Melatonin: an inhibitor of breast cancer

The present review discusses recent work on melatonin-mediated circadian regulation, the metabolic and molecular signaling mechanisms that are involved in human breast cancer growth, and the associated consequences of circadian disruption by exposure to light at night (LEN). The anti-cancer actions of the circadian melatonin signal in human breast cancer cell lines and xenografts heavily involve MT1 receptor-mediated mechanisms. In estrogen receptor alpha (ERα)-positive human breast cancer, melatonin suppresses ERα mRNA expression and ERα transcriptional activity via the MT1 receptor. Melatonin also regulates the transactivation of other members of the nuclear receptor superfamily, estrogen-metabolizing enzymes, and the expression of core clock and clock-related genes. Furthermore, melatonin also suppresses tumor aerobic metabolism (the Warburg effect) and, subsequently, cell-signaling pathways critical to cell proliferation, cell survival, metastasis, and drug resistance. Melatonin demonstrates both cytostatic and cytotoxic activity in breast cancer cells that appears to be cell type-specific. Melatonin also possesses anti-invasive/anti-metastatic actions that involve multiple pathways, including inhibition of p38 MAPK and repression of epithelial-mesenchymal transition (EMT). Studies have demonstrated that melatonin promotes genomic stability by inhibiting the expression of LINE-1 retrotransposons. Finally, research in animal and human models has indicated that LEN-induced disruption of the circadian nocturnal melatonin signal promotes the growth, metabolism, and signaling of human breast cancer and drives breast tumors to endocrine and chemotherapeutic resistance. These data provide the strongest understanding and support of the mechanisms that underpin the epidemiologic demonstration of elevated breast cancer risk in night-shift workers and other individuals who are increasingly exposed to LEN.

Recent advances in solid oxide cell technology for electrolysis

In a world powered by intermittent renewable energy, electrolyzers will play a central role in converting electrical energy into chemical energy, thereby decoupling the production of transport fuels and chemicals from today’s fossil resources and decreasing the reliance on bioenergy. Solid oxide electrolysis cells (SOECs) offer two major advantages over alternative electrolysis technologies. First, their high operating temperatures result in favorable thermodynamics and reaction kinetics, enabling unrivaled conversion efficiencies. Second, SOECs can be thermally integrated with downstream chemical syntheses, such as the production of methanol, dimethyl ether, synthetic fuels, or ammonia. SOEC technology has witnessed tremendous improvements during the past 10 to 15 years and is approaching maturity, driven by advances at the cell, stack, and system levels.

Association of Surgeon Volume With Outcomes and Cost Savings Following Thyroidectomy: A National Forecast

IMPORTANCE

Incidence of thyroidectomies is continuing to increase. Identifying factors associated with favorable outcomes can lead to cost savings.

OBJECTIVE

To assess the association of surgeon volume with clinical outcomes and costs of thyroidectomy.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional analysis performed in October of 2014 of adult (≥ 18 years) inpatients in US community hospitals using the Nationwide Inpatient Sample for the years 2003 through 2009.

EXPOSURES

Thyroidectomy.

MAIN OUTCOMES AND MEASURES

Complications, length of stay, and cost following thyroidectomy in relation to surgeon volume. Surgeon volumes were stratified into low (1-3 thyroidectomies per year), intermediate (4-29 thyroidectomies per year), and high (≥ 30 thyroidectomies per year).

RESULTS

A total of 77,863 patients were included. Procedures performed by low-volume surgeons were associated with a higher risk of postoperative complications compared with high-volume surgeons (15.8% vs 7.7%; OR, 1.55 [95% CI, 1.19-2.03]; P = .001). Mean (SD) hospital cost was significantly associated with surgeon volume (high volume, $6662.69 [$409.31]; intermediate volume, $6912.41 [$137.20]; low volume, $10,396.21 [$345.17]; P < .001). During the study period, if all operations performed by low-volume surgeons had been selectively referred to intermediate- or high-volume surgeons, savings of 11.2% or 12.2%, respectively, would have been incurred. On the basis of the cost growth rate, greater savings are forecasted for high-volume surgeons. With a conservative assumption of 150,000 thyroidectomies per year in the United States, referral of all patients to intermediate- or high-volume surgeons would produce savings of $2.08 billion or $3.11 billion, respectively, over a span of 14 years.

