Initial Inoculation Concentration Does Not Affect Final Bacterial Colonization of In vitro Vascular Conduits.

BACKGROUND: Despite improved peri-operative care, prosthetic graft infections continue to cause substantial morbidity and mortality. Contemporary graft infection models have tested a conduit's infectability using varying concentrations without standardization. Using a static assay in vitro model, we sought to evaluate the impact of inoculation concentration on vascular conduit attachment. METHODS: The 2-hour and 24-hour attachment of Staphylococcus aureus TCH1516 and Pseudomonas aeruginosa PA01-UW were determined on polytetrafluoroethylene (PTFE), Dacron®, nitinol, cobalt chromium, and Viabahn® (W.L. Gore and Associates, Newark, DE) endoprotheses. Individually and in combination, concentrations at 104, 105, 106, 107, and 108 were tested on 2-mm sections of each graft. After each time interval, the prosthetics were rinsed to remove non-attached bacteria, sonicated to release the attached bacteria, spiral plated, and then analyzed for the attached concentration. RESULTS: After two hours, the higher initial inoculation concentration translated into a higher attachment percentage, but the mean attachment percentage was only 14.8% in the 108 group. Pseudomonas aeruginosa had the greatest mean attachment across all material and concentration groups. The sequence of attachment on the conduits followed a constant order: Dacron, PTFE, cobalt, nitinol, and Viabahn with no difference between Dacron and PTFE. Although there were still differences at the 24-hour mark, the median attachment at each concentration was greater than the highest initial concentration (108). CONCLUSIONS: Initial attachment percentage is poor consistently regardless of inoculation concentration, however, Staphylococcus aureus and Pseudomonas aeruginosa are still able to achieve full attachment after 24 hours. A concentration of less than 107 should be used in vascular graft infection models to ensure adequate bacterial attachment.

Antimicrobial-bonded graft patency in the setting of a polymicrobial infection in swine (Sus scrofa).

BACKGROUND: Polytetrafluoroethylene (PTFE) and Dacron are commonly used as arterial conduits in vascular trauma or infection when vein interposition graft may not be available. This study used a previously validated large animal model of polymicrobial infection to assess the patency and infectious resistance of a novel, antibiotic-impregnated graft material compared with PTFE and Dacron. METHODS: Forty-eight animals were placed into five groups for a 21-day survival period. A 6-mm PTFE, Dacron, or antimicrobial-bonded graft was used to replace the iliac artery and then inoculated with 1 × 107 colonies/mL of genetically labeled Pseudomonas aeruginosa and Staphylococcus aureus. Native vessels with and without contamination served as control groups. The primary end points were graft patency (determined by duplex ultrasound and necropsy) and graft infection (culture with molecular analysis). Secondary end points included physiologic measurements, blood cultures, laboratory data, and histopathology. RESULTS: At 21 days, 50% of PTFE, 62.5% of Dacron, and 100% of the antimicrobial-bonded grafts remained patent (P = .04). PTFE and Dacron had an equivalent number of overall infections, 87.5% and 75%, respectively (P = 1.0). There was no significant difference of infectious organisms between standard materials. The infection rate of the antimicrobial-bonded graft (25%) was significantly less than that of both PTFE and Dacron (P < .01), and all of these infections were secondary to P. aeruginosa. Clinical data did not vary significantly between groups. There were no mortalities in the protocol secondary to graft blowout or sepsis. CONCLUSIONS: The antimicrobial-bonded graft material outperformed standard PTFE and Dacron in the setting of polymicrobial infection with regard to graft patency and infection. The novel prosthetic material appears to be resistant to infection with S. aureus and to limit the growth of P. aeruginosa. Additional studies are recommended to explore the role of this antibiotic-bonded graft for use in the setting of vascular infection or trauma.

Quality of Life in United States Veterans With Combat-Related Ostomies From Iraq and Afghanistan.

