Shant Shekherdimian

Effect of Race and Socioeconomic Status in the Treatment of Appendicitis in Patients With Equal Health Care Access

BACKGROUND Lower socioeconomic and minority racial/ethnic status have been linked to delays in surgical care and thus higher appendiceal perforation rates. HYPOTHESIS Equal access to health care eliminates the previously reported socioeconomic and racial/ethnic disparities in rates of appendiceal perforation. DESIGN Retrospective cohort study using discharge abstract data and US census data. SETTING Twelve regional Kaiser Permanente hospitals in southern California. PATIENTS A total of 16,156 patients treated for appendicitis. Patients were divided into low, medium, and high groups based on annual household income and educational level, as well as racial/ethnic status (white, black, Hispanic, and Asian). MAIN OUTCOME MEASURES Appendiceal perforation (AP) rate and length of hospitalization (LOH). RESULTS The adjusted odds ratio for AP was lower in Hispanics and similar in blacks and Asians compared with whites. The odds ratio for AP was similar in high- and medium-income families compared with low-income families. The odds ratio for AP was higher in patients with high educational levels and similar in those with medium educational levels compared with low educational levels. The adjusted LOH was longer in blacks, shorter in Hispanics, and similar in Asians compared with whites. The LOH was similar in high- and medium-income families compared with low-income families. The LOH was higher in patients with medium educational levels and similar in those with high educational levels compared with low educational levels. CONCLUSIONS Lower socioeconomic background and minority race/ethnicity did not correlate with higher AP rates or a clinically longer LOH in patients with equal access to care. Based on these findings, we believe that equal health care access leads to equivalent outcomes in all patients with appendicitis.

The feasibility of using an endoluminal device for intestinal lengthening

PURPOSE Prior studies demonstrating the ability to lengthen intestinal segments with mechanical force required devices with extracorporeal components. The feasibility of using a completely implantable device for in vivo intestinal lengthening was evaluated in this study. METHODS Biocompatible Nitinol springs capable of 5-fold expansions were compressed using absorbable sutures and were implanted into isolated segments of proximal jejunum in rats. Springs compressed with nonabsorbable sutures served as controls. The animals were observed with serial abdominal x-rays until the springs became fully expanded. Intestinal segments were then retrieved for histologic analysis. Two-tailed and paired Students t tests were used for statistical analysis. RESULTS Intestinal segments were successfully lengthened in the experimental group from 1.3 +/- 0.3 cm to 4.4 +/- 0.5 cm (P < .001). Maximum spring length was achieved on postoperative day 36 (range, 16-50 days). In the control group, there was also an increase in intestinal lengths, from 1.6 +/- 0.04 cm to 2.9 +/- 0.4 cm (P < .001) (Fig. 4). In percentages, a 250% increase in length was observed in the experimental group vs an 85% increase in the control group (P < .001). Microscopic evaluation of both control and experimental segments revealed gross preservation of intestinal architecture; however, muscular layer hypertrophy and villous atrophy were noted. CONCLUSIONS Continuous mechanical force with an implantable spring successfully lengthened isolated segments of small bowel in an animal model. Although similar results have been demonstrated using other devices, the current device is totally implantable and may be deployed endoscopically.

Intestinal lengthening in rats after massive small intestinal resection

BACKGROUND Prior studies have demonstrated lengthening of normal small intestinal segments using mechanical expanders. The present study assesses the feasibility of intestinal lengthening in rats that have undergone extensive small intestinal resection. METHODS Female rats underwent small intestinal resection. After 6 weeks, the animals underwent the placement of a mechanical expander device with or without gradual mechanical lengthening. After 3 weeks, the intestinal segments were retrieved for analyses. RESULTS Isolated intestinal segments without mechanical lengthening did not change in length, whereas isolated intestinal segments that were mechanically lengthened more than doubled their initial length. The total alkaline phosphatase activity was 2.4 mumol/min in the isolated intestinal segments and 4.9 mumol/min in the mechanically lengthened segments. The total lactase activity was 0.005 mumol/min in the isolated intestinal segments and 0.007 mumol/min in the mechanically lengthened segments. Smooth muscle thickness was 370 mum in the isolated intestinal segments and 530 mum in the mechanically lengthened segments. CONCLUSION Mechanical small bowel lengthening was achieved in intestinal segments after extensive small intestinal resection. There was an increase in the total alkaline phosphatase activity and preservation of the total lactase activity. Mechanical lengthening may be a useful technique to increase intestinal length in patients with short bowel syndrome.

