The right tool for the right question: contrasting biogeographic patterns in the notothenioid fish Harpagifer spp. along the Magellan Province.

Molecular-based analysis has become a fundamental tool to understand the role of Quaternary glacial episodes. In the Magellan Province in southern South America, ice covering during the last glacial maximum (20 ka) radically altered the landscape/seascape, speciation rates and distribution of species. For the notothenioid fishes of the genus Harpagifer, in the area are described two nominal species. Nevertheless, this genus recently colonized South America from Antarctica, providing a short time for speciation processes. Combining DNA sequences and genotyping-by-sequencing SNPs, we evaluated the role of Quaternary glaciations over the patterns of genetic structure in Harpagifer across its distribution in the Magellan Province. DNA sequences showed low phylogeographic structure, with shared and dominant haplotypes between nominal species, suggesting a single evolutionary unit. SNPs identified contrastingly two groups in Patagonia and a third well-differentiated group in the Falkland/Malvinas Islands with limited and asymmetric gene flow. Linking the information of different markers allowed us to infer the relevance of postglacial colonization mediated by the general oceanographic circulation patterns. Contrasting rough- and fine-scale genetic patterns highlights the relevance of combined methodologies for species delimitation, which, depending on the question to be addressed, allows discrimination among phylogeographic structure, discarding incipient speciation, and contemporary spatial differentiation processes.

Contrasting biogeographical patterns in Margarella (Gastropoda: Calliostomatidae: Margarellinae) across the Antarctic Polar Front.

Members of the trochoidean genus Margarella (Calliostomatidae) are broadly distributed across Antarctic and sub-Antarctic ecosystems. Here we used novel mitochondrial and nuclear gene sequences to clarify species boundaries and phylogenetic relationships among seven nominal species distributed on either side of the Antarctic Polar Front (APF). Molecular reconstructions and species-delimitation analyses recognized only four species: M. antarctica (the Antarctic Peninsula), M. achilles (endemic to South Georgia), M. steineni (South Georgia and Crozet Island) and the morphologically variable M. violacea (=M. expansa, M. porcellana and M. pruinosa), with populations in southern South America, the Falkland/Malvinas, Crozet and Kerguelen Islands. Margarella violacea and M. achilles are sister species, closely related to M. steineni, with M. antarctica sister to all these. This taxonomy reflects contrasting biogeographic patterns on either side of the APF in the Southern Ocean. Populations of Margarella north of the APF (M. violacea) showed significant genetic variation but with many shared haplotypes between geographically distant populations. By contrast, populations south of the APF (M. antarctica, M. steineni and M. achilles) exhibited fewer haplotypes and comprised three distinct species, each occurring across a separate geographical range. We hypothesize that the biogeographical differences may be the consequence of the presence north of the APF of buoyant kelps - potential long-distance dispersal vectors for these vetigastropods with benthic-protected development - and their near-absence to the south. Finally, we suggest that the low levels of genetic diversity within higher-latitude Margarella reflect the impact of Quaternary glacial cycles that exterminated local populations during their maxima.

Phenotypic convergence is more frequent and stronger in herbivorous freshwater fishes.

Constraints on phenotypic evolution can lead to patterns of convergent evolution, by limiting the 'pool' of potential phenotypes in the face of endogenous (functional, developmental) or exogenous (competition, predation) selective pressures. Evaluation of convergence depends on integrating ecological and morphological data within a robust, comparative phylogenetic context. The staggering diversity of teleost fishes offers a multitude of lineages adapted for similar ecological roles, and therefore, offers numerous replicated evolutionary experiments for exploring phenotypic convergence. However, our understanding of fish feeding systems has been primarily shaped by marine species, with the monolithic exception of freshwater cichlids. Here we use piranhas and pacus (Serrasalmidae) to explore the evolution of different feeding ecologies and their morphological proxies in Neotropical freshwater environments. Specifically, we explore whether convergence is more widespread among plant-eating fishes, arising from strong constraints on phenotypic evolution in herbivores. Using osteological micro-computed tomographic imaging (µCT), we describe the major axes of morphological variation in pacus and piranhas, regarding their diet and feeding behaviors. Next, we evaluated whether herbivorous niches are less labile than other dietary guilds and whether herbivorous species' phenotypes evolve at a slower evolutionary rate than other taxa. We then assess how convergent herbivorous taxa are, using three different suites of morphological characters (dental, jaw, and abdominal morphometrics). Ecologically, herbivory is not a dead end, exhibiting similar observed transition rates as