OBJECTIVE: Assess the impact of ostomy formation on quality of life for U.S. Service Members. METHODS: U.S. personnel sustaining colorectal trauma from 2003 to 2011 were identified using the Department of Defense Trauma Registry. A cross-sectional observational study was conducted utilizing prospective interviews with standard survey instruments. Primary outcome measures were the Stoma Quality of Life Scale and Veterans RAND 36 scores and subjective responses. Patients with colorectal trauma not requiring ostomy served as controls. RESULTS: Of 177 available patients, 90 (50.8%) male veterans consented to participate (55 ostomy, 35 control). No significant differences were observed between ostomy and control groups for Injury Severity Score (25.6 ± 9.9 vs. 22.9 ± 11.8, p = 0.26) or mechanism of injury (blast: 55 vs. 52%, p = 0.75); nonostomates had fewer anorectal injuries (3.2 vs. 47.9%, p < 0.01). Median follow-up was 6.7 years. Veterans RAND-36 Physical and Mental Component Scores were similar between groups. About 45.8% of ostomates were willing-to-trade a median of 10 years (interquartile range = 5-15) of their remaining life for gastrointestinal continuity. At last follow-up, 95.9% of respondents' combat-related ostomies were reversed with a median duration of 6 (range = 3-19) months diverted. CONCLUSIONS: Ostomy creation in a combat environment remains safe and does not have a quantifiable impact on long-term quality of life.

Prosthetic Graft Patency in the Setting of a Polymicrobial Infection in Swine (Sus scrofa).

BACKGROUND: In the setting of vascular injury, vein interposition graft is the preferred conduit, but may have limited availability. This study seeks to develop a large animal model assessing the graft performance of polytetrafluoroethylene (PTFE) and Dacron in the setting of a polymicrobial infection. METHODS: Thirty-seven animals were placed into 4 groups for a 21-day survival period. Six-millimeter PTFE or Dacron interposition grafts were placed in the right iliac artery with a standardized bacterial inoculation. Native vessel with and without contamination served as control groups. The inoculant was 1 × 107 of genetically labeled Pseudomonas aeruginosa and Staphylococcus aureus. The primary end points were graft patency (determined by duplex ultrasound and necropsy) and graft infection (culture with molecular analysis). Secondary end points included physiological measurements, blood cultures, laboratory data, and histopathology. RESULTS: PTFE and Dacron had similar infection rates of 85.7% and 75%, respectively. There was no significant difference in infectious organisms between graft materials. PTFE and Dacron exhibited bacterial ingrowth and transmigration to the intraluminal portion of the conduit. Forty-five percent of the Dacron group and 40% of the PTFE group remained patent at postoperative day 21 (P = 0.98). Clinical data, including white blood cell count, percent neutrophils, and lactate, did not vary significantly between groups. CONCLUSIONS: PTFE and Dacron perform similarly in terms of infection rates and graft failure as both have a propensity toward bacterial ingrowth and occlusion when compared with controls. This is a valid animal model to assess graft performance in the setting of polymicrobial infection and provides an avenue for studying novel prosthetic conduits.

A critical review of the role of local excision in the treatment of early (T1 and T2) rectal tumors.

