Gastroparesis after lung transplantation. Potential role in postoperative respiratory complications

Gastrointestinal complications in pediatric lung transplant recipients: Incidence, risk factors, and effects on patient outcomes

BACKGROUND

Gastrointestinal (GI) complications in lung transplant recipients can occur any time during the post-operative period, leading to prolonged morbidity and mortality. Despite the negative association between GI complications and patient outcomes, little is known about their incidence and risk factors for their development in pediatric lung transplant recipients.

METHODS

We performed a retrospective chart review at one pediatric tertiary center to describe the frequency of GI complications in lung transplant recipients. We identified potential risk factors for the diagnosis of gastroparesis, gastroesophageal reflux disease (GERD) and aspiration in the post-transplant period. Lastly, we investigated the association of these complications with mortality and graft survival.

RESULTS

84.3% of lung transplant recipients experienced at least one GI complication in the post-transplant period. Gastroparesis (52.9%), GERD (41.2%), and oropharyngeal dysphagia/laryngeal penetration (33.3%) were the most common complications diagnosed. Post-operative opioid exposure was a risk factor for gastroparesis, with the odds increasing 3.0% each day a patient was prescribed opioids (p = .021). The risk of death or retransplant in individuals who experienced gastroparesis was 2.7 times higher than those not diagnosed with gastroparesis (p = .027).

CONCLUSION

Exposure to opioids in the post-operative period is a risk factor for gastroparesis and a prolonged hospitalization placed patients at risk for aspiration. Gastroparesis was associated with increased patient mortality and graft failure, while aspiration and GERD had no effect on long term outcomes. Future prospective studies investigating the relationship between opioid use and the development of a gastroparesis are necessary to improve patient outcomes.

Efficacy and safety of gastric per-oral endoscopic myotomy (GPOEM) in lung transplant patients with refractory gastroparesis: a systematic review and meta-analysis

BACKGROUND

Post-lung transplant gastroparesis is a frequent debilitating complication of lung transplant recipients, as it can increase the risk for gastro-esophageal reflux disease and subsequent graft dysfunction. We performed a systematic review and meta-analysis to evaluate the efficacy and safety of GPOEM in lung transplant patients with refractory gastroparesis.

METHODS

The present systematic review and meta-analysis wer performed according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. We selected studies that analyzed the gastroparesis cardinal symptom index (GCSI) before and after the procedure to verify the efficacy of GPOEM. Random-effects model was used and the analysis was performed with STATA 17.

RESULTS

Four observational studies (one conference abstract) with 104 patients were included in the meta-analysis. Prior treatments for gastroparesis included prokinetic agents and botulinum toxin in 78% (78/104) and 66.7% (66/99), respectively. Pooled estimate for clinical efficacy of GPOEM was 83% (95% CI 76%-90%). The pooled mean reduction in GCSI following the procedure was - 2.01 (- 2.35, - 1.65, p = 0.014). Three studies reported statistically significant improvement of gastro-esophageal retention or emptying in the post-GPOEM period. 30-day post-operative complications included minor or major bleeding (11.6%), severe reflux (1.2%), and pyloric stenosis (1.2%) requiring re-intervention. 90-day all-cause mortality was 2.6% with one patient dying from severe allograft rejection.

CONCLUSION

Our study showed that GPOEM is an effective and safe strategy for lung transplant patients with refractory gastroparesis and should be considered as a therapeutic strategy in this population. Larger multicenter trials are needed in the future to further evaluate the effect of GPOEM on allograft function and rates of rejection.

It cuts both ways: A single-center retrospective review describing a three-way interaction between flucloxacillin, voriconazole and tacrolimus

AIM

Tacrolimus is a CYP3A4 substrate with a narrow therapeutic index that requires dose adjustment when used with voriconazole, a recognized CYP3A4 inhibitor. Interactions involving flucloxacillin and tacrolimus or voriconazole individually have been shown to result in decreased concentrations of the latter two drugs. Tacrolimus concentrations have been reported to be unaffected by flucloxacillin when voriconazole is administered; however, this has not been extensively investigated.

METHODS

Retrospective review of voriconazole and tacrolimus concentrations and subsequent dose adjustment following flucloxacillin administration.

RESULTS

Eight transplant recipients (five lung, two re-do lung, one heart) received concurrent flucloxacillin, voriconazole and tacrolimus. Voriconazole trough concentrations were measured before flucloxacillin initiation in three of eight patients and all trough concentrations were therapeutic. Following flucloxacillin initiation, all eight patients exhibited subtherapeutic concentrations of voriconazole (median concentration 0.15 mg/L [interquartile range (IQR) 0.10-0.28]). In five patients, voriconazole concentrations remained subtherapeutic despite dose increases, and treatment for two patients was changed to alternative antifungal agents. All eight patients required tacrolimus dose increases to maintain therapeutic concentrations after flucloxacillin initiation. Median total daily dose prior to flucloxacillin treatment was 3.5 mg [IQR 2.0-4.3] and this increased to 13.5 mg [IQR 9.5-20] (P=0.0026) during flucloxacillin treatment. When flucloxacillin was ceased, the median tacrolimus total daily dose reduced to 2.2 mg [IQR 1.9-4.7]. Supra-therapeutic tacrolimus concentrations were observed in seven patients after flucloxacillin discontinuation (median concentration 19.7 μg/L [IQR 17.9-28.0]).

CONCLUSION

A significant three-way interaction was shown between flucloxacillin, voriconazole and tacrolimus, resulting in subtherapeutic voriconazole concentrations, and requiring substantial tacrolimus dose increases. Administration of flucloxacillin to patients receiving voriconazole should be avoided. Tacrolimus concentrations should be closely monitored, and dosing adjusted during and after flucloxacillin administration.

Invasive acupuncture for gastroparesis after thoracic or abdominal surgery: a systematic review and meta-analysis

OBJECTIVES

This meta-analysis aimed to systematically evaluate the efficacy of acupuncture in treating postsurgical gastroparesis syndrome (PGS) after thoracic or abdominal surgery.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Twelve databases (PubMed, Embase, Cochrane Library Cochrane Central Register of Controlled Trials (CENTRAL), Medline (Ovid) (from 1946), Web of Science, EBSCO, Scopus, Open Grey, China National Knowledge Infrastructure (CNKI), Wanfang Database, Chinese Scientific Journals Database (VIP) and China Biology Medicine disc (CBM)) and three registration websites (WHO International Clinical Trials Registry Platform (ICTRP), ClinicalTrials.gov, and Chinese Clinical Trial Registry (ChiCTR)) were searched from the inception to September 2022, and citations of the included literature were screened.

ELIGIBILITY CRITERIA

All randomised controlled trials addressing invasive acupuncture for PGS.

DATA EXTRACTION AND SYNTHESIS

Key information on the included studies was extracted by two reviewers independently. Risk ratio (RR) with 95% CI was used for categorical data, and mean difference with 95% CI for continuous data. The quality of evidence was assessed using Grading of Recommendations Assessment, Development and Evaluation. Outcomes were conducted with trial sequential analysis (TSA).