Same-Day Discharge in Laparoscopic Acute Non-Perforated Appendectomy

BACKGROUND Small studies done during the past decade have demonstrated same-day discharge after appendectomy as an option for non-perforated appendicitis. Here we have examined a large cohort to confirm that same-day discharge in acute non-perforated appendicitis is a safe option. STUDY DESIGN This was a retrospective study of patients from 14 Southern California Region Kaiser Permanente medical centers. All patients older than 18 years of age with acute, non-perforated appendicitis who underwent a laparoscopic appendectomy between 2010 and 2014 were included. We compared patients discharged on the day of surgery with patients hospitalized for 1 night. We examined readmission rates, complication rates, postoperative emergency department visits, postoperative diagnostic or therapeutic radiology visits, reoperations, and cost of treatment. RESULTS The cohort was composed of 12,703 patients; 6,710 patients were in the same-day discharge group and 5,993 patients were in the hospitalized group. Patients in the same-day discharge group had a lower rate of readmission within 30 days when compared with the hospitalized group (2.2% vs 3.1%; p < 0.005). In both groups, postoperative rates of visits to emergency or radiology department for diagnostic or therapeutic imaging studies were statistically similar. Postoperative general surgery department visits were slightly higher in the hospitalized group (85% vs 81%; p < 0.001). CONCLUSIONS Adult patients with acute, non-perforated appendicitis can be discharged safely on the day of surgery without higher rates of postoperative complication or readmission rates compared with those hospitalized after surgery. In addition, same-day discharge in this patient group is cost-effective.

Scalability of an endoluminal spring for distraction enterogenesis

INTRODUCTION Techniques of distraction enterogenesis have been explored to provide increased intestinal length to treat short bowel syndrome (SBS). Self-expanding, polycaprolactone (PCL) springs have been shown to lengthen bowel in small animal models. Their feasibility in larger animal models is a critical step before clinical use. METHODS Juvenile mini-Yucatan pigs underwent jejunal isolation or blind ending Roux-en-y jejunojejunostomy with insertion of either a PCL spring or a sham PCL tube. Extrapolated from our spring characteristics in rodents, proportional increases in spring constant and size were made for porcine intestine. RESULTS Jejunal segments with 7mm springs with k between 9 and 15N/m demonstrated significantly increased lengthening in isolated segment and Roux-en-y models. Complications were noted in only two animals, both using high spring constant k>17N/m. Histologically, lengthened segments in the isolated and Roux models demonstrated significantly increased muscularis thickness and crypt depth. Restoration of lengthened, isolated segments back into continuity was technically feasible after 6weeks. CONCLUSION Self-expanding, endoluminal PCL springs, which exert up to 0.6N force, safely achieve significant intestinal lengthening in a translatable, large-animal model. These spring characteristics may provide a scalable model for the treatment of SBS in children.

Spring-mediated distraction enterogenesis in-continuity

PURPOSE Distraction enterogenesis has been investigated as a novel treatment for patients with short bowel syndrome (SBS) but has been limited by loss of intestinal length during restoration and need for multiple bowel surgeries. The feasibility of in-continuity, spring-mediated intestinal lengthening has yet to be demonstrated. METHODS Juvenile mini-Yucatan pigs underwent in-continuity placement of polycaprolactone (PCL) degradable springs within jejunum. Methods used to anchor the spring ends to the intestine included full-thickness sutures and a high-friction surface spring. Spring constant (k) was 6-15N/m. Bowel was examined for length and presence of spring at 1 to 4weeks. RESULTS Animals tolerated in-continuity lengthening without bowel obstruction for up to 29days. In-continuity jejunum with springs demonstrated intestinal lengthening by 1.47-fold ±0.11. Five springs had detached prematurely, and lengthening could not be assessed. Histologically, in-continuity jejunum showed significantly increased crypt depth and muscularis thickness in comparison to normal jejunum. CONCLUSION Self-expanding endoluminal springs placed in continuity could lengthen intestine without obstruction in a porcine model. This is the first study showing safety and efficacy of a self-expanding endoluminal device for distraction enterogenesis. This is proof-of-concept that in-continuity spring lengthening is feasible and demonstrates its therapeutic potential in SBS. LEVEL OF EVIDENCE Level 3.

