Successful cardiopulmonary resuscitation following minimally invasive pectus excavatum repair: A case report

INTRODUCTION

Pectus excavatum is the most common congenital chest wall deformity. The minimally invasive repair of pectus excavatum (MIRPE) is the most commonly practiced method of surgical treatment and there is concern that the pectus bar will prevent effective CPR. There are no recorded cases of successful cardiopulmonary resuscitation with pectus bars in place.

PRESENTATION OF CASE

A 17-year-old male with pectus excavatum underwent MIRPE. Two years later, he experienced out-of-hospital cardiac arrest and underwent successful cardiopulmonary resuscitation (CPR) in the field with a pectus bar in place.

DISCUSSION

Successful CPR is possible after MIRPE. Clear identification of patients who have undergone MIRPE and education of CPR providers in providing effective chest compressions and defibrillation for this patient population is necessary.

CONCLUSION

This is the first documented case of successful CPR in a patient with a pectus bar in place who experienced out-of-hospital cardiac arrest.

Potentiation of serotonin signaling protects against intestinal ischemia and reperfusion injury in mice

BACKGROUND

Knock-out of serotonin re-uptake transporters (SERT) or use of selective serotonin re-uptake inhibitors (SSRIs) potentiates enteric serotonin (5-HT) signaling and stimulates enterocyte proliferation. We hypothesized that increased serotonin signaling would mitigate epithelial injury from intestinal ischemia and reperfusion (I/R).

METHODS

Mice lacking SERT (SERTKO mice) and wild-type littermates (WTLM) were subjected to intestinal ischemia by superior mesenteric artery (SMA) occlusion. At intervals post-laparotomy with or without ischemia, ileum was harvested and prepared for staining. A WTLM subgroup treated with SSRI after SMA occlusion followed by reperfusion was also sacrificed and analyzed. Mucosal injury was scored, percentage of injured villi calculated, and enterocyte proliferation measured. Lastly, staining for enterocytes, enteroendocrine cells, and goblet cells, villus epithelial cellular make-up was investigated at baseline and 14 days after injury. Measurements were compared between groups using t test and chi-squared test.

KEY RESULTS

Mucosal injury after I/R was significantly decreased in SERTKO and SSRI-treated mice compared to WTLM at all intervals except baseline. Enterocyte proliferation was greater in SERTKO and SSRI-treated mice without alteration in cellular composition along villi (P > 0.05).

CONCLUSIONS AND INFERENCES

Potentiation of 5-HT signaling is associated with mucosal protection from intestinal I/R injury without alterations in villus cell distribution, possibly via increased rates of enterocyte renewal.

Doxycycline sclerotherapy for post-traumatic inguinal lymphocele in a child

Lymphoceles are abnormal collections of lymphatic fluid caused by a disruption in the lymphatic channels and leakage of lymph. This most commonly occurs after surgical procedures, but occasionally lymphoceles may be the result of trauma, more commonly penetrating trauma. Lymphoceles resulting from blunt trauma are rare in both adults and children. In the adult population, there are few published case reports, and management principles vary. To date, there are no reports of traumatic lymphoceles in the paediatric population, and therefore there is no precedent for treatment. Here, we report the case of a young boy who developed an inguinal lymphocele from a bicycle handle bar injury which was successfully treated with doxycycline sclerotherapy.

Localization of muscarinic acetylcholine receptor 2 to the intestinal crypt stem cell compartment

The data presented in this article are related to the research article entitled “Distribution of muscarinic acetylcholine receptor subtypes in the murine small intestine” (E.D. Muise, N. Gandotra, J.J. Tackett, M.C. Bamdad, R.A. Cowles, 2016) [1]. We recently demonstrated that neuronal serotonin stimulates intestinal crypt cell division, and induces villus growth and crypt depth (E.R. Gross, M.D. Gershon, K.G. Margolis, Z.V. Gertsberg, Z. Li, R.A. Cowles, 2012; M.D. Gershon, 2013) [2], [3]. Scopolamine, a nonspecific muscarinic receptor antagonist, inhibited serotonin-induced intestinal mucosal growth [2]. Here we provide data regarding the localization of muscarinic acetylcholine receptor 2 to the intestinal crypt stem cell compartment.

Distribution of muscarinic acetylcholine receptor subtypes in the murine small intestine

AIMS

Serotonin stimulates enterocyte turnover in the small intestine and studies suggest this is mediated by neuronal signaling via a cholinergic pathway. Distribution of the five known muscarinic receptor subtypes (mAChRs) in the small intestine has not been fully studied, and their role in intestinal growth is unknown. We hypothesized that mAChRs have distinct anatomic distributions within the bowel, and that mAChRs present within intestinal crypts mediate the effects of acetylcholine on the small intestinal mucosa.

MAIN METHODS

Small intestine from male C57BL/6 mice ages 2, 4, 6, and 8weeks were harvested. RNA was isolated and cDNA synthesized for PCR-amplification of subtype specific mAChRs. Ileum was fixed with Nakane, embedded in epon, and immunofluorescence microscopy performed using polyclonal antibodies specific to each mAChR1-5.