RESULTS

Fifteen studies with 759 patients met the inclusion criteria. Subgroup analyses revealed that compared with the drug group, the drug and acupuncture group had a greater positive effect on the total effective rate (TER) (nine trials, n=427; RR=1.20; 95% CI 1.08 to 1.32; P-heterogeneity=0.20, I2=28%, p=0.0004) and the recovery rate (RCR) (six trials, n = 294; RR = 1.61; 95% CI 1.30 to 1.98; P-heterogeneity=0.29, I2=19%, p<0.0001) of PGS after abdominal surgery. However, acupuncture showed no significant advantages in terms of the TER after thoracic surgery (one trial, p=0.13) or thoracic/abdominal surgery-related PGS (two trials, n = 115; RR=1.18; 95% CI 0.89 to 1.57; P-heterogeneity=0.08, I2=67%, p=0.24) and the RCR after thoracic/abdominal surgery (two trials, n=115; RR=1.40; 95% CI 0.97 to 2.01; P-heterogeneity=0.96, I2=0%, p=0.07). The quality of evidence for TER and RCR was moderate certainty. Only one study reported an acupuncture-related adverse event, in the form of mild local subcutaneous haemorrhage and pain that recovered spontaneously. TSA indicated that outcomes reached a necessary effect size except for clinical symptom score.

CONCLUSION

Based on subgroup analysis, compared with the drug treatment, acupuncture combined drug has significant advantages in the treatment of PGS associated with abdominal surgery, but not with thoracic surgery.

PROSPERO REGISTRATION NUMBER

CRD42022299189.

Application of Physiologically Based Pharmacokinetic Modeling to Predict Drug-Drug Interactions between Elexacaftor/Tezacaftor/Ivacaftor and Tacrolimus in Lung Transplant Recipients

Elexacaftor/tezacaftor/ivacaftor (ETI) treatment has potential benefits in lung transplant recipients, including improvements in extrapulmonary manifestations, such as gastrointestinal and sinus disease; however, ivacaftor is an inhibitor of cytochrome P450 3A (CYP3A) and may, therefore, pose a risk for elevated systemic exposure to tacrolimus. The aim of this investigation is to determine the impact of ETI on tacrolimus exposure and devise an appropriate dosing regimen to manage the risk of this drug-drug interaction (DDI). The CYP3A-mediated DDI of ivacaftor-tacrolimus was evaluated using a physiologically based pharmacokinetic (PBPK) modeling approach, incorporating CYP3A4 inhibition parameters of ivacaftor and in vitro enzyme kinetic parameters of tacrolimus. To further support the findings in PBPK modeling, we present a case series of lung transplant patients who received both ETI and tacrolimus. We predicted a 2.36-fold increase in tacrolimus exposure when co-administered with ivacaftor, which would require a 50% dose reduction of tacrolimus upon initiation of ETI treatment to avoid the risk of elevated systemic exposure. Clinical cases (N = 13) indicate a median 32% (IQR: -14.30, 63.80) increase in the dose-normalized tacrolimus trough level (trough concentration/weight-normalized daily dose) after starting ETI. These results indicate that the concomitant administration of tacrolimus and ETI may lead to a clinically significant DDI, requiring the dose adjustment of tacrolimus.

Risk Factors and Outcomes for Gastroparesis After Lung Transplantation

BACKGROUND

Gastroparesis is common after lung transplantation and is associated with worse transplant outcomes, including the development of chronic lung allograft dysfunction (CLAD). This study sought to identify the prevalence, risk factors, and outcomes associated with a new diagnosis of gastroparesis after lung transplantation.

METHODS

This was a single-center retrospective study of patients who underwent lung transplantation in 2008-2018. The primary outcome was a new diagnosis of gastroparesis within 3 years of transplant. Secondary outcomes included a new diagnosis of gastroesophageal reflux and the association between gastroparesis and both post-transplant survival and CLAD-free survival. Multivariable logistic regression was used to compare diagnosis of gastroparesis and gastroesophageal reflux, while multivariable Cox proportional hazards models were used to analyze gastroparesis and post-transplant outcomes.

RESULTS

Of 616 patients with no prior history of gastroparesis, 107 (17.4%) were diagnosed with delayed gastric emptying within 3 years of transplant. On multivariable logistic regression, black race (OR 2.16, 95% CI 1.18-3.98, p = 0.013) was significantly associated with a new diagnosis of gastroparesis. Age, sex, history of diabetes, connective tissue disease, type of transplant, diagnosis group, renal function, and body mass index were not predictive of gastroparesis post-transplant. Gastroparesis was significantly associated with CLAD (HR 1.76, 95% CI 1.20-2.59, p = 0.004), but not with overall mortality (HR 1.16, p = 0.43).

CONCLUSION

While gastroparesis is common after lung transplantation, it remains difficult to predict which patients will develop these complications post-transplant. Black patients were more likely to be diagnosed with gastroparesis after adjusting for relevant confounders. Gastroparesis is associated with increased risk of CLAD, and further studies are needed to assess whether early detection and treatment can reduce the incidence of CLAD.

Role of gastric per-oral endoscopic myotomy (G-POEM) in post-lung transplant patients: a multicenter experience

Background and study aims  Gastroparesis post-lung transplant (LTx) can lead to increased risk of gastroesophageal reflux (GER) and accelerated graft dysfunction. We aimed to evaluate the efficacy and safety of gastric per-oral endoscopic myotomy (G-POEM), a promising tool in patients with refractory gastroparesis, for managing refractory gastroparesis and GER in post-LTx patients. Patents and methods  This was a multicenter retrospective study on post-LTx patients who underwent G-POEM for management of gastroparesis and GER that were refractory to standard medical therapy. The primary outcome was clinical success post-G-POEM. Secondary outcomes included the rate of post-G-POEM objective esophageal pH exam normalization, rate of gastric emptying scintigraphy (GES) normalization, technical success, and adverse events. Results  A total of 20 patients (mean age 54.7 ± 14.1 years, Female 50 %) underwent G-POEM at a median time of 13 months (interquartile range 6.5-13.5) post-LTx. All G-POEM procedures were technically successful. Clinical success was achieved in 17 (85 %) patients during a median follow-up time of 8.9 (IQR: 3-17) months post-G-POEM. Overall GCSI and two of its subscales (bloating and postprandial fullness/early satiety) improved significantly following G-POEM. Two patients (10 %) developed post-procedural AEs (delayed bleeding 1, pyloric stenosis 1, both moderate in severity). Post-G-POEM GES improvement was achieved in 12 of 16 patients (75 %). All 20 patients were on proton pump inhibitors pre-G-POEM, as opposed to five post-G-POEM. Post-G-POEM PH study normalization was noted in nine of 10 patients (90 %) who underwent both pre- and post-G-poem pH testing. Conclusions  G-POEM is a promising noninvasive therapeutic tool for management of refractory gastroparesis and GER post-LTx.

Delayed Gastric Emptying in Prelung Transplant Patients Is Associated With Posttransplant Acute Cellular Rejection Independent of Reflux

GOAL

The goal of this study was to evaluate the relationship between pretransplant delayed gastric emptying (DGE) and posttransplant acute cellular rejection (ACR) in lung transplant recipients.

BACKGROUND

DGE is very prevalent (23% to 91%) after lung transplantation but pretransplant prevalence has not been well studied. DGE may lead to poor posttransplant outcomes by predisposing to microaspiration. Pretransplant testing for DGE may help identify patients at risk for negative posttransplant outcomes including ACR.

