Lily V. Saadat

Existing cardiomyocytes generate cardiomyocytes at a low rate after birth in mice

Significance The nature of postnatal cardiomyogenesis in mammals remains in dispute. Here, we provide cell-level evidence for the birth of cardiomyocytes in newborn and adult mice. Our clonal analysis, based on the mosaic analysis with double markers mouse model, shows that cardiomyocytes are the parent cell of origin of cardiomyocytes that are generated postnatally. Our findings confirm that limited, symmetric division of cardiomyocytes is a rare phenomenon in the mouse heart after birth. The mammalian heart has long been considered a postmitotic organ, implying that the total number of cardiomyocytes is set at birth. Analysis of cell division in the mammalian heart is complicated by cardiomyocyte binucleation shortly after birth, which makes it challenging to interpret traditional assays of cell turnover [Laflamme MA, Murray CE (2011) Nature 473(7347):326–335; Bergmann O, et al. (2009) Science 324(5923):98–102]. An elegant multi-isotope imaging-mass spectrometry technique recently calculated the low, discrete rate of cardiomyocyte generation in mice [Senyo SE, et al. (2013) Nature 493(7432):433–436], yet our cellular-level understanding of postnatal cardiomyogenesis remains limited. Herein, we provide a new line of evidence for the differentiated α-myosin heavy chain-expressing cardiomyocyte as the cell of origin of postnatal cardiomyogenesis using the “mosaic analysis with double markers” mouse model. We show limited, life-long, symmetric division of cardiomyocytes as a rare event that is evident in utero but significantly diminishes after the first month of life in mice; daughter cardiomyocytes divide very seldom, which this study is the first to demonstrate, to our knowledge. Furthermore, ligation of the left anterior descending coronary artery, which causes a myocardial infarction in the mosaic analysis with double-marker mice, did not increase the rate of cardiomyocyte division above the basal level for up to 4 wk after the injury. The clonal analysis described here provides direct evidence of postnatal mammalian cardiomyogenesis.

Robotic versus standard laparoscopy for the treatment of endometriosis

OBJECTIVE To compare robot assisted laparoscopic platform to standard laparoscopy for the treatment of endometriosis. DESIGN A retrospective cohort controlled study. SETTING Tertiary referral center. PATIENT(S) Seventy-eight reproductive aged women. INTERVENTION(S) Robot assisted or standard laparoscopy for the treatment of endometriosis between January 2008 and January 2009. MAIN OUTCOME MEASURE(S) Operative time, estimated blood loss, hospitalization time, intraoperative and postoperative complications. RESULT(S) Seventy-eight patients underwent treatment of endometriosis, 40 by robot assisted laparoscopy and 38 by standard laparoscopy. The two groups were matched for age, body mass index (BMI), stage of endometriosis, and previous abdominal surgery. Mean operative time with the robot was 191 minutes (range 135-295 minutes) compared with 159 minutes (range 85-320 minutes) during standard laparoscopy. There were no significant differences in blood loss, hospitalization, intraoperative or postoperative complications. There were no conversions to laparotomy. CONCLUSION(S) Both robot assisted laparoscopic and standard laparoscopic treatment of endometriosis have excellent outcomes. The robotic technique required significantly longer surgical and anesthesia time, as well as larger trocars.

Impact of the 2011 ACGME resident duty hour reform on hospital patient experience and processes-of-care

Introduction In 2011, the Accreditation Council for Graduate Medical Education (ACGME) expanded restrictions on resident duty hours. While studies have shown no association between these restrictions and improved outcomes, process-of-care and patient experience measures may be more sensitive to resident performance, and thus may be impacted by duty hour policies. The objective of this study was to evaluate the association between the 2011 resident duty hour reform and measures of processes-of-care and patient experience. Methods Hospital Consumer Assessment of Healthcare Providers and Systems survey data and process-of-care scores were obtained from the Centers for Medicare and Medicaid Services Hospital Compare website for 1 year prior to (1 July 2010 to 30 June 2011) and 1 year after (1 July 2011 to 30 June 2012) duty hour reform implementation. Using a difference-in-differences model, non-teaching and teaching hospitals were compared before and after the 2011 reform to test the association of this policy with changes in process-of-care and patient experience measure scores. Results Duty hour reform was not associated with a change in the five patient experience measures evaluated, including patients rating a hospital 9 or 10 (coefficient −0.003, 95% CI −0.79 to 0.79) or stating they would ‘definitely recommend’ a hospital (coefficient −0.28, 95% CI −1.01 to 0.44). For all 10 process-of-care measures examined, such as antibiotic timing (coefficient −0.462, 95% CI −1.502 to 0.579) and discontinuation (0.188, 95% CI −0.529 to 0.904), duty hour reform was not associated with a change in scores. Conclusions The 2011 ACGME duty hour reform was not associated with improvements in process-of-care and patient experience measures. These data should be considered when considering reform of resident duty hour policies.