Mechanical lengthening in multiple intestinal segments in-series

PURPOSE Current models of mechanical intestinal lengthening employ a single device in an isolated segment. Here we demonstrate that polycaprolactone (PCL) springs can be deployed in-series to lengthen multiple intestinal segments simultaneously to further increase overall intestinal length. METHODS A Roux-en-y jejunojejunostomy with a blind Roux limb was created in the proximal jejunum of rats. Two encapsulated 10-mm PCL springs were placed in-series into the Roux limb and were secured with clips. After 4weeks, the lengthened segments were retrieved for histological analyses. RESULTS Lengthening two intestinal segments simultaneously was achieved by placing two PCL springs in-series. The total combined length of the lengthened segments in-series was 45±4mm. The two jejunal segments with PCL springs (25±2 and 20±2mm) were significantly longer than control segments without the spring (14±1mm, p<0.05). CONCLUSION Spring-mediated lengthening can be achieved using multiple springs placed sequentially. The use of the Roux-en-y surgical model allowed easy insertion of springs in a blind Roux limb and arrange them in-series. Combined with relengthening techniques, we can use these methods to increase the length of small intestine to reach clinical significance. LEVEL OF EVIDENCE 1 Experimental.

Nonoperative Management of Appendicitis

We evaluated the outcomes for nonoperative management (NOM) of all children with suspected nonperforated appendicitis, including those patients with an appendicolith. Parents of all children with suspected nonperforated appendicitis were offered NOM versus laparoscopic appendectomy. NOM included administration of intravenous antibiotics and hospital admission. If no improvement within 24 hours, laparoscopic appendectomy was performed. Primary outcomes were initial success rate and recurrence rate. Fifty patients selected NOM. The initial failure rate for NOM was 20%. Of the 10 who failed, 7 had complicated appendicitis. The recurrence rate was 13%. Overall, 34 (68%) patients avoided appendectomy. Patients with an appendicolith had a higher initial failure rate (37%) compared to patients without an appendicolith (10%; P < .05). NOM is feasible and effective in pediatric nonperforated appendicitis. The presence of an appendicolith was associated with a higher failure rate but is not an absolute contraindication for NOM.

Basic fibroblast growth factor eluting microspheres enhance distraction enterogenesis.

PURPOSE The purpose of this study was to determine if distraction enterogenesis using self-expanding polycaprolactone (PCL) springs is a potential therapy for short bowel syndrome. Sustained release basic fibroblast growth factor (bFGF) microspheres have been shown to induce angiogenesis and intestinal regeneration in tissue engineered scaffolds. We hypothesized that the provision of bFGF-loaded microspheres would increase angiogenesis and thereby enhance the process of enterogenesis. METHODS A 10-mm segment of rodent jejunum was isolated and an encapsulated PCL spring inserted. Blank or bFGF-loaded microspheres were delivered to the segment. After 4weeks, jejunal segments were assessed for lengthening, morphology, quantification of blood vessels, and ganglia. RESULTS Lengthened intestinal segments receiving bFGF microspheres demonstrated significantly increased microvascular density compared to those with blank microspheres. There were also significantly more submucosal and myenteric ganglia in the segments that received bFGF microspheres. Segments achieved similar lengthening and final muscular thickness in both blank and bFGF groups, but the bFGF microsphere caused a significant increase in luminal diameter of the jejunal segment. CONCLUSION Sustained release bFGF microspheres enhanced distraction enterogenesis through improved vascularity. The synergy of growth factors such as bFGF with distraction enterogenesis may yield improved results for the future treatment of patients with short bowel syndrome.

Global general pediatric surgery partnership: The UCLA–Mozambique experience

BACKGROUND/PURPOSE There has been increasing recognition of the disparities in surgical care throughout the world. Increasingly, efforts are being made to improve local infrastructure and training of surgeons in low-income settings. The purpose of this study was to review the first 5-years of a global academic pediatric general surgery partnership between UCLA and the Eduardo Mondlane University in Maputo, Mozambique. METHODS A mixed-methods approach was utilized to perform an ongoing needs assessment. A retrospective review of admission and operative logbooks was performed. Partnership activities were summarized. RESULTS The needs assessment identified several challenges including limited operative time, personnel, equipment, and resources. Review of logbooks identified a high frequency of burn admissions and colorectal procedures. Partnership activities focused on providing educational resources, on-site proctoring, training opportunities, and research collaboration. CONCLUSION This study highlights the spectrum of disease and operative case volume of a referral center for general pediatric surgery in sub-Saharan Africa, and it provides a context for academic partnership activities to facilitate training and improve the quality of pediatric general surgical care in limited-resource settings. LEVEL OF EVIDENCE Level IV.