MATERIALS AND METHODS

A retrospective review of a prospectively collected database of consecutive patients undergoing prelung transplant evaluation at a tertiary referral center from 2010 to 2015 was performed. Patients with pretransplant gastric emptying scintigraphy were included in the study. ACR diagnosis was made using International Society for Heart and Lung Transplantation (ISHLT) histologic criteria. Typical gastroparesis symptoms at the time of gastric emptying scintigraphy and pretransplant 24-hour pH impedance monitoring (MII-pH) data was collected. Logistic regression was used for multivariate analysis. Subgroup analyses were performed to account for gastroesophageal reflux (GER).

RESULTS

A total of 83 subjects (18 with DGE, 51.8% male, mean age: 53.6 y) met the criteria for inclusion. Patients with DGE were more likely to have typical symptoms of gastroparesis, though 61.1% of DGE patients were asymptomatic. ACR was more prevalent in patients with DGE (33.3% vs. 12.3%, P=0.04). This correlation was independent of GER as measured by MII-pH on subgroup analysis (75% vs. 14.3%, n=0.02).

DISCUSSION

Lung transplant recipients with pretransplant DGE have a higher incidence of ACR, independent of GER. Routine pretransplant testing for DGE may help identify patients at greater risk for adverse posttransplant outcomes as the majority of patients with DGE are asymptomatic.

Swallowing and laryngeal complications in lung and heart transplantation: Etiologies and diagnosis

Despite continued surgical advancements in the field of cardiothoracic transplantation, post-operative complications remain a burden for the patient and the multidisciplinary team. Lesser-known complications including swallowing disorders (dysphagia), and voice disorders (dysphonia), are now being reported. Such disorders are known to be associated with increased morbidity and mortality in other medical populations, however their etiology amongst the heart and lung transplant populations has received little attention in the literature. This paper explores the potential mechanisms of oropharyngeal dysphagia and dysphonia following transplantation and discusses optimal modalities of diagnostic evaluation and management. A greater understanding of the implications of swallowing and laryngeal dysfunction in the heart and lung transplant populations is important to expedite early diagnosis and management in order to optimize patient outcomes, minimize allograft injury and improve quality of life.

Gastric peroral endoscopic myotomy (GPOEM) for severe gastroparesis after lung transplantation: A promising minimally invasive option

BACKGROUND

After lung transplantation (LT), gastroparesis is frequent, occurring in 25-63% of cases and leading to pulmonary infections. In refractory disease, classical management has demonstrated limited efficacy. Gastric peroral endoscopic myotomy (G-POEM) is a recently developed safe and effective procedure that has been performed here on five patients with severe post-LT gastroparesis.

METHODS

In all patients, the diagnosis was confirmed by disturbed gastric emptying scintigraphy and GCSI calculation showing severe disease. Upper gastrointestinal endoscopies confirmed the absence of organic lesions. All patients were informed about the procedure and signed informed consent forms. The procedure consisted of performing an endoscopic pyloromyotomy under general anesthesia.

RESULTS

The patients were between 35 and 64 years of age. Four had chronic disease, starting approximately 1 year following LT, and one had acute, severe gastroparesis requiring intubation in the intensive care unit. All patients underwent G-POEM after failure of medical treatment, without any complications. Three of the patients with chronic disease improved; they resumed a normal diet and gained weight. The patient with acute disease was discharged within a few days following the procedure and resumed oral intake.

CONCLUSION

G-POEM is promising for managing post-LT refractory gastroparesis and should be further evaluated.

Early postoperative complications in lung transplant recipients

Lung transplantation has become an established therapy for end-stage lung diseases. Early postoperative complications can impact immediate, mid-term, and long-term outcomes. Appropriate management, prevention, and early detection of these early postoperative complications can improve the overall transplant course. In this review, we highlight the incidence, detection, and management of these early postoperative complications in lung transplant recipients.

Systemic Disease Associations with Disorders of Gut-Brain Interaction and Gastrointestinal Transit: A Review

Functional gastrointestinal disorders (FGID) are now classified within the Rome IV framework as disorders of gut-brain interaction (DGBI). Disorders of gastrointestinal transit (as defined by abnormalities on contemporary gastrointestinal motility testing) frequently are associated with symptoms that are also characteristic of DGBIs. In this narrative review, we outline a non-inclusive set of systemic diseases or risk factors that have been classically associated with DGBIs and disorders of gastrointestinal transit; these include diabetes mellitus, paraneoplastic syndromes, surgery, Parkinson's disease, systemic sclerosis, endocrinopathies, polypharmacy, and post-infectious syndromes.

Safe Use of Erythromycin For Refractory Gastroparesis After Small Bowel Transplantation

Current therapeutic options with prokinetic agents for posttransplant gastroparesis are limited. Erythromycin is associated with adverse reactions, including corrected QT interval prolongation and cytochrome P450 3A4 isoenzyme inhibition. The use of erythromycin has been avoided in patients undergoing treatment with cyclosporine or tacrolimus because of significant fluctuations in therapeutic immunosuppression levels. We report herein the successful use of erythromycin after visceral transplant to treat delayed gastric emptying. Two patients were managed with oral erythromycin (initial dose of 750 mg/d divided into 3 doses) for gastroparesis after visceral transplant. Patient 1 was a woman aged 42 years with a history of chronic intestinal pseudo-obstruction syndrome who underwent isolated small bowel transplant with dual (gastric and duodenal) proximal allograft anastomosis. Posttransplant gastroparesis was initially managed with oral metoclopramide. The patient also required high doses of tacrolimus (36 mg/d) to maintain adequate immunosuppression levels. The decision was made to change metoclopramide to erythromycin, which significantly decreased the daily tacrolimus dose requirement (from 36 to 9 mg/d), with resolution of nausea and intermittent bloating symptoms. Patient 2 was a woman aged 35 years with ultra-short gut syndrome after extensive enterectomy due to intestinal volvulus who underwent uneventful combined intestinal and colon transplant. Conventional pharmacologic therapy for gastroparesis was initiated after surgery without success. Erythromycin was started 15 days posttransplant, with significant improvement in her symptoms, and discontinued 47 days post-transplant. To maintain therapeutic levels (8-10 mg/dL), daily tacrolimus dose was decreased 75.8% and 36.5% for patients 1 and 2, respectively. No significant side effects associated with erythromycin use were observed in either patient. Our findings here suggest that erythromycin may be safely used for gastroparesis after small bowel transplant. Close monitoring of immunosuppressive drug levels and dose adjustments of other medications affected by inhibition of cytochrome P450 3A4 are advised.

Metoclopramide Reduces Fluoroscopy and Procedure Time during Gastrojejunostomy Tube Placement: A Placebo-Controlled Trial

PURPOSE

To determine whether a single 10-mg intravenous dose of the promotility agent metoclopramide reduces the fluoroscopy time, radiation dose, and procedure time required for gastrojejunostomy (GJ) tube placement.

METHODS

This prospective, randomized, double-blind, placebo-controlled trial enrolled consecutive patients who underwent primary GJ tube placement at a single institution from April 10, 2018, to October 3, 2019. Exclusion criteria included age less than 18 years, inability to obtain consent, metoclopramide allergy or contraindication, and altered pyloric anatomy. Average fluoroscopy times, radiation doses, and procedure times were compared using t-tests. The full study protocol can be found at www.clinicaltrials.gov (NCT03331965).