CONCLUSIONS AND RELEVANCE

A surgeon's expertise (measured by surgical volume of procedures per year) is associated with favorable clinical as well as financial outcomes. Our model estimates that considerable cost savings are attainable if higher-volume surgeons perform thyroid procedures in the United States.

Circadian and melatonin disruption by exposure to light at night drives intrinsic resistance to tamoxifen therapy in breast cancer

Resistance to endocrine therapy is a major impediment to successful treatment of breast cancer. Preclinical and clinical evidence links resistance to antiestrogen drugs in breast cancer cells with the overexpression and/or activation of various pro-oncogenic tyrosine kinases. Disruption of circadian rhythms by night shift work or disturbed sleep-wake cycles may lead to an increased risk of breast cancer and other diseases. Moreover, light exposure at night (LEN) suppresses the nocturnal production of melatonin that inhibits breast cancer growth. In this study, we used a rat model of estrogen receptor (ERα(+)) MCF-7 tumor xenografts to demonstrate how altering light/dark cycles with dim LEN (dLEN) speed the development of breast tumors, increasing their metabolism and growth and conferring an intrinsic resistance to tamoxifen therapy. These characteristics were not observed in animals in which the circadian melatonin rhythm was not disrupted, or in animals subjected to dLEN if they received nocturnal melatonin replacement. Strikingly, our results also showed that melatonin acted both as a tumor metabolic inhibitor and a circadian-regulated kinase inhibitor to reestablish the sensitivity of breast tumors to tamoxifen and tumor regression. Together, our findings show how dLEN-mediated disturbances in nocturnal melatonin production can render tumors insensitive to tamoxifen.

Doxorubicin resistance in breast cancer is driven by light at night-induced disruption of the circadian melatonin signal

Chemotherapeutic resistance, particularly to doxorubicin (Dox), represents a major impediment to successfully treating breast cancer and is linked to elevated tumor metabolism and tumor over-expression and/or activation of various families of receptor- and non-receptor-associated tyrosine kinases. Disruption of circadian time structure and suppression of nocturnal melatonin production by dim light exposure at night (dLEN), as occurs with shift work, and/or disturbed sleep-wake cycles, is associated with a significantly increased risk of an array of diseases, including breast cancer. Melatonin inhibits human breast cancer growth via mechanisms that include the suppression of tumor metabolism and inhibition of expression or phospho-activation of the receptor kinases AKT and ERK1/2 and various other kinases and transcription factors. We demonstrate in tissue-isolated estrogen receptor alpha-positive (ERα+) MCF-7 human breast cancer xenografts, grown in nude rats maintained on a light/dark cycle of LD 12:12 in which dLEN is present during the dark phase (suppressed endogenous nocturnal melatonin), a significant shortening of tumor latency-to-onset, increased tumor metabolism and growth, and complete intrinsic resistance to Dox therapy. Conversely, a LD 12:12 dLEN environment incorporating nocturnal melatonin replacement resulted in significantly lengthened tumor latency-to-onset, tumor regression, suppression of nighttime tumor metabolism, and kinase and transcription factor phosphorylation, while Dox sensitivity was completely restored. Melatonin acts as both a tumor metabolic inhibitor and circadian-regulated kinase inhibitor to reestablish the sensitivity of breast tumors to Dox and drive tumor regression, indicating that dLEN-induced circadian disruption of nocturnal melatonin production contributes to a complete loss of tumor sensitivity to Dox chemotherapy.