National Surgical Quality Improvement Program analysis of unplanned reoperation in patients undergoing low anterior resection or abdominoperineal resection for rectal cancer

Background: The rate of unplanned reoperation for rectal cancer can provide information about surgical quality. We sought to determine factors associated with unplanned reoperation after low anterior resection and abdominoperineal resection for patients with rectal cancer and outcomes after these reoperations. Methods: The American College of Surgeons National Surgical Quality Improvement Program database was used to conduct this retrospective study. Patients who underwent elective low anterior resection and abdominoperineal resection for rectal cancer from 2012–2014 were identified. The primary outcomes were 30‐day reoperation rates and postoperative complications. Results: A total of 454 low anterior resection patients (5.9%) and 289 abdominoperineal resection patients (8.1%) required reoperation within 30 days of their index operation. The most common reasons for reoperation were infection, bleeding, and bowel obstruction. Multivariate analysis revealed that male sex (odds ratio: 1.5, P = .001), poor functional status (odds ratio: 2.2, P = .04), operative time (odds ratio: 1.001, P = .01), low preoperative albumin (odds ratio: 0.79, P = .04), and lack of ostomy (odds ratio, 0.66, P = .005) were independent risk factors for reoperation after low anterior resection. Smoking (odds ratio: 1.7, P = .001), chronic obstructive pulmonary disease (odds ratio: 1.8, P = .03), poor functional status (odds ratio: 2.1, P = .032), operative time (odds ratio: 1.003, P < .001), low preoperative albumin (odds ratio: 0.69, P = .007), and open approach (odds ratio: 1.5, P = .02) were independent risk factors for reoperation after abdominoperineal resection. Postoperative complication rates are high for those undergoing reoperation, often leading to non‐home discharge (P < .001) after reoperation. Conclusion: Reoperation after low anterior resection and abdominoperineal resection for rectal cancer is not uncommon. This study highlights the indications for reoperation, potentially modifiable preoperative risk factors for reoperation, and the morbidity associated with such operations.

Assessment of the Accuracy of Disease Coding Among Patients Diagnosed With Sarcoma

This case study compares diagnosis codes with pathology reports for patients diagnosed with sarcoma to assess the accuracy of disease coding at a health care center.

Etiology of orbital fractures at a level I trauma center in a large metropolitan city

Background/Purpose: Orbital fractures are a common facial fracture managed by multiple surgical specialties. Methods: A retrospective review of the electronic medical records of patients (age, 18–85 years) presenting to Northwestern Memorial Hospital and Northwestern Medical Faculty Foundation in Chicago, IL, USA with International Classification of Diseases, Ninth Revision codes for facial fractures or CPT (Current Procedural Terminology) codes for orbital fracture repair. Results: A review of the electronic medical records identified 504 individual incidents of orbital fractures with available imaging for review. The most common location for an orbital fracture was a floor fracture (48.0%) followed by a medial wall fracture (25.2%). Left-sided orbital fractures were statistically significantly more common than right-sided orbital fractures (99% confidence interval). Orbital fractures were more prevalent in younger age groups. The mean patient age was 39.3 years. The most common cause of all orbital fractures was assault followed by falls. However, falls were the most common cause of orbital fractures in women and in patients aged 50 years and older. Evaluation by an ophthalmologist occurred in 62.8% of orbital fracture patients, and evaluation by a team comprising the facial trauma service (Otolar-yngology, Plastic Surgery, and Oral and Maxillofacial Surgery) occurred in 81.9% of orbital fracture patients. Conclusion: Assault was the largest cause of all orbital fractures, and occurred most commonly in young males. Assaulted patients were more likely to have left-sided fractures compared to nonassaulted patients. In patients aged 50 years and older, falls were the most common cause of orbital fractures.