RESULTS

Of 110 participants randomized 1:1, 45 received metoclopramide and 51 received placebo and underwent GJ tube placement (38 females and 58 males; mean age, 55 ± 18 years). Demographics of the metoclopramide and placebo groups were similar. The fluoroscopy time required to advance a guide wire through the pylorus averaged 1.6 minutes (range, 0.3-10.1 minutes) in the metoclopramide group versus 4.1 minutes (range, 0.2-27.3 minutes) in the placebo group (P = .002). Total procedure fluoroscopy time averaged 5.8 minutes (range, 1.5-16.2 minutes) for the metoclopramide group versus 8.8 minutes (range, 2.8-29.7 minutes) for the placebo group (P = .002). Air kerma averaged 91 mGy (range, 13-354 mGy) for the metoclopramide group versus 130 mGy (range, 24-525 mGy) for the placebo group (P = .04). Total procedure time averaged 16.4 minutes (range, 8-51 minutes) for the metoclopramide group versus 19.9 minutes (range, 6-53 minutes) for the placebo group (P = .04). There were no drug-related adverse events and no significant differences in procedure-related complications.

CONCLUSIONS

A single dose of metoclopramide reduced fluoroscopy time by 34%, radiation dose by 30%, and procedure time by 17% during GJ tube placement.

Gastroesophageal Reflux and Microaspiration in Lung Transplant Recipients: The Utility of a Single Esophageal Manometry and pH Probe Monitoring Study

BACKGROUND

Gastroesophageal reflux (GER) in recipients of lung transplant (LTX) is associated with chronic allograft rejection, presumably via microaspiration that damages airway epithelium. Most LTX programs perform a single post-LTX esophageal study to evaluate for GER; the efficacy of this test is unclear.

METHODS

Patients with 1 year of post-LTX follow-up, including routine bronchoscopies with bronchoalveolar lavage fluid (BALF) samples as well as high-resolution esophageal manometry and pH probe monitoring (HREMpH), were evaluated. BALF samples were analyzed with competitive enzyme-linked immunosorbent assay to detect bile salts, which are indicative of aspiration. These results were compared to results of HREMpH studies post LTX.

RESULTS

Ninety BALF samples were analyzed for bile salts and acted as disease positive for this evaluation. Of the 13 HREMpH cases, 8 were positive for GER, but only 3 were positive for bile salts via assay. Of the 5 HREMpH-negative cases, 2 experienced aspiration. A solitary HREMpH study had 60.0% sensitivity and 37.5% specificity with positive and negative likelihood ratios: 0.96 and 1.07, respectively.

CONCLUSION

Microaspiration appears to be an intermittent phenomenon, and HREMpH screening poorly correlates with BALF evidence of aspiration; which may not be adequate. As aspiration detection is crucial in this population, further analysis is warranted.

Esophageal contractility increases and gastroesophageal reflux does not worsen after lung transplantation

Gastroesophageal reflux and esophageal dysmotility are common in patients with advanced lung disease and are associated with allograft dysfunction after lung transplantation. The effect of transplantation on reflux and esophageal motility is unclear. The aim of this study was to describe the changes in esophageal function occurring after lung transplantation. A retrospective cohort study was performed on lung transplant candidates evaluated at a tertiary care center between 2015 and 2016. A total of 76 patients who underwent lung transplantation had high-resolution manometry and ambulatory pH-metry before and after transplant. Demographic data, esophageal function testing results, and clinical outcomes such as pulmonary function testing were collected and analyzed using appropriate statistical tests and multivariable regression. Of the 76 patients, 59 (78%) received a bilateral transplant. There was a significant increase in esophageal contractility posttransplant, with an increase in median distal contractile integral from 1470 to 2549 mmHg cm s (P < 0.01). There were 19 patients with Jackhammer esophagus posttransplant, including 15 patients with normal motility pretransplant. Nine patients with ineffective or fragmented peristalsis pretransplant had normal manometry posttransplant. Abnormal pH-metry was observed in 35 (46%) patients pretransplant and 29 (38%) patients posttransplant (P = 0.33). Patients with gastroesophageal reflux disease posttransplant had less improvement in pulmonary function at one year, as measured by forced expiratory volume (P = 0.04). These results demonstrate that esophageal contractility increases significantly after lung transplantation, with an associated change in motility classification. In comparison, gastroesophageal reflux does not worsen, but is associated with worse pulmonary function, posttransplant.

Risk factors and outcomes of vocal cord paralysis after lung transplantation - a retrospective cohort study

Vocal cord paralysis (VCP) may complicate thoracic surgery and is associated with increased morbidity and mortality. Among lung transplant (LTx) recipients, chronic pulmonary aspiration can contribute to chronic allograft dysfunction (CLAD). We herein assessed the unknown incidence and clinical impact of VCP in a large LTx cohort. All first-time bilateral LTx recipients, transplanted between January 2010 and June 2015 were included in a single-centre retrospective analysis. Bronchoscopy reports were assessed for VCP. Patients exhibiting VCP were compared to propensity score-matched negative controls regarding CLAD onset and graft survival and secondary end-points, including inpatient duration and complications; lower respiratory tract infections (LRTI) within 24 months. In total, 583/713 (82%) patients were included in the analysis. A total of 52 (8.9%) exhibited VCP, which was transient in 34/52 patients (65%), recovering after median 6 months (IQR 2-12). Compared to 268 controls, 3-year graft survival and CLAD-free survival were non-inferior in VCP [HR 0.74 (95% CI 0.35-1.57), and HR 0.74 (95% CI 0.39-1.41)] respectively. Duration of hospitalization was similar and no differences in LRTI rates or airway complications were observed. Lower pre-Tx BMI increased risk for VCP [HR 0.88 (95% CI 0.79-0.99)]. Overall, VCP did not adversely affect graft and CLAD-free survival and secondary outcomes including LRTIs and hospitalizations.

Impact of vagus nerve integrity testing on surgical management in patients with previous operations with potential risk of vagal injury

BACKGROUND

Thoracic and foregut operations can cause vagal nerve injury resulting in delayed gastric emptying or gastroparesis. However, the cause of gastroparesis in these patients is not always from a vagal injury. We hypothesize that vagal nerve integrity (VNI) testing may better define who has vagal nerve dysfunction. This information may change subsequent operations. The aim of this study was to evaluate the impact of VNI testing in patients with prior thoracic or gastric surgery.

METHODS

From January 2014 to December 2017, patients who had previous operations with the potential risk of vagal injury and had VNI testing were reviewed. Excluded patients were those with no plan for a second operation or the second operation was only for gastroparesis. The main outcome was the percentage of operations altered due to the results of VNI testing.

RESULTS

Twelve patients (eight females) were included. Ages ranged from 37 to 77 years. VNI results were compatible with vagal injury in eight patients (67%). VNI test results altered subsequent operative plans in 41.7% (5/12). Pyloroplasty was done in addition to fundoplication in two patients. Plans for hiatal hernia repair with or without redo-fundoplication in three patients were changed by an additional pyloroplasty in one patient and partial gastrectomy with Roux-en-Y reconstruction in two patients. All patients who had secondary surgery had resolution of symptoms and improvement in objective testing.

CONCLUSION

The addition of VNI testing in patients with a previous potential risk of vagal nerve injury may help the surgeon select the appropriate secondary operation.