Melatonin suppression of aerobic glycolysis (Warburg effect), survival signalling and metastasis in human leiomyosarcoma

Leiomyosarcoma (LMS) represents a highly malignant, rare soft tissue sarcoma with high rates of morbidity and mortality. Previously, we demonstrated that tissue-isolated human LMS xenografts perfused in situ are highly sensitive to the direct anticancer effects of physiological nocturnal blood levels of melatonin which inhibited tumour cell proliferative activity, linoleic acid (LA) uptake and metabolism to 13-hydroxyoctadecadienoic acid (13-HODE). Here, we show the effects of low pharmacological blood concentrations of melatonin following oral ingestion of a melatonin supplement by healthy adult human female subjects on tumour proliferative activity, aerobic glycolysis (Warburg effect) and LA metabolic signalling in tissue-isolated LMS xenografts perfused in situ with this blood. Melatonin markedly suppressed aerobic glycolysis and induced a complete inhibition of tumour LA uptake, 13-HODE release, as well as significant reductions in tumour cAMP levels, DNA content and [(3) H]-thymidine incorporation into DNA. Furthermore, melatonin completely suppressed the phospho-activation of ERK 1/2, AKT, GSK3β and NF-kB (p65). The addition of S20928, a nonselective melatonin antagonist, reversed these melatonin inhibitory effects. Moreover, in in vitro cell culture studies, physiological concentrations of melatonin repressed cell proliferation and cell invasion. These results demonstrate that nocturnal melatonin directly inhibited tumour growth and invasion of human LMS via suppression of the Warburg effect, LA uptake and other related signalling mechanisms. An understanding of these novel signalling pathway(s) and their association with aerobic glycolysis and LA metabolism in human LMS may lead to new circadian-based therapies for the prevention and treatment of LMS and potentially other mesenchymally derived solid tumours.

A National Perspective of the Risk, Presentation, and Outcomes of Pediatric Thyroid Cancer

IMPORTANCE

Thyroid cancer is the most common endocrine malignant neoplasm in children and adolescents. Despite a more advanced presentation of thyroid cancer, younger patients tend to have a more favorable prognosis and a lower mortality rate than adults with thyroid cancer.

OBJECTIVE

To examine the presentation and outcomes of thyroid cancer in pediatric patients.

DESIGN, SETTING, AND PARTICIPANTS

A cross-sectional weighted analysis was performed using data from the Nationwide Inpatient Sample from January 1, 2003, to December 31, 2010. Patient data were derived from a sample of 20% of community hospitals in the United States. Six hundred forty-four children and adolescents (age, <18 years; hereinafter referred to as children) with thyroid cancer were compared with 43 536 adults (age, ≥18 years) with thyroid cancer. Data were analyzed from December 7, 2014, to November 19, 2015.

EXPOSURES

Thyroid cancer and thyroidectomy.

MAIN OUTCOMES AND MEASURES

Presentation and management characteristics of thyroid cancer and thyroidectomy outcomes in relation to surgeon volume and specialty.

RESULTS

A total of 644 cases of pediatric thyroid cancer were included (female, 77.3%; mean [SEM] age, 13.8 [0.2] years), corresponding to a weighted sample of 32 563. Compared with adults with thyroid cancer, children were more likely to present with cervical lymph node involvement (31.5% vs 14.7%; odds ratio [OR], 2.29; 95% CI, 1.76-2.97; P < .001) and lung metastases (5.7% vs 2.2%; OR, 2.79; 95% CI, 1.82-4.28; P < .001), whereas bone metastases were more frequent in adults (0.3% vs 1.1%; OR, 0.23; 95% CI, 0.06-0.90; P = .04). Children were more likely to be treated by a low-volume surgeon (26.9% vs 16.0%; OR, 2.09; 95% CI, 1.26-3.48; P = .005) or a pediatric surgeon (14.5% vs 9.6%; OR, 1.66; 95% CI, 1.04-2.67; P = .04) and in a low-volume hospital (20.5% vs 15.2%; OR, 2.97; 95% CI, 1.60-5.54; P < .001) or a teaching hospital (81.7% vs 63.1%; OR, 3.61; 95% CI, 2.33-5.60; P < .001). Compared with those treated by low-volume surgeons, children treated by high-volume surgeons were less likely to experience postoperative complications (14.3% vs 35.9%; OR, 0.16; 95% CI, 0.05-0.51; P = .002) or a hospital stay of more than 1 day (49.8% vs 67.9%; OR, 0.36; 95% CI, 0.15-0.90; P = .03). Management by pediatric surgeons did not significantly alter the risk for postoperative complications compared with other specialties (21.3% vs 18.5%; OR, 1.71; 95% CI, 0.64-4.53, P = .28). Management of thyroid cancer in children was significantly more costly (>$10 067.08/case) compared with adults (P = .04).

