Andrea L. Jester

Experimental Abdominal Aortic Aneurysm Formation Is Mediated by IL-17 and Attenuated by Mesenchymal Stem Cell Treatment

Background— Abdominal aortic aneurysm (AAA) formation is characterized by inflammation, smooth muscle activation and matrix degradation. This study tests the hypothesis that CD4+ T-cell–produced IL-17 modulates inflammation and smooth muscle cell activation, leading to the pathogenesis of AAA and that human mesenchymal stem cell (MSC) treatment can attenuate IL-17 production and AAA formation. Methods and Results— Human aortic tissue demonstrated a significant increase in IL-17 and IL-23 expression in AAA patients compared with control subjects as analyzed by RT-PCR and ELISA. AAA formation was assessed in C57BL/6 (wild-type; WT), IL-23−/− or IL-17−/− mice using an elastase-perfusion model. Heat-inactivated elastase was used as control. On days 3, 7, and 14 after perfusion, abdominal aorta diameter was measured by video micrometry, and aortic tissue was analyzed for cytokines, cell counts, and IL-17–producing CD4+ T cells. Aortic diameter and cytokine production (MCP-1, RANTES, KC, TNF-&agr;, MIP-1&agr;, and IFN-&ggr;) was significantly attenuated in elastase-perfused IL-17−/− and IL-23−/− mice compared with WT mice on day 14. Cellular infiltration (especially IL-17–producing CD4+ T cells) was significantly attenuated in elastase-perfused IL-17−/− mice compared with WT mice on day 14. Primary aortic smooth muscle cells were significantly activated by elastase or IL-17 treatment. Furthermore, MSC treatment significantly attenuated AAA formation and IL-17 production in elastase-perfused WT mice. Conclusions— These results demonstrate that CD4+ T-cell–produced IL-17 plays a critical role in promoting inflammation during AAA formation and that immunomodulation of IL-17 by MSCs can offer protection against AAA formation.

Impact of omphalocele size on associated conditions

PURPOSE Omphalocele is often associated with the presence of other congenital anomalies. Case reports have demonstrated nonclassical associations occurring in smaller omphaloceles. The aim of this study was to determine if omphalocele defect size correlates with the type of anomalies found. METHODS Patient records at a pediatric hospital were retrospectively reviewed for an 8-year period. Data were collected on patient demographics, omphalocele size, and congenital anomalies identified. Size of the abdominal wall defect was determined by either physical examination or operative record of repair. Patient cohorts were designated as those with small (4 cm and less) or large (greater than 4 cm) omphaloceles. RESULTS Fifty-three cases of omphalocele were observed. Twenty-seven cases were classified as small, with 26 classified as large. A predominance of males was noted in the small omphalocele group (78% vs 42%; P = .01). Intestinal anomalies, including Meckels diverticulum and intestinal atresia, were only seen in patients with small omphaloceles. Most cardiac anomalies were associated with large omphaloceles (34.6% vs 3.7%; P = .01). CONCLUSION Small omphalocele size correlates with an increased prevalence of associated gastrointestinal anomalies, a lower prevalence of cardiac anomalies, and a higher predominance of male sex.

Preoperative prediction of need for fundoplication before gastrostomy tube placement in children.