Abdominal Complications After Lung Transplantation in a Brazilian Single Center

Surgical and nonsurgical abdominal complications have been described after lung transplantation. However, there is limited data on this event in this population. The objective of this study was to analyze the incidence of abdominal complications in patients undergoing lung transplantation at the Heart Institute of the Faculty of Medicine, University of São Paulo (InCor-HCFMUSP) between the years 2003 and 2016. The main causes of abdominal complications were inflammatory acute abdomen (7 patients; 14%), obstructive acute abdomen (9 patients; 18%), gastroparesis (4 patients; 8%), distal intestinal obstruction syndrome (4 patients; 8%), perforated acute abdomen (7 patients; 14%), cytomegalovirus (CMV; 6 patients; 12%), and other reasons (12 patients; 26%). Separating these patients according to Clavien-Dindo classification, we had 21 patients (43%) with complications grade II, 4 patients (8%) with complications grade IIIa, 7 patients (14%) with grade IIIb complications, 7 patients (14%) with grade IV complications, and 10 patients (21%) with grade complications V. In conclusion, abdominal disorders are seriously increased after lung transplantation and correlate with a high mortality. Early abdominal surgical complication has worse prognosis.

Influence of early neurological complications on clinical outcome following lung transplant

Background

Neurological complications after lung transplantation are common. The full spectrum of neurological complications and their impact on clinical outcomes has not been extensively studied.

Methods

We investigated the neurological incidence of complications, categorized according to whether they affected the central, peripheral or autonomic nervous systems, in a series of 109 patients undergoing lung transplantation at our center between January 1 2013 and December 31 2014.

Results

Fifty-one patients (46.8%) presented at least one neurological complication. Critical illness polyneuropathy-myopathy (31 cases) and phrenic nerve injury (26 cases) were the two most prevalent complications. These two neuromuscular complications lengthened hospital stays by a median period of 35.5 and 32.5 days respectively. However, neurological complications did not affect patients’ survival.

Conclusions

The real incidence of neurological complications among lung transplant recipients is probably underestimated. They usually appear in the first two months after surgery. Despite not affecting mortality, they do affect the mean length of hospital stay, and especially the time spent in the Intensive Care Unit. We found no risk factor for neurological complications except for long operating times, ischemic time and need for transfusion. It is necessary to develop programs for the prevention and early recognition of these complications, and the prevention of their precipitant and risk factors.

Aspects of Anesthesia for Lung Transplantation

Anesthesia for lung transplantation is both a demand ing and rewarding experience. Success requires team- work, experience, knowledge of cardiorespiratory patho physiology and its anesthetic implications, appropriate use of noninvasive and invasive monitoring, and the ability to respond quickly and effectively to life- threatening perioperative events. Specific issues in clude management of a patient with end-stage lung and heart disease, lung isolation and one-lung ventilation, perioperative respiratory failure, pulmonary hyperten sion, and acute right ventricular failure. Recent ad vances include greater understanding of dynamic hyper inflation ("gas-trapping") during mechanical ventilation, perioperative use of inhaled nitric oxide and treatment of acute right ventricular failure. Successful anesthetic management leads to greater hemodynamic stability, improvement in gas exchange and a reduction in need for cardiopulmonary bypass, all of which should lead to improved patient outcome.

Endoscopic botox injections in therapy of refractory gastroparesis

Gastroparesis (GP) is a common disease seen in gastroenterology practice particularly in western countries, and it may be underdiagnosed. The available drug therapies for this condition are quite disappointing. Botulinum toxin type A (BT) has been found to be effective therapy in various spastic disorders of smooth muscle of gastrointestinal tract. However, the benefits of BT injections in GP have been unclear. Several retrospective and open label studies have shown clinical advantages of intrapyloric Botulinum toxin type A injections, while two small randomized trials did not show positive results. Therefore, the available published studies yielded conflicting results leading to fading out of botox therapy for GP. We recognize possible clinical benefit of BT injections without any disadvantages of this treatment. We are calling for revisiting the endoscopy guided botox therapy in refractory GP. In this review we discuss important features of these studies pointing out differences in results among them. Differences in patient selection, doses and method of administration of botox toxin in the prior studies may be the cause of conflicting results. The mechanism of action, indications, efficacy and side-effects of BT are reviewed. Finally, we recognize limited evidence to recommend BT in GP and calling attention for future research in this field since no advances in drug management had been made in the last two decades.

PAR1-activated astrocytes in the nucleus of the solitary tract stimulate adjacent neurons via NMDA receptors

Severe autonomic dysfunction, including the loss of control of the cardiovascular, respiratory, and gastrointestinal systems, is a common comorbidity of stroke and other bleeding head injuries. Previous studies suggest that this collapse of autonomic control may be caused by thrombin acting on astrocytic protease-activated receptors (PAR1) in the hindbrain. Using calcium imaging and electrophysiological techniques, we evaluated the mechanisms by which astrocytic PAR1s modulate the activity of presynaptic vagal afferent terminals and postsynaptic neurons in the rat nucleus of the solitary tract (NST). Our calcium-imaging data show that astrocytic and neuronal calcium levels increase after brain slices are treated with the PAR1 agonist SFLLRN-NH2. This increase in activity is blocked by pretreating the slices with the glial metabolic blocker fluorocitrate. In addition, PAR1-activated astrocytes communicate directly with NST neurons by releasing glutamate. Calcium responses to SFLLRN-NH2 in the astrocytes and neurons significantly increase after bath application of the excitatory amino acid transporter blocker DL-threo-β-benzyloxyaspartic acid (TBOA) and significantly decrease after bath application of the NMDA receptor antagonist DL-2-amino-5-phosphonopentanoic acid (DL-AP5). Furthermore, astrocytic glutamate activates neuronal GluN2B-containing NMDA receptors. Voltage-clamp recordings of miniature EPSCs (mEPSCs) from NST neurons show that astrocytes control presynaptic vagal afferent excitability directly under resting and activated conditions. Fluorocitrate significantly decreases mEPSC frequency and SFLLRN-NH2 significantly increases mEPSC frequency. These data show that astrocytes act within a tripartite synapse in the NST, controlling the excitability of both postsynaptic NST neurons and presynaptic vagal afferent terminals.

Ventilator-associated respiratory infection following lung transplantation

The medical records of 170 adult patients who underwent lung transplantation between January 2010 and December 2012 were reviewed to assess the incidence, causative organisms, risk factors and outcomes of post-operative pneumonia and tracheobronchitis. 20 (12%) patients suffered 24 episodes of ventilator-associated pneumonia. The condition was associated with mean increases of 43 days in mechanical ventilation and of 35 days in hospital stay, and significantly higher hospital mortality (OR 9.0, 95% CI 3.2-25.1). Pseudomonas aeruginosa (eight out of 12 patients were multidrug-resistant) was the most common pathogen, followed by Enterobacteriaceae (one out of five patients produced extended-spectrum β-lactamases). Gastroparesis occurred in 55 (32%) patients and was significantly associated with pneumonia (OR 6.2, 95% CI 2.2-17.2). Ventilator-associated tracheobronchitis was associated with a mean increase of 28 days in mechanical ventilation and 30.5 days in hospital stay, but was not associated with higher mortality (OR 1.2, 95% CI 0.4-3.2). Pseudomonas aeruginosa (six out of 16 patients were multidrug resistant) was the most common pathogen, followed by Enterobacteriaceae (three out of 14 patients produced extended-spectrum β-lactamase). Patients with gastroparesis also had more episodes of ventilator-associated tracheobronchitis (40% versus 12%, p<0.001). In conclusion, ventilator-associated pneumonia following lung transplantation increased mortality. Preventing gastroparesis probably decreases the risk of pneumonia and tracheobronchitis. Multidrug-resistant bacteria frequently cause post-lung-transplantation pneumonia and tracheobronchitis.