CONCLUSIONS AND RELEVANCE

Compared with thyroid cancer in adults, pediatric thyroid cancer is more likely to present as advanced disease and to be managed by low-volume or pediatric surgeons. In addition, within the United States, surgeon volume appears to be more crucial in determining thyroidectomy outcomes than the surgeon's field of specialization.

The safety and efficacy of approaches to liver resection: a meta-analysis

Background:

The aim of this study is to compare the safety and efficacy of conventional laparotomy with those of robotic and laparoscopic approaches to hepatectomy.

Database:

Independent reviewers conducted a systematic review of publications in PubMed and Embase, with searches limited to comparative articles of laparoscopic hepatectomy with either conventional or robotic liver approaches. Outcomes included total operative time, estimated blood loss, length of hospitalization, resection margins, postoperative complications, perioperative mortality rates, and cost measures. Outcome comparisons were calculated using random-effects models to pool estimates of mean net differences or of the relative risk between group outcomes. Forty-nine articles, representing 3702 patients, comprise this analysis: 1901 (51.35%) underwent a laparoscopic approach, 1741 (47.03%) underwent an open approach, and 60 (1.62%) underwent a robotic approach. There was no difference in total operative times, surgical margins, or perioperative mortality rates among groups. Across all outcome measures, laparoscopic and robotic approaches showed no difference. As compared with the minimally invasive groups, patients undergoing laparotomy had a greater estimated blood loss (pooled mean net change, 152.0 mL; 95% confidence interval, 103.3–200.8 mL), a longer length of hospital stay (pooled mean difference, 2.22 days; 95% confidence interval, 1.78–2.66 days), and a higher total complication rate (odds ratio, 0.5; 95% confidence interval, 0.42–0.57).

Conclusion:

Minimally invasive approaches to liver resection are as safe as conventional laparotomy, affording less estimated blood loss, shorter lengths of hospitalization, lower perioperative complication rates, and equitable oncologic integrity and postoperative mortality rates. There was no proven advantage of robotic approaches compared with laparoscopic approaches.

Safety of same-day thyroidectomy: meta-analysis and systematic review

BACKGROUND

Performance of thyroid surgery as a same day surgery procedure has been a controversial topic. This study aimed to compare the safety and efficacy of outpatient thyroid surgery with inpatient thyroid surgery by meta-analysis of current literature.

METHODS

Articles were identified from the following keyword searches: outpatient thyroidectomy/thyroid surgery, same day thyroidectomy/thyroid surgery. Outcomes included perioperative complications including recurrent laryngeal nerve (RLN) injury, hypocalcemia, and readmissions. Data were extracted following review of appropriate studies by authors and random effects models were used.

RESULTS

34 potentially relevant publications were identified and 14 studies fulfilled the predetermined inclusion criteria, totaling 10,478 patients, 4,565 of whom were discharged the same day following thyroid surgery. There was no difference in malignancy rate between the two groups (95% CI, 0.84-2.31; P=0.196). Inpatient group were 2.23 times (95% CI, 1.36-3.36; P=0.001) more likely to develop transient RLN injury and 2.32 times (95% CI, 1.06-5.06; P=0.034) more likely to have documented transient hypocalcemia compared to outpatients. Inpatient groups were 2.10 times (95% CI, 1.33-3.33; P=0.002) more likely to have documented other complications. The two groups also had similar readmission rates (95% CI, 0.71-1.41; P=1.000).

CONCLUSIONS

Our meta-analysis suggests that discharging selective patients the same day after a thyroid surgery is as safe, feasible, and efficacious as admitting them for observation. Admitting patients after thyroid surgery is associated with higher reported risk of complications.

Is vascular flow a predictor of malignant thyroid nodules? A meta-analysis

BACKGROUND

Several reports have proposed that increased vascular flow on color Doppler sonography may be associated with malignancy in thyroid nodules. Others have described no correlation between the presence of flow and risk of malignancy. The purpose of this study was to determine whether the vascularity of a thyroid nodule can aid in the prediction of malignancy by performing a meta-analysis of the current literature.