The optimal treatment of early (T1 and T2) rectal adenocarcinomas remains controversial. Local excision and radical resection with total mesorectal excision are the two surgical techniques for excising early rectal cancer. Each has their respective benefits, with local excision allowing for decreased operative morbidity and mortality while radical resection provides an oncologically complete treatment through lymphadenectomy. Local excision can be accomplished via transanal endoscopic microsurgery or transanal excision. There is no significant difference in the recurrence rates (21% vs. 33%) or overall survival (80% vs. 66%) between the two local excision modalities; however, transanal endoscopic microsurgery does allow for a higher rate of R0 resection. Current selection criteria for local excision include well to moderately differentiated tumors without high-risk features such as lymphovascular invasion, perineural invasion, or mucinous components. In addition, tumors should ideally be <3 cm in size, excised with a clear margin, occupy less than 1/3 of the circumference of the bowel and be mobile/nonfixed. Despite these stringent inclusion criteria, local excision continues to be plagued with a high recurrence rate in both T1 and T2 tumors due to a significant rate of occult locoregional metastases (20% to 33%). For both tumor groups, the recurrence rate in the local excision group is more than double compared to radical resection. However, the overall survival is not significantly different between those with and without metastases. With intense postoperative surveillance, these recurrences can be identified early while they are confined to the pelvis allowing for salvage surgical options. Recently, neoadjuvant therapy followed by local excision has shown favorable short and long-term oncological outcomes to radical resection in the treatment of T2 rectal cancer. Ultimately, the management of early rectal cancer must be individualized to each patient's expectations of quality and quantity of life. With informed consent, patients may be willing to accept a higher failure rate and an increased post-operative surveillance regimen to preserve a perceived increased quality of life.

Validation of the Short Musculoskeletal Function Assessment in patients with battlefield-related extremity vascular injuries.

OBJECTIVE: Vascular extremity injuries can be a significant burden on a patient's long-term quality of life. Currently, no limb-specific surveys have been used to quantify the relation between injury pattern and the resultant physical or psychological impact. The objective of this study was to validate the use of the Short Musculoskeletal Function Assessment (SMFA) in the setting of extremity vascular injury. METHODS: The Joint Theater Trauma Registry was queried and filtered for U.S. troops with an extremity vascular injury isolated to a single limb. Injury and management data were obtained, and the SMFA was administered after patient contact and consent. Validity was analyzed by characterization of SMFA score distribution, correlation with 36-Item Short Form Health Survey (SF-36) scores, and assessment of its discriminative capability to external measures of injury severity (ie, Injury Severity Score [ISS], Mangled Extremity Severity Score [MESS], and Medicare Part A disability qualification). RESULTS: At mean follow-up of 5 years, 164 patients (median age, 25 years; interquartile range, 22-31 years) completed both surveys. The overall SMFA Dysfunction Index was 24.8 ± 15.2 (range, 0-78; skewness, 0.60; floor/ceiling effect, 0%-1.2%; and nonresponse, 0%), and the overall Bother Index was 29.4 ± 20.2 (range, 0-96; skewness, 0.58; floor/ceiling effect, 0%-4.3%; and nonresponse, 0.6%). SF-36 physical component summary scores correlated inversely with the Dysfunction Index (r = -0.64; P < .01), whereas mental component summary scores correlated inversely with the Bother Index (r = -0.59; P < .01). No difference was found in reported scores between those considered severely injured (ISS > 15) and those not severely injured (ISS ≤ 15). However, those with mangled extremities (MESS ≥ 7) reported higher Dysfunction and Bother indices than those with lower scores (P < .05). In addition, patients considered disabled (per Medicare Part A qualifications) reported higher Dysfunction and Bother indices compared with those not considered disabled (P < .05). CONCLUSIONS: Use of the SMFA is validated in those with extremity vascular injuries, and it should be considered an adjunctive tool in evaluating long-term patient outcomes.

Initial management and outcome of modern battlefield anal trauma.