Domperidone for delayed gastric emptying in lung transplant recipients with and without gastroesophageal reflux

Evidence demonstrates a link between gastroesophageal reflux disease and chronic allograft dysfunction in lung transplant recipients. Delayed gastric emptying plays an important role in the occurrence of gastroesophageal reflux disease, with limited therapeutic options available for treatment. This retrospective observational study reports the use of domperidone in the management of delayed gastric emptying in lung transplant recipients. All patients who underwent lung transplant at our institution from 2007 to 2011 were reviewed and patients who were treated with domperidone were identified. Clinical symptoms and results of gastric emptying studies before and after initiation of domperidone were documented. QTc intervals were compared from before to after domperidone treatment at 3 months and at 1 year. Weight and dose-normalized calcineurin inhibitor troughs were evaluated before and 2 weeks after domperidone treatment was started. Of 82 patients, 24% (n = 20) had documented delayed gastric emptying and 35% (n = 29) had documented gastroesophageal reflux disease. Twelve of the 20 patients with delayed gastric emptying started treatment with domperidone. All patients responded symptomatically and 6 patients with gastric emptying studies before and after domperidone had documented improvement. No adverse effects were observed in any patients treated with domperidone. Results indicate that domperidone can be used safely and may improve symptoms related to delayed gastric emptying in lung transplant recipients.

Early laparotomy after lung transplantation: increased incidence for patients with α1-anti-trypsin deficiency

BACKGROUND

Gastrointestinal complications after lung transplantation have been reported with incidence rates ranging from 3% to 51%, but the reasons are poorly understood. We aimed to investigate the correlations between pulmonary diseases leading to lung transplantation and early gastrointestinal complications requiring laparotomy after transplantation with outcomes for patients at increased risk.

METHODS

In this study we performed a retrospective analysis of data of patients who underwent lung transplantation at our institution from 2004 to 2012. The study period was limited to the first 90 days after transplantation.

RESULTS

Lung transplantation was performed in 258 patients, including 51 patients with α1-anti-trypsin deficiency (A1AD). Seventy-eight patients (30%) had an X-ray of the abdomen, and 23 patients (9%) required laparotomy during the first 90 days after transplantation. Patients with A1AD comprised 20% of the total recipients, 23% (18 of 78) of the patients who had an abdominal X-ray performed (p = 0.40), and 48% (11 of 23) of the patients who required laparotomy (p < 0.001). More than 1 of every 5 patients (11 of 51) with A1AD required laparotomy at a median 8 days after transplantation, and the estimated odds ratio for laparotomy for A1AD patients was 5.74 (CI 2.15 to 15.35). In the group of patients with A1AD who required laparotomy, the estimated hazard ratio for death was 1.62 (CI 0.57 to 4.62), the stay in the intensive care unit was prolonged, but no significant difference was observed for time on mechanical ventilation. Among pulmonary diseases and demographics of the patients, no other risk factors were identified for laparotomy.

CONCLUSIONS

A1AD was the only significant risk factor identified for gastrointestinal complications that required laparotomy within 3 months after lung transplantation. There was a trend toward a higher risk of death after laparotomy in patients with A1AD, and the length of stay in the intensive care unit was significantly prolonged, whereas the time on mechanical ventilation was unaffected.

Gastroparesis after living-donor lobar lung transplantation: report of five cases

Gastroparesis is a challenging gastrointestinal complication of deceased-donor lung transplantation and heart-lung transplantation, but it has not been reported after living-donor lobar lung transplantation (LDLLT). To better understand this complication after LDLLT, we reviewed our institutional experiences. Among the 32 patients who survived for at least 3 months after LDLLT, five (16 %) developed symptomatic gastroparesis. All five patients had undergone bilateral LDLLT, and gastroparesis was diagnosed within 2 months after transplantation. Neither adult patients who received single lobar LDLLT nor pediatric patients who received either bilateral or single lobar LDLLT developed gastroparesis. Although gastroparesis-related symptoms improved after medical treatment in three patients, two patients died of complications related to gastroparesis. We conclude that gastroparesis can occur after LDLLT and may cause grave complications unless carefully managed.

Pathophysiology of cystic fibrosis and drugs used in associated digestive tract diseases

Cystic fibrosis (CF) causes chronic infections in the respiratory tract and alters the digestive tract. This paper reviews the most important aspects of drug treatment and changes in the digestive tract of patients with CF. This is a review of the literature, emphasizing the discoveries made within the last 15 years by analyzing scientific papers published in journals indexed in the Scientific Electronic Library Online, Sciences Information, United States National Library of Medicine and Medical Literature Analysis and Retrieval System Online databases, both in English and Portuguese, using the key words: cystic fibrosis, medication, therapeutic, absorption, digestion. Randomized, observational, experimental, and epidemiological clinical studies were selected, among others, with statistical significance of 5%. This review evaluates the changes found in the digestive tract of CF patients including pancreatic insufficiency, constipation and liver diseases. Changes in nutritional status are also described. Clinical treatment, nutritional supplementation and drug management were classified in this review as essential to the quality of life of CF patients, and became available through public policies for monitoring and treating CF. The information gathered on CF and a multi professional approach to the disease is essential in the treatment of these patients.

Astrocytes in the hindbrain detect glucoprivation and regulate gastric motility

Glucoprivation is a strong signal for the initiation of gastrointestinal contractions. While this relationship between utilizable nutrient levels and gastric motility has been recognized for more than 100 years, the explanation of this phenomenon has remained incomplete. Using widely differing approaches, recent work has suggested that the hindbrain is responsible for this chemoreflex effect. Surprisingly, astrocytes may be the main glucodetector elements under hypoglycemic conditions. Our own work using in vitro live cell calcium imaging shows that astrocytes in the NST increase cytoplasmic calcium in a concentration dependent manner in reaction to reductions in glucose. This effect is reversed on restoration of normal glucose concentrations. In vivo single unit neurophysiological recordings show that brainstem neurons driving gastric motility are activated by glucoprivic stimuli. Studies in intact animals verify that both dorsal medullary and systemic glucoprivation significantly increases gastric motility. Astrocyte inactivation with fluorocitrate blocks the pro-motility effects of glucoprivation. Thus, it appears that intact astrocyte signaling may be essential to glucoregulatory control over gastric motility.

Lung transplantation for interstitial lung disease

For selected parenchymal lung disease patients who fail to respond to medical therapy and demonstrate declines in function that place them at increased risk for mortality, lung transplantation should be considered. Lung transplantation remains a complex medical intervention that requires a dedicated recipient and medical team. Despite the challenges, lung transplantation affords appropriate patients a reasonable chance at increased survival and improved quality of life. Lung transplantation remains an appropriate therapeutic option for selected patients with parenchymal lung disease.