METHODS

Independent reviewers conducted a systematic review of publications from PubMed, EMBASE, and the Cochrane Database of Systematic Review using the following keyword searches: "vascular thyroid nodule", and "vascular malignant thyroid nodule". Outcomes included vascular flow pattern, nodule size, calcifications, echogenicity, margins, and shape. Data were extracted following review of appropriate studies, and outcome differences were calculated using analysis of variance and the Bonferroni method.

RESULTS

Eighty-nine publications were identified and 14 prospective studies met inclusion criteria totaling 4,154 thyroid nodules, 1,419 (34%) of which were malignant. Thirty-three percent of malignant thyroid nodules had no vascular flow, while 17% had peripheral and 50% had internal vascular flow. There was no significant difference in vascular flow (95% CI: -14.329, 4.257), or peripheral vascular flow rate between malignant and benign thyroid nodules (95% CI: -29.254, 4.313). Also, there was no significant difference in internal vascularity between malignant and benign thyroid nodules (95% CI: -72.067, 2.824).

CONCLUSIONS

It appears that utilization of vascular flow on color Doppler sonography may not accurately predict malignancy in thyroid nodules. Further studies are warranted to investigate the predictive role of increased vascularity in diagnosing suspicious thyroid nodules.

Molecular deficiency (ies) in MT₁ melatonin signaling pathway underlies the melatonin-unresponsive phenotype in MDA-MB-231 human breast cancer cells

Melatonin has been shown repeatedly to inhibit the growth of human breast tumor cells in vitro and in vivo. Its antiproliferative effects have been well studied in MCF-7 human breast cancer cells and several other estrogen receptor α (ERα)-positive human breast cancer cell lines. However, the MDA-MB-231 breast cancer cell line, an ERα-negative cell line widely used in breast cancer research, has been shown to be unresponsive to melatonin's growth-suppressive effect in vitro. Here, we examined the effect of melatonin on the cell proliferation of several ERα-negative breast cancer cell lines including MDA-MB-231, BT-20, and SK-BR-3 cells. Although the MT1 G-protein-coupled receptor is expressed in all three cell lines, melatonin significantly suppressed the proliferation of SK-BR-3 cells without having any significant effect on the growth of MDA-MB-231 and BT-20 cells. We confirmed that the MT1-associated Gα proteins are expressed in MDA-MB-231 cells. Further studies demonstrated that the melatonin unresponsiveness in MDA-MB-231 cells may be caused by aberrant signaling downstream of the Gαi proteins, resulting in differential regulation of ERK1/2 activity.

Hemostatic agent use in thyroid surgery: a meta-analysis

Background

The use of hemostatic agents in thyroid surgery has been widely reported in the literature. The aim of this study is to assess the safety and efficacy of hemostatic agents in comparison to conventional techniques for hemostasis by meta-analysis of the current literature.

Methods

Articles were identified from PubMed and EMBASE using the following keyword searches: "hemostatic agent and thyroid surgery" and "hemostatic agent and thyroidectomy". Outcomes included total operative time, estimated blood loss, length of hospital stay, and intraoperative and postoperative complications. Data were extracted following review of appropriate studies by two independent authors and outcome differences were calculated using analysis of variance and the Bonferroni method.

Results

Thirty-four publications were identified and 10 studies met our inclusion criteria, totaling 941 patients, 519 (55.1%) of which received a hemostatic agent during thyroid surgery. Of these patients who had hemostatic agents, 369 (71%) received a hemostatic gel and 150 (29%) received an oxidized cellulose patch. Outcome measures in each of these groups were compared with the patients receiving only conventional methods of hemostasis. The risk of hematoma formation in the hemostatic gel group was comparable to conventional hemostatic methods (95% CI: 0.33, 2.59). This was also true when comparing conventional hemostasis to the patch (95% CI: 0.64, 15.24). No difference in the risk for seroma formation was found between the conventional and hemostatic gel groups (95% CI: 0.26, 3.95). Drain output was significantly less in the gel group 40.75±35.6 mL compared to 66.26±31.2 mL in the conventional group (95% CI: -23.422, -7.460). Patients who received hemostatic agents had shorter hospital stays when compared to the conventional group (95% CI: -1.057, -0.203).