PURPOSE Percutaneous endoscopic gastrostomy (PEG) tube placement is a common procedure performed for children with oral aspiration and failure to thrive. The concurrent presence of gastroesophageal reflux (GER) may be difficult to diagnose in these children and may dictate the need for an antireflux procedure. The purpose of this study was to review our preoperative evaluation of children undergoing PEG placement to better elucidate preoperative factors that may require eventual fundoplication. METHODS A retrospective review at a tertiary care, childrens hospital between May 2002 and August 2007 was performed of patients undergoing PEG placement. Patients were identified through database search by operative procedure codes. Patient groups were defined as those undergoing PEG alone (group 1) and those requiring fundoplication after prior PEG (group 2). Comparison of patient demographics and radiologic qualitative results of GER was analyzed using chi(2) analysis, with significance determined at P < .05. RESULTS A total of 863 patients underwent PEG placement over this 64-month period. A sampled cohort of patients undergoing PEG over a year comprised group 1. Forty-four patients (5.1%) underwent Nissen fundoplication after prior PEG placement (group 2). Patient demographics were similar between the groups. Comparison of comorbid conditions and qualitative indicators of GER between the groups showed only cerebral palsy had a significantly higher associated risk of GER that required antireflux surgery. Preoperative clinical assessment had a 95% positive predictive value in identifying children who required only PEG. CONCLUSIONS Despite the high predictive value of individualized clinical assessment in the ultimate decision for gastrostomy without need of fundoplication, further studies are needed to determine whether children with conditions such as cerebral palsy may require a concurrent antireflux surgery at the time of gastrostomy.

The effects of age at implantation on speech intelligibility in pediatric cochlear implant users: Clinical outcomes and sensitive periods

This study assessed the effects of age at implantation on the speech intelligibility of congenitally, profoundly deaf pediatric cochlear implant users. The children received implants during the first eight years of life and were divided into subgroups based on their age at implantation. The childrens tape recordings of standard sentences were digitized and played back to normal-hearing listeners who were unfamiliar with deaf speech. Intelligibility was measured as the number of words correctly identified averaged across all listeners. The data showed that earlier implantation had a positive and significant effect on the speech intelligibility of cochlear implant users. The results also suggested that a gradual decline in the ability to acquire spoken language skills may occur over time and, furthermore, cochlear implantation before the age of two years may yield significantly better speech intelligibility outcomes than later implantation.

Management of vascular trauma from dog bites

BACKGROUND Vascular trauma from large-dog bites present with a combination of crush and lacerating injuries to the vessel, as well as significant adjacent soft tissue injury and a high potential for wound complications. This retrospective case series evaluates our 15 years of experience in managing this uncommonly seen injury into suggested treatment recommendations. METHODS From our database, 371 adult patients presented with dog bites between July 1997 and June 2012. Twenty (5.4%) of those patients had vascular injuries requiring surgical intervention. Patient demographics, anatomic location of injury, clinical presentation, imaging modality, method of repair, and complication rates were reviewed to assess efficacy in preserving limb function. Pediatric patients were managed at the regional childrens hospital and, therefore, not included in this study. RESULTS Among the 20 surgically treated vascular injuries, there were 13 arterial-only injuries, two venous-only injuries, and five combination arterial and venous injuries. Seventeen patients (85%) had upper extremity injuries; three patients had lower extremity injuries (15%). The axillobrachial artery was the most commonly injured single vessel (n = 9/20; 45%), followed by the radial artery (n = 4/20; 20%). Surgical repair of vascular injuries consisted of resection and primary anastomosis (four), interposition bypass of artery with autogenous vein (13), and ligation (two), with (one) being a combination of bypass and ligation. All patients had debridement of devitalized tissue combined with pulse lavage irrigation and perioperative antibiotics. Associated injuries requiring repair included muscle and skin (n = 10/20; 50%), bone (n = 1/20; 5%), nerve (n = 1/20; 5%), and combinations of the three (n = 5/20; 25%). Postoperative antibiotic therapy was administered for 14.7 ± 8.2 days in all 20 patients. Four patients (20%) developed postoperative wound infections, although this did not compromise their vascular repair. Of the patients compliant with postoperative surveillance, all limbs (100%) were viable at discharge and at 1-year follow-up. CONCLUSIONS Dog bite vascular injuries are an uncommon occurrence, where extremity pulse abnormalities are the most common presentation. These injuries are also associated with significant adjacent soft tissue trauma, which warrants aggressive debridement and perioperative antibiotic therapy. Despite vigilant management, nearly one-fifth of our patients sustained wound infections. All infections were successfully managed with broad-spectrum antibiotics, and all limbs were preserved 1-year postoperatively.