Pepsin and bile acid concentrations in sputum of mustard gas exposed patients

BACKGROUND/AIM

Gastro-esophageal reflux has been suggested to be associated with several pulmonary complications such as asthma, and post-transplant bronchiolitis obliterans (BO). Pepsin or bile salts in the sputum is shown to be an optimal molecular marker of gastric contents macro/micro aspiration. In this study, we investigated sputum pepsin as a marker of micro-aspiration in sulfur mustard (SM) exposed cases compared to healthy controls.

MATERIALS AND METHODS

In a case controlled study, 26 cases with BO and 12 matched healthy controls were recruited and all cases were symptomatic and their exposure to SM was previously documented during Iran-Iraq conflict. Pepsin levels in sputum and total bile acids were measured using enzymatic assay. The severity of respiratory disorder was categorized based upon the spirometric values.

RESULT

The average concentration of pepsin in sputum was higher in the case group (0.29 ± 0.23) compared with healthy subjects (0.13 ± 0.07; P ± 0.003). Moreover, the average concentration of bile acids in the sputum cases was not significantly different in comparison to the controls ( P = 0.5).

CONCLUSION

Higher pepsin concentrations in sputum of SM exposed patients compared with healthy control subjects indicate the occurrence of significantly more gastric micro-aspiration in SM exposed patients.

Sublingual Tacrolimus for Immunosuppression in Lung Transplantation

Lung transplantation has emerged as an option to prolong and increase the quality of life in patients with end-stage pulmonary lung disease. In lung transplant recipients, because of the high potential for acute and chronic allograft rejection, optimal selection, dosage and delivery of immunosuppressive medications is critical. Cystic fibrosis (CF), a multi-organ system disease that often includes pulmonary and gastrointestinal manifestations, represents the leading indication for bilateral lung transplantation. The gastrointestinal manifestations of CF, however, confound post-transplant management by causing significant variation in the rate and extent of absorption of orally administered immunosuppressive medications. Tacrolimus, a new calcineurin inhibitor, is increasingly employed as the primary immunosuppressive agent in lung transplant recipients. Unfortunately, tacrolimus itself exhibits variable bioavailability, particularly in CF transplant recipients. A novel approach to the absorption dilemma is administration of tacrolimus via the sublingual (SL) route. Little published information exists concerning the use of SL immunosuppression in transplant recipients. However, emerging evidence suggests that SL tacrolimus provides is an effective means of drug delivery particularly for CF lung transplant recipients. Preliminary results from a pilot study, demonstrate that SL delivery of tacrolimus achieves therapeutic serum levels, in lung transplant recipients with CF, over the first few postoperative months. In addition, the early postoperative use of SL tacrolimus has been associated with acceptable rates of transplant rejection and normal renal function in a cohort of 22 lung transplant recipients that included CF and non-CF transplant recipients. Potential pharmacokinetic advantages of the SL route of delivery include good permeability, rapid absorption, acceptable bioavailability and easy accessibility. From an economic standpoint, considerable cost savings could be achieved by using the SL rather than the intravenous route of drug delivery for tacrolimus. Comparative, prospective randomized trials are necessary to evaluate the long-term safety and efficacy of SL tacrolimus in lung transplant patients. Until such data are available, the use of SL tacrolimus should be considered in situations where alternative routes of delivery are unavailable or as part of ongoing research studies. Ultimately, SL tacrolimus may prove efficacious for short-term use in the early postoperative lung transplant recipients, particularly in patients with malabsorption problems such as CF transplant recipients.

Use of sublingual tacrolimus in lung transplant recipients

BACKGROUND

In lung transplant recipients (LTRs), tacrolimus is often utilized as a core component of immunosuppressive regimens. Although tacrolimus can be delivered orally or intravenously, oral tacrolimus is associated with fewer adverse effects. Various reports have suggested that sublingual tacrolimus may be used as an alternative to oral tacrolimus; however, information regarding converting between routes is limited. We aimed to identify a dose conversion ratio between oral and sublingual tacrolimus in LTRs.

METHODS

We identified adult LTRs at the University of California, San Francisco, who transitioned between oral and sublingual tacrolimus between 2005 and 2010 (n = 34). For tacrolimus, we obtained steady-state blood concentrations and total daily doses before and after the route conversion. Blood concentrations divided by daily doses were calculated for each route. The conversion ratio was then defined as: (blood concentration(sublingual)/daily dose(sublingual))/(blood concentration(oral)/daily dose(oral)). This ratio was tested in inpatient vs outpatient settings and in the presence of impaired gastric emptying. Adverse effects, including nephrotoxicity, hepatotoxicity and anaphylaxis, were evaluated.

RESULTS

The conversion ratio of sublingual to oral tacrolimus was 0.46 ± 0.20 (mean ± SD). The ratio was not associated with hospital setting (p = 0.82) or with impaired gastric emptying (p = 0.31). When comparing sublingual to oral tacrolimus administration, there were no differences in serum creatinine, liver function tests or anaphylaxis.

CONCLUSIONS

Tacrolimus administered sublingually at approximately half of the oral dose achieves therapeutic blood concentrations and is safe in LTRs. Delivery via the sublingual route using this conversion ratio may aid clinicians in maintaining therapeutic tacrolimus blood concentrations while avoiding the need for intravenous administration.

Histological examination of the relationship between respiratory disorders and repetitive microaspiration using a rat gastro-duodenal contents reflux model

Microaspiration due to gastroesophageal reflux (GER) has been suggested as a factor contributing to the development and exacerbation of several respiratory disorders. To explore the relationship between GER and respiratory disorders, we histologically examined the bilateral lungs of a rat gastroduodenal contents reflux model, which was previously used to investigate the histogenesis of Barrett's esophagus and esophageal carcinoma. GER was surgically induced in male Wistar rats. The bilateral lungs of the reflux rats were examined with hematoxylin and eosin (HE), PAS-Alcian blue, and Azan staining at 10 and 20 weeks after surgery. Immunohistochemical staining of CD68 and α-SMA was also performed. Aspiration pneumonia with severe peribronchiolar neutrophilic and lymphocytic infiltrates, goblet cell hyperplasia, prominence of blood vessels, and increased thickness of the smooth muscle layer were detected. Bronchiolitis obliterans (BO)-like lesions comprising granulation tissue with macrophages, spindle cells, and multinucleated giant cells in the lumen of respiratory bronchioles were observed in the bilateral lungs of the reflux animals. These findings suggest that the severe inflammation and the BO-like lesions may play a role in exacerbation of the forced expiratory volume in 1 second (FEV 1) in human cases. In conclusion, we speculate that repetitive microaspiration due to GER may contribute to the exacerbation of various respiratory diseases, particularly asthma and chronic obstructive pulmonary disease (COPD), and the development of BO syndrome following lung transplantation. The reflux model is a good tool for examining the causal relationships between GER and respiratory disorders.

Laparoscopic antireflux surgery for gastroesophageal reflux disease after lung transplantation

BACKGROUND

Although gastroesophageal reflux disease (GERD) is highly prevalent in lung transplantation, the pathophysiology of GERD in these patients is unknown. We hypothesize that the pathophysiology of GERD after lung transplantation differs from that of a control population, and that the 30-d morbidity and mortality of laparoscopic antireflux surgery (LARS) are equivalent in both populations.