KEY FINDINGS

All five mAChR subtypes were present in the mouse duodenum, jejunum, and ileum at all ages by RT-PCR. Immunofluorescence microscopy suggested the presence of mAChR1-5 in association with mature enterocytes along the villus and within the myenteric plexus. Only mAChR2 clearly localized to the crypt stem cell compartment, specifically co-localizing with Paneth cells at crypt bases.

SIGNIFICANCE

Muscarinic receptors are widely distributed along the entire alimentary tract. mAChR2 appears to localize to the crypt stem cell compartment, suggesting it is a plausible regulator of stem cell activity. The location of mAChR2 to the crypt makes it a potential therapeutic target for treatment of intestinal disease such as short bowel syndrome. The exact cellular location and action of each mAChR requires further study.

Enhanced serotonin signaling stimulates ordered intestinal mucosal growth

BACKGROUND

Significant quantities of serotonin (5-hydroxytryptamine; 5-HT) are found in the intestine, and studies have demonstrated that 5-HT can stimulate enterocyte cell division, suggesting regulatory roles in mucosal homeostasis and intestinal adaptation. We hypothesized that excess enteric 5-HT signaling enhances mucosal growth without changing intestinal villous cellular makeup.

METHODS

Mice lacking the serotonin reuptake transporter (SERT) and wild-type littermates (WTLM) were euthanized and their ileum analyzed. Villus height (VH), crypt depth (CD), and enterocyte height (EH) were measured. Enterocyte cell division was measured using Ki-67 immunofluorescence to calculate crypt proliferation index (CPI). Cellular distribution along villi was investigated by immunofluorescent staining for enterocytes, enteroendocrine cells, and goblet cells. Group measurements were compared using t-test and chi-squared test.

RESULTS

SERT knock-out (SERTKO) mice had significantly taller villi, deeper crypts, and taller enterocytes compared with WTLM (P < 0.0001). Similarly, enterocyte proliferation was greater in SERTKO compared with WTLM (P < 0.01). For SERTKO, mean values were: VH, 255.6 μm; CD, 66.7 μm; EH, 21.2 μm; and CPI, 52.8%. For WTLM, corresponding values were: VH, 207.8 μm; CD, 56.1 μm; EH, 19.5 μm; and CPI, 31.9%. The cellular composition along villi was not significantly different between genotypes (P > 0.05).

CONCLUSIONS

Enhancing 5-HT signaling in mice increases VH, CD, EH, and crypt cell proliferation in the intestinal mucosa. 5-HT-associated growth did not alter the cellular composition of the villi. Serotonin may represent an important physiologic regulator of intestinal growth and adaptation and holds promise as a target for therapies aimed at enhancing intestinal recovery after injury or mucosal surface area loss.

Accurate assessment of bowel length: the method of measurement matters

PURPOSE

Small intestinal length has prognostic significance for patients with short bowel syndrome, and accurate measurement of Roux-en-Y limbs is considered important. The flexible elasticity of bowel makes its measurement highly subjective, yet a recommended method for intestinal measurement allowing accurate comparisons between surgeons remains undefined. Measurement of intestinal length has been described, but no comparison of the fidelity of measurement technique has been made. We hypothesized that silk suture and umbilical tape would yield the most consistent measurements.

METHODS

This institutional review board-approved prospective trial enrolled 12 volunteer surgeons and two Institutional Animal Care and Use Committee-donated rabbits. Participants were asked to measure short, medium, and long segments of small intestine in a euthanized rabbit using common operating room tools: 18-in silk suture, 75-cm umbilical tape, 15-cm straight ruler, laparoscopic Dorsey bowel graspers. Data were analyzed by analysis of variance repeated measures model.

RESULTS

Over short segments, intestinal measurements by grasper were significantly shorter than those by tape (P = 0.002) and ruler (P = 0.039). Over medium lengths of bowel, measurements by grasper were significantly shorter than those by suture (P = 0.032) and tape (P = 0.046), and measurements by ruler also were significantly shorter than those by suture (P = 0.008). Over the long intestinal segment, measurements by ruler resulted in the greatest variability, and comparison of variance across all possible pairs of groups found significant difference by method of measurement (P = 0.049). There was a significant difference in measurements taken along the mesenteric border compared with those taken along the antimesenteric border (P = 0.001).

CONCLUSIONS

Measurement technique along short segments matters less; however, rigid tools underestimate length, and smaller variances in measurement by silk suture and umbilical tape suggest that these methods are more reliable across longer distances.

Enhanced serotonin signaling increases intestinal neuroplasticity

BACKGROUND

The intestinal mucosa recovers from injury by accelerating enterocyte proliferation resulting in villus growth. A similar phenomenon is seen after massive bowel resection. Serotonin (5-HT) has been implicated as an important regulator of mucosal homeostasis by promoting growth in the epithelium. The impact of 5-HT on other components of growing villi is not known. We hypothesized that 5-HT-stimulated growth in the intestinal epithelium would be associated with growth in other components of the villus such as enteric neural axonal processes.