BACKGROUND: Despite the potential for morbidity and permanent lifestyle alteration, few reports exist examining traumatic injury to the anal canal, particularly among modern-day combatants. OBJECTIVE: The aim of this study was to document the incidence, initial surgical management, and long-term outcomes of wartime anal trauma. DESIGN: This study is a retrospective review. DATA SOURCES: Data were compiled from multiple electronic medical record systems, including the Department of Defense Trauma Registry, the Patient Administration Systems and Biostatistics Activity, and the Armed Forces Health Longitudinal Tracking Application. SETTINGS: Combatants were treated at military treatment facilities with surgical capability during the wars in Iraq and Afghanistan, 2003 through early 2011. PATIENTS: All US and coalition combatants sustaining trauma to the anal canal or sphincter musculature were included. MAIN OUTCOME MEASURES: The quantification of incidence, the evaluation of initial treatment approach, and the determination of clinical and surgical factors correlating with restoration or preservation of GI tract continuity were the primary outcomes measured. RESULTS: Anal trauma occurred in 46 combatants, predominantly from blast injury (76.1%). Most (36, 78.2%) underwent fecal diversion. Concurrent severe systemic or intra-abdominal injuries correlated with colostomy creation. Acute anoplasty was attempted in 11 patients (23.7%) but did not influence eventual colostomy reversal. Among 33 US personnel, the permanent colostomy rate was 30.3%. Concurrent injury to the abdomen strongly predicted long-term colostomy (p = 0.009), along with hypogastric arterial ligation (p = 0.05) and pelvic fracture (p = 0.06). LIMITATIONS: This study was limited by the potential underdiagnosis of anal injury and the restricted follow-up of non-US personnel. CONCLUSIONS: Other injuries besides anal trauma typically have guided the decision for fecal diversion, and acute anal repair has rarely been indicated. The majority of patients with anal trauma regained normal GI continuity, although certain pelvic injuries increased the likelihood of permanent colostomy.

Magnetic resonance imaging: occult popliteal artery entrapment syndrome in a young soldier.

BACKGROUND: Popliteal artery entrapment syndrome (PAES) is frequently misdiagnosed because of symptom overlap with other conditions and lack of a definitive diagnostic modality. The incidence is widely variable, although it should be considered in all patients under 50 years with symptoms of lower extremity claudication. Long-term sequelae of PAES include critical limb ischemia, arterial occlusion, and aneurysm formation caused by repetitive external compression. METHODS: We review the case of a 27-year-old soldier originally treated for exertional compartment syndrome with fasciotomies without relief of symptoms. Magnetic resonance imaging (MRI) failed to demonstrate an aberrant slip of the gastrocnemius muscle, which was ultimately found and released on surgical exploration. RESULTS: Surgical exploration and release of an aberrant band of gastrocnemius muscle through a medial approach resulted in significant relief of symptoms and improvement of walking distance. CONCLUSIONS: Healthy athletes without peripheral vascular disease and symptomatic calf and foot claudication should have an early referral to vascular surgery. The risk of false-negative MRI warrants further investigation into provocative, noninvasive imaging modalities to properly classify PAES. This report reviews the literature to discuss the diagnostic challenges, natural history of disease, and surgical interventions for PAES.

Endovascular aortoiliac reconstruction to allow excision of an infected axillobifemoral bypass.

Axillofemoral graft reconstructions were initially intended to restore lower extremity perfusion in high-risk patients with symptomatic aortoiliac atherosclerotic occlusive disease. However, these reconstructions are now relegated to "bailout" procedures for infected grafts or high-risk critical limb ischemia patients that fail endovascular therapy. Infection of an extra-anatomic bypass graft is a challenging complication as it occurs in poor operative candidates with limited revascularization options and failure has a high rate of amputation and mortality. Described is a novel approach using endovascular reconstruction to treat symptomatic Trans-Atlantic Inter-Society Consensus-II type D aortoiliac lesions allowing for complete excision of an infected axillobifemoral bypass.

Combined arteriovenous thrombolytic infusion for refractory renal vein thrombosis.

Acute renal vein thrombosis can rapidly lead to significant impairment and eventual loss of renal function. Classically presenting with flank pain, hematuria, and laboratory markers consistent with acute kidney injury, therapeutic anticoagulation is the mainstay of treatment. However, endovascular surgery offers a safe and effective alternative for renal salvage in the setting of acute renal vein thrombosis. Described is the use of combined arteriovenous thrombolytic infusion for refractory renal vein thromboses to quickly and effectively decrease clot burden in the micro- and macrovenous circulations while limiting systemic exposure.