Conclusions

Our meta-analysis suggests that the use of a hemostatic agent in thyroid surgery yields minimal advantages for the management of perioperative bleeding risk.

The effect of race and socioeconomic status on outcomes following adrenal operations

BACKGROUND

Disparities following different operations exist. We seek to measure the effects of race/ethnicity and socioeconomic status on outcomes following adrenal surgery.

METHODS

Cross-sectional analysis of adrenal operations identified in the Nationwide Inpatient Sample (NIS) from 2003 to 2009.

RESULTS

A total of 7,537 procedures were included. Operations by high-volume surgeons had shorter length of stay (LOS) (3.4 days vs. 5.2 days, P < 0.001) and fewer complications (11.6% vs. 16.7%, P < 0.001). Hispanics were more likely to be operated on by low-volume surgeons [OR: 2.17, 95%CI: (1.33, 3.55)]. There were significant differences in LOS and cost among races/ethnicities, income categories, and insurance types (P < 0.05). Hispanics had longer LOS compared to Whites (P = 0.002) and their management was associated with a higher cost ($20,754.00 ± 1,478.40). Patients with either Medicaid [OR: 1.70, 95%CI: (1.30, 2.22)] or Medicare [OR: 1.86, 95%CI: (1.36, 2.54)] were more likely to have a LOS >5 days.

CONCLUSIONS

Racial and socioeconomic disparities exist; however, they are not solely related to access. A complex interplay between various racial, cultural, and socioeconomic factors likely influence outcomes in adrenal surgery.

The Impact of In-house Attending Surgeon Supervision on the Rates of Preventable and Potentially Preventable Complications and Death at the Start of the New Academic Year

The purpose of this study was to examine the impact of in-house attending surgeon supervision on the rate of preventable deaths (PD) and complications (PC) at the beginning of the academic year. All trauma patients admitted to the Los Angeles County 1 University of Southern California Medical Center over an 8-year period ending in December 2009 were reviewed. Morbidity and mortality reports were used to extract all PD/PC. Patients admitted in the first 2 months (July/ August) of the academic year were compared with those admitted at the end of the year (May/June) for two distinct time periods: 2002 to 2006 (before in-house attending surgeon supervision) and 2007 to 2009 (after 24-hour/day in-house attending surgeon supervision). During 2002 to 2006, patients admitted at the beginning of the year had significantly higher rates of PC (1.1% for July/ August vs 0.6% for May/June; adjusted odds ratio [OR], 1.9; 95% confidence interval [CI], 1.1 to 3.2; P < 0.001). There was no significant difference in mortality (6.5% for July/August vs 4.6% for May/ June; adjusted OR, 1.1; 95% CI,0.8 to 1.5; P = 0.179). During 2007 to 2009, after institution of 24-hour/day in-house attending surgeon supervision of fellows and housestaff, there was no significant difference in the rates of PC (0.7% for July/August vs 0.6% for May/June; OR, 1.1; 95% CI, 0.8 to 1.3; P = 0.870) or PD (4.6% for July/August vs 3.7% for May/June; OR, 1.3; 95% CI, 0.9 to 1.7; P = 0.250) seen at the beginning of the academic year. At an academic Level I trauma center, the institution of 24-hour/day in-house attending surgeon supervision significantly reduced the spike of preventable complications previously seen at the beginning of the academic year.

Retinal dialysis and detachment in a child after airbag deployment

A variety of airbag-associated ocular injuries have been reported in children sitting in the front passenger seat during automobile collisions. These injuries range from corneal abrasions to traumatic hyphema with secondary glaucoma and cataract. We report the case of a 5-year-old boy who experienced retinal dialysis and detachment associated with airbag deployment. The patient recovered 20/20 visual acuity after cryopexy and placement of a radial sponge.

Dark hypopyon in Streptococcus bovis endogenous endophthalmitis: clinicopathologic correlations

Purpose

The aim of this report is to present a previously unreported causative organism associated with brown-pigmented hypopyon in a patient with endophthalmitis.

Methods

This is a retrospective case report which includes clinicopathologic correlations.