MATERIALS AND METHODS

Enteric serotonergic signaling is inactivated by the serotonin reuptake transporter, or SERT, molecule. Enhanced serotonin signaling was achieved via SERT knockout (SERTKO) and administration of selective serotonin reuptake inhibitors (SSRI) to wild-type mice (WT-SSRI). 5-HT synthesis inhibition was achieved with administration of 4-chloro-L-phenylalanine (PCPA). Intestinal segments from age-matched WT, SERTKO, WT-SSRI, and corresponding PCPA-treated animals were assessed via villus height, crypt depth, and crypt proliferation. Gap 43, a marker of neuroplasticity, was assessed via immunofluorescence and Western blot.

RESULTS

SERTKO and WT-SSRI mice had taller villi, deeper crypts, and increased enterocyte proliferation compared with WT mice. Gap 43 expression via immunofluorescence was significantly increased in SERTKO and WT-SSRI samples, as well as in Western blot analysis. PCPA-treated SERTKO and WT-SSRI animals demonstrated reversal of 5-HT-induced growth and Gap 43 expression.

CONCLUSIONS

Enhanced 5-HT signaling results in intestinal mucosal growth in both the epithelial cell compartment and the enteric nervous system. Furthermore, 5-HT synthesis inhibition resulted in reversal of effects, suggesting that 5-HT is a critically important regulator of intestinal mucosal growth and neuronal plasticity.

Combining disparate surgical residencies into one: lessons learned

BACKGROUND

Attitudes, career goals, and educational experiences of general surgery residents are profiled during the acquisition of a community residency program by an academic residency program.

MATERIALS AND METHODS

The study population included all general surgery residents postgraduate years 2-5 in a tertiary academic medical center divided into community program matriculants (CPM) or academic program matriculants (APM). A survey compared perceptions before and after residency amalgamation in seven training categories as follows: relationships among residents, relationships with faculty, systems interactions, clinical training, surgical training, scholarship, and career plans. Responses were recorded on a Likert scale. Fisher exact test and one-sided t-test were applied.

RESULTS

Thirty-five trainees (83%) participated, 23 APM (66%) and 12 CPM (34%). Neither cohort reported significant negative perceptions regarding surgical training, career planning, or scholarship (P > 0.05). There was a greater likelihood of significant negative perceptions regarding inter-resident relationships among CPM (P < 0.05). CPM perceived significantly improved opportunities for scholarship (P < 0.01) and nationwide networking through faculty (P < 0.05) after acquisition. There was a nearly significant trend toward CPM perceiving greater access to competitive specialties after acquisition. Overall, CPM perceptions were affected more often after acquisition; however, when affected, APM were less likely to be positively affected (odds ratio, 2.9).

CONCLUSIONS

Acquisition of a community surgery residency by an academic program does not seem to negatively affect trainees' perceptions regarding training. The effect of such acquisition on CPMs' decision to pursue competitive fellowships remains ill defined, but CPM perceived improved research opportunities, faculty networking, and programmatic support to pursue a career in academic surgery.

Malrotation: Current strategies navigating the radiologic diagnosis of a surgical emergency

The most accurate and practical imaging algorithm for the diagnosis of intestinal malrotation can be a complex and sometimes controversial topic. Since 1900, significant advances have been made in the radiographic assessment of infants and children suspected to have anomalies of intestinal rotation. We describe the current methods of abdominal imaging of malrotation along with their pros and cons. When associated with volvulus, malrotation is a true surgical emergency requiring rapid diagnosis and treatment. We emphasize the importance of close cooperation and communication between radiology and surgery to perform an effective and efficient diagnostic evaluation allowing prompt surgical decision making.

First nationwide survey of US integrated 6-year cardiothoracic surgical residency program directors

OBJECTIVE

The recently implemented integrated 6-year (I-6) format represents a significant change in cardiothoracic surgical residency training. We report the results of the first nationwide survey assessing I-6 program directors' impressions of this new format.

METHODS

A 28-question web-based survey was distributed to program directors of all 24 Accreditation Council for Graduate Medical Education-accredited I-6 training programs in November 2013. The response rate was a robust 67%.

RESULTS

Compared with graduates of traditional residencies, most I-6 program directors with enrolled residents believed that their graduates will be better trained (67%), be better prepared for new technological advances (67%), and have superior comprehension of cardiothoracic disease processes (83%). Just as with traditional program graduates, most respondents believed their I-6 graduates would be able to independently perform routine adult cardiac and general thoracic operations (75%) and were equivocal on whether additional specialty training (eg, minimally invasive, heart failure, aortic) was necessary. Most respondents did not believe that less general surgical training disadvantaged I-6 residents in terms of their career (83%); 67% of respondents would have chosen the I-6 format for themselves if given the choice. The greater challenges in training less mature and experienced trainees and vulnerability to attrition were noted as disadvantages of the I-6 format. Most respondents believed that I-6 programs represent a natural evolution toward improved residency training rather than a response to declining interest among medical school graduates.

CONCLUSIONS

High satisfaction rates with the I-6 format were prevalent among I-6 program directors. However, concerns with respect to training relatively less experienced, mature trainees were evident.