Transgastric Pancreatic Necrosectomy: How I Do It

Necrotizing pancreatitis is a serious medical problem that often requires intervention to debride necrotic pancreatic and peripancreatic tissue. Recently, minimally invasive approaches have been applied to pancreatic necrosectomy. The purpose of this report is to review the history of transgastric pancreatic debridement, identify appropriate patient selection criteria, and highlight technical “pearls.” We present this subject matter in the context of our own clinical experience, with a primary focus on a “How I Do It” type of technical description.

Impact of Fellow Versus Resident Assistance on Outcomes Following Pancreatoduodenectomy

BackgroundParticipation by surgical trainees in complex procedures is key to their development as future practicing surgeons. The impact of surgical fellows versus general surgery resident assistance on outcomes in pancreatoduodenectomy (PD) has not been well studied. The purpose of this study was to determine differences in patient outcomes based on level of surgical trainee.MethodsConsecutive cases of PD (n = 254) were reviewed at a single high-volume institution over a 2-year period (July 2013–June 2015). Thirty-day outcomes were monitored through the American College of Surgeon’s National Surgical Quality Improvement Program (NSQIP) and Quality In-Training Initiative. Patient outcomes were compared between PD assisted by general surgery residents versus hepatopancreatobiliary fellows.ResultsThe hepatopancreatobiliary surgery fellows and general surgery residents participated in 109 and 145 PDs, respectively. The incidence of each individual postoperative complication (renal, infectious, pancreatectomy-specific, and cardiopulmonary), total morbidity, mortality, and failure to rescue were the same between groups.ConclusionsPatient operative outcomes were the same between fellow- and resident-assisted PD. These results suggest that hepatopancreatobiliary surgery fellows and general surgery residents should be offered the same opportunities to participate in complex general surgery procedures.

Rectus Sheath Pressure as a Novel Diagnostic Adjunct for Abdominal Compartment Syndrome

Abdominal compartment syndrome (ACS) can be difficult to diagnose in patients with increasing numbers of comorbidities [1]. Intra-abdominal hypertension is important in the diagnosis of ACS and is most frequently measured by bladder pressures. However, several practical considerations as well as patient characteristics complicate the use of bladder pressures and interpretation of the results. Non-standard techniques in measurement often result in a confusing picture for a surgeon deciding whether or not to offer a decompressive laparotomy. Recent steps to standardize bladder pressure measurement [2] will hopefully aid in the reliability. However, in spite of standardization of measurement, one of the more common populations monitored for ACS is trauma patients, where pelvic fractures and/or bladder perforations cast doubt on bladder pressure readings. Finally, non-trauma patients with previous genitourinary procedures or comorbidities, such as cystectomy/neobladder and neurogenic bladder can render bladder pressure monitoring impossible or unreliable. In a recent article published in the Journal of Surgical Research, Benninger and colleagues propose a complimentary option for measuring intra-abdominal hypertension [3]. In a porcine model, the authors showed correlation between rectus sheath compartment pressure and intra-abdominal pressure as measured by carbon dioxide peritoneal insufflations. This clinically relevant model accurately reflects the pathophysiology of ACS; however, the authors did not report the physiologic consequences of the induced ACS, such as derangements in renal and cardiopulmonary function. The authors were careful to mention that the catheter placement was confirmed after the measurements were recorded, but did not report any catheter-related complications. The accuracy of placement of these pressure transducing catheters is still to be determined. Interestingly, they advocated ultrasound guidance for placement, which would certainly increase the confidence of a properly positioned catheter. Lastly, the authors did not comment on the increasing size of adult patients, which would necessitate longer and longer catheters to reach (and remain in) the rectus sheath. The current study represents the latest installment of an interesting line of research by this laboratory in smaller models [4]. This larger model brings us closer to patient applicability, and we look forward to an ethically