Results

Vitreous cultures demonstrated Streptococcus bovis infection resulting in a brown-pigmented hypopyon, with uveal pigment found intra- and extracellularly on pathologic examination of the pupillary membrane.

Conclusions

S. bovis endophthalmitis may be a cause of dark hypopyon, especially in patients with a history of liver disease, and, when identified, warrants colonoscopy and cardiac workup.

Long-Term Outcomes in Complex Abdominal Wall Reconstruction Repaired With Absorbable Biologic Polymer Scaffold (Poly-4-Hydroxybutyrate)

Introduction

After promising early outcomes in the use of absorbable biologic mesh for complex abdominal wall reconstruction, significant criticism has been raised over the longevity of these repairs after its 2-year resorption profile.

Methods

This is the long-term (5-year) follow-up analysis of our initial experience with the absorbable polymer scaffold poly-4-hydroxybutyrate (P4HB) mesh compared with a consecutive contiguous group treated with porcine cadaveric mesh for complex abdominal wall reconstructions. Our clinical analysis was performed using Stata 14.2 and Excel 16.16.23.

Results

After a 5-year follow-up period, the P4HB group (n = 31) experienced lower rates of reherniation (12.9% vs 38.1%; P = 0.017) compared with the porcine cadaveric mesh group (n = 42). The median interval in months to recurrent herniation was similar between groups (24.3 vs 20.8; P = 0.700). Multivariate logistic regression analysis on long-term outcomes identified smoking (P = 0.004), African American race (P = 0.004), and the use of cadaveric grafts (P = 0.003) as risks for complication while smoking (P = 0.034) and the use of cadaveric grafts (P = 0.014) were identified as risks for recurrence. The long-term cost analysis showed that P4HB had a $10,595 per case costs savings over porcine cadaveric mesh.

Conclusions

Our study identified the superior outcomes in clinical performance and a value-based benefit of absorbable biologic P4HB scaffold persisted after the 2-year resorption timeframe. Data analysis also confirmed the use of porcine cadaveric grafts independently contributed to the incidence of complications and recurrences.

Rectovaginal Fistula Repair 1 Year Later: Lessons Learned

INTRODUCTION

Rectovaginal (RV) fistulas are notoriously difficult to treat. Various methods for repair exist, and refinements in techniques can lead to "successful" outcomes. Review of the literature demonstrates that outcomes studies are scarce and mostly limited to comments on closure rate. We have experienced "success" in our own series with 100% closure rate, regardless of fistula etiology and comorbidities (radiation, inflammation, etc). However, long-term outcomes, including various complications and quality of life changes, have previously been underreported.

METHODS

Critical analysis of various outcomes after fistula repair in 14 patients was performed. Patients were surveyed and interviewed with regard to problems before and after fistula repair to obtain objective data focusing on their experience and outcomes. Conclusions are based on physician assessment and patient surveys 1 year after fistula repair and at least 6 months after ostomy reversal and are discussed within the context of data from the literature.

RESULTS

Overall satisfaction rate after repairs was high. All patients would undergo attempt at repair again regardless of complications or functional changes (not present before repair). After repair, sexual dyspareunia affected 5 patients (36%); however, most abstained from sexual activity when their RV fistula became apparent. No patient admitted to dyspareunia before the development of their RV fistula. Anal sphincter and defecation function, as well as stool continence, were judged by surgeons and patients uniformly as adequate. However, 3 patients (21%) complained of intermittent problems with urination. A new/different type of pain affected 2 of 4 patients with Crohn disease. One of these patients subsequently developed a new postsphincteric RV fistula. Another patient noted new intermittent vaginal discharge after ostomy reversal, and magnetic resonance imaging suggested a residual fistula, which was not seen on follow-up sigmoidoscopy and "Blue Dye Test."

CONCLUSIONS

We previously reported on algorithms for repair and refinements in techniques for "successful" repair of RV fistulas with zero recurrence rate. Long-term follow-up indicates, however, that although the overall satisfaction rate after surgery is high, true "success," defined as permanent fistula closure, is not necessarily problem free. Long-term morbidity and the management of other unique sequelae and problems are underreported.