METHODS

We retrospectively compared the pathophysiology of GERD and the 30-d morbidity and mortality of 29 consecutive lung transplant patients with 23 consecutive patients without lung transplantation (control group), all of whom had LARS for GERD between November 2008 and May 2010.

RESULTS

Both groups had a similar prevalence of endoscopic esophagitis and Barrett's esophagus , comparable manometric profiles, and similar prevalence of abnormal peristalsis. However, hiatal hernia was more common in controls than in lung transplant patients (57% versus 24%; P = 0.04). Lung transplant patients had a higher prevalence and severity of proximal GERD (65% versus 33%; P = 0.04). The 30-d morbidity and mortality following LARS were similar in both groups regardless of the higher surgical risk of lung transplants (median ASA class: 3 versus 2 for controls, P < 0.001).

CONCLUSIONS

These results show that despite similar manometric profiles, lung transplant patients are more prone to proximal reflux than the general population with GERD; the prevalence of endoscopic esophagitis and Barrett's esophagus is the same in both groups of patients; a hiatal hernia is uncommon after lung transplantation; and the morbidity and mortality of LARS are the same for lung transplant patients as the general population with GERD.

Relevance of GERD in lung transplant patients

Lung transplantation has become a valuable treatment for end-stage pulmonary disorders in an attempt to improve quality of life and extend survival. Development of chronic rejection, also known as bronchiolitis obliterans syndrome (BOS), is responsible for the vast majority of deaths after lung transplantation. Up to 50% of lung transplant patients develop BOS within the first 5 years after transplantation. A high prevalence of gastroesophageal reflux and aspiration of gastric components has been described after lung transplantation. Reflux and aspiration have been implicated in the development of BOS and antireflux surgery has been proposed; however, the causal relationship with BOS and the impact of reflux in lung transplantation survival needs to be further elucidated.

Laparoscopic fundoplication with or without pyloroplasty in patients with gastroesophageal reflux disease after lung transplantation: how I do it

INTRODUCTION

Several studies have confirmed that gastroesophageal reflux disease (GERD) in lung transplant patients is a risk factor for the development and progression of bronchiolitis obliterans syndrome (BOS), a form of rejection after lung transplantation. Moreover, numerous reports indicate that surgical correction of GERD may control the decline in lung function characteristic of BOS. Although laparoscopic fundoplication is an accepted treatment option for these patients with GERD, the surgical technique, which often includes a laparoscopic pyloroplasty, has not been standardized.

METHODS

The purpose of this article is to describe a step-by-step approach to the laparoscopic treatment of GERD in lung transplant patients. We also address specific technical concerns encountered in the surgical management of this high-risk patient population; we provide data on the safety of this operation; and we illustrate the evidence-based rationale for each technical step of the procedure.

Gastroesophageal reflux disease after lung transplantation: pathophysiology and implications for treatment

BACKGROUND

Gastroesophageal reflux disease (GERD) is thought to be a risk factor for the development or progression of chronic rejection after lung transplantation. However, the prevalence of GERD and its risk factors, including esophageal dysmotility, hiatal hernia and delayed gastric emptying after lung transplantation, are still unknown. In addition, the prevalence of Barrett's esophagus, a known complication of GERD, has not been determined in these patients. The purpose of this study was to determine the prevalence and extent of GERD, as well as the frequency of these risk factors and complications of GERD in lung transplant patients.

METHODS

Thirty-five consecutive patients underwent a combination of esophageal function testing, upper endoscopy, barium swallow, and gastric emptying scan after lung transplantation.

RESULTS

In this patient population, the prevalence of GERD was 51% and 22% in those who had been retransplanted. Of patients with GERD,36% had ineffective esophageal motility (IEM), compared with 6% of patients without GERD (P = .037). No patient demonstrated hiatal hernia on barium swallow. The prevalence of delayed gastric emptying was 36%. The prevalence of biopsy-confirmed Barrett's esophagus was 12%.

CONCLUSION

Our study shows that, after lung transplantation, more than half of patients had GERD, and that GERD was more common after retransplantation. IEM and delayed gastric emptying are frequent in patients with GERD. Hiatal hernia is rare. The prevalence of Barrett's esophagus is not negligible. We conclude that GERD is highly prevalent after lung transplantation, and that delayed gastric emptying and Barrett's esophagus should always be suspected after lung transplantation because they are common risks factors and complications of GERD.

Gastroesophageal reflux and altered motility in lung transplant rejection

BACKGROUND

Lung transplantation has become an effective therapeutic option for selected patients with end stage lung disease. Long-term survival is limited by chronic rejection manifest as bronchiolitis obliterans syndrome (BOS). The aspiration of gastric contents has been implicated as a causative or additive factor leading to BOS. Gastroesophageal reflux (GER) and altered foregut motility are common both before and after lung transplantation. Further, the normal defense mechanisms against reflux are impaired in the allograft. Recent studies using biomarkers of aspiration have added to previous association studies to provide a growing body of evidence supporting the link between rejection and GER. Further, the addition of high-resolution manometry (HRM) and impedance technology to characterize bolus transit and the presence and extent of reflux regardless of pH might better identify at-risk patients. Although additional prospective studies are needed, fundoplication appears useful in the prevention or treatment of post-transplant BOS.

PURPOSE

This review will highlight the existing literature on the relationship of gastroesophageal reflux and altered motility to lung transplant rejection, particularly BOS. The article will conclude with a discussion of the evaluation and management of patients undergoing lung transplantation at our center.

Reflux-induced collagen type v sensitization: potential mediator of bronchiolitis obliterans syndrome

BACKGROUND

Lung transplantation continues to have poor long-term survival partly because of the high incidence of bronchiolitis obliterans syndrome (BOS). Gastroesophageal reflux disease (GERD) has been implicated in BOS pathogenesis. We investigated the role of collagen type V [col(V)] sensitization in this process.

METHODS

Only primary lung transplant recipients were included. Reflux status was assessed with pH monitoring, impedance plethysmography, and esophagogastroduodenoscopy. Sensitivity to col(V) was determined with trans vivo delayed-type hypersensitivity reaction (DTH). Kaplan-Meier analyses were performed.

RESULTS

Of the 54 recipients, 26 had proven GERD. There were no significant between-group differences in diagnosis; donor and recipient age; sex; ischemic time; single vs bilateral; human leukocyte antigen A, B, and DR matching cytomegalovirus status; acute rejections; or mean follow-up period. The mean DTH response in the GERD group was 25.7 x 10(-4) inches vs 18.3 x 10(-4) inches in the non-GERD group (P = .023). There was a significant reduction in BOS-free survival in the GERD group for both BOS-I (GERD+, 28.3%; GERD-, 86.6%; P = .0001) and BOS-II/III (GERD+, 66.2%; GERD-, 91.7%; P = .0374). A second cohort of 53 patients awaiting lung transplantation also was assayed. The mean DTH response in the GERD group was 24.0 x 10(-4) inches vs 13.1 x 10(-4) inches in the non-GERD group (P = .003). There were no differences in age or sex.

CONCLUSIONS

GERD is strongly associated with the development of BOS after primary lung transplantation. Col(V) sensitization is associated with reflux and BOS and may play an intermediary role in the pathogenesis of BOS. Trials using col(V) reactivity to assess the impact of antireflux procedures in patients with lung transplantation and idiopathic pulmonary fibrosis are warranted.