at low-volume centers (P < 0.01). CONCLUSIONS: Bariatric surgery performed at hospitals with more than 100 cases annually is associated with a shorter length of stay, lower morbidity and mortality, and decreased costs. This volume-outcome relationship is even more pronounced for a subset of patients older than 55 years, for whom in-hospital mortality was 3-fold higher at low-volume compared with high-volume hospitals. High-volume hospitals also have a lower rate of overall postoperative and medical care complications, which may be related in part to formalization of the structures and processes of care.

Bowel obstruction after laparoscopic Roux-en-Y gastric bypass.

BACKGROUND: Bowel obstruction has been frequently reported after laparoscopic Roux-en-Y gastric bypass (LRYGBP). The aim of this study was to review our experience with bowel obstruction following LRYGBP, specifically examining its etiology and management and to strategize maneuvers to minimize this complication. METHODS: We retrospectively reviewed the charts of 9 patients who developed postoperative bowel obstruction after LRYGBP. Each chart was reviewed for demographics, timing of bowel obstruction from the primary operation, etiology of obstruction, and management. RESULTS: 9 of our initial 225 patients (4%) who underwent LRYGBP developed postoperative bowel obstruction. The mean age was 46 +/- 12 years, with mean BMI 47 +/- 9 kg/m(2). 6 patients developed early bowel obstruction, and 3 patients developed late bowel obstruction. The mean time interval for development of early bowel obstruction was 16 +/-16 days. The causes for early bowel obstruction included narrowing of the jejunojenunostomy anastomosis (n=3), angulation of the Roux limb (n=2), and obstruction of the Roux limb at the level of the transverse mesocolon (n=1). The mean time interval for development of late bowel obstruction was 7.4 +/- 0.5 months. The causes for late bowel obstruction included internal herniation (n=2) and adhesions (n=1). 6 of 9 bowel obstructions (66%) were considered technically related to the learning curve of the laparoscopic approach. Eight of the 9 patients required operative intervention, and 6 of the 8 reoperations were managed laparoscopically. Management included laparoscopic bypass of the jejunojejunostomy obstruction site (n=5), open reduction of internal hernia (n=2), and laparoscopic lysis of adhesion (n=1). CONCLUSIONS: Bowel obstruction is a frequent complication after LRYGBP, particularly during the learn ing curve of the laparoscopic approach. Specific measures should be instituted to minimize bowel obstruction after LRYGBP as most of these complications are considered technically preventable.

Incidence and outcome of anastomotic stricture after laparoscopic gastric bypass.

Anastomotic stricture is a frequent complication after Roux-en-Y gastric bypass (GBP). We evaluated the frequency of anastomotic stricture following laparoscopic GBP using a 21 mm. vs. a 25 mm circular stapler for construction of the gastrojejunostomy and the safety and efficacy of endoscopic balloon dilation in the management of anastomotic stricture. We reviewed data on 29 patients in whom anastomotic strictures developed after laparoscopic GBP. All strictures were managed with endoscopic balloon dilation using an 18 mm balloon catheter under fluoroscopic guidance. Main outcome measures were the number of anastomotic strictures in patients in whom the 21 mm (vs. 25 mm) circular stapler was used to create the gastrojejunostomy, time interval between the primary operation and symptoms, complications of endoscopic balloon dilation, the number of patients with resolution of obstructive symptoms, and body weight loss. There were 28 females with a mean age of 39 years and a mean body mass index of 48 kg/m(2). Anastomotic stricture occurred significantly more frequently with the use of the 21 mm compared to the 25 mm circular stapler (26.8% vs. 8.8%, respectively; P<0.01). The median time interval between the primary operation and presentation of stricture was 46 days. After the initial dilation, recurrent stricture developed in 5 (17.2%) of 29 patients. These five patients underwent a second endoscopic dilation, and only one of these five patients required a third endoscopic dilation. None of the 29 patients required more than three endoscopic dilations. The mean percentage of excess body weight loss at 1 year for patients in whom the 21 mm circular stapler was used for creation of the gastrojejunostomy was similar to that for patients in whom the 25 mm circular stapler was used (68.2% vs. 70.2%, P=0.8). In this series the rate of anastomotic stricture significantly decreased with the use of the 25 mm circular stapler for construction of the gastrojejunostomy without compromising weight loss. Endoscopic balloon dilation is a safe and effective option in the management of anastomotic stricture following laparoscopic GBP.

Complications after laparoscopic gastric bypass: a review of 3464 cases.

HYPOTHESIS: The type and frequency of complications after open Roux-en-Y gastric bypass (GBP) have changed with the development of laparoscopic technique. BACKGROUND: The number of laparoscopic GBP cases performed in the United States has increased dramatically during the past several years. We compared the type and frequency of complications after laparoscopic and open GBP. METHODS: We searched MEDLINE from January 1, 1994, through December 31, 2002, using the keywords morbid obesity, laparoscopy, bariatric surgery, and gastric bypass. We selected studies on laparoscopic or open GBP with more than 50 patients and published in the English language for analysis. We excluded studies with reoperative Roux-en-Y GBP cases or other bariatric procedures. The type and frequency of postoperative complications were recorded from each study. We used chi2 and Fisher exact tests to determine statistical significance. RESULTS: Ten laparoscopic GBP studies with 3464 patients and 8 open GBP studies with 2771 patients were considered. The mean of the reported average age for patients undergoing laparoscopic GBP was 41 years compared with 43 years for open GBP. The mean percentages of female patients were 87% for laparoscopic GBP and 82% for open GBP; the mean reported average body mass index (calculated as weight in kilograms divided by the square of height in meters), 48.7 and 49.5, respectively. Compared with open GBP, laparoscopic GBP was associated with a decrease in the frequency of iatrogenic splenectomy, wound infection, incisional hernia, and mortality; however, there was an increase in the frequency of early and late bowel obstruction, gastrointestinal tract hemorrhage, and stomal stenosis. There were no significant differences in the frequency of anastomotic leak, pulmonary embolism, or pneumonia. CONCLUSIONS: The type and frequency of postoperative complications after laparoscopic and open GBP are different. Certain complications increase with laparoscopic GBP, probably owing to the learning curve of this complex procedure, whereas other complications decrease because of the advantages of the smaller access incision.

Treatment of experimental osteomyelitis with a fibrin sealant antibiotic implant.

Two methods currently are available for the delivery of antibiotics: intravenous injection with a long-term indwelling catheter and local implant of antibiotic-containing polymethylmethacrylate beads. Both of these methods have significant disadvantages. A fibrin sealant implant, impregnated with tobramycin, was evaluated in a rabbit model of osteomyelitis to determine whether it has the potential of supplying a basis for bone reconstruction and providing an improved treatment method for the delivery of antibiotics to orthopaedic infections. Localized tibial osteomyelitis, with methicillin-sensitive Staphylococcus aureus, was developed surgically in female New Zealand White rabbits. After 2 weeks, rabbits with evidence of osteomyelitis were treated with debridement alone, debridement plus systemic tobramycin, debridement plus fibrin sealant, debridement plus fibrin sealant loaded with tobramycin, polymethylmethacrylate beads loaded with tobramycin, or not treated at all (control). After 4 weeks of therapy, the rabbits were sacrificed and the involved bones were cultured for concentrations of methicillin-sensitive Staphylococcus aureus per gram of bone and marrow. Preliminary data (N = 14) indicate fibrin sealant plus tobramycin may be as effective as polymethylmethacrylate beads plus tobramycin against methicillin-sensitive Staphylococcus aureus osteomyelitis in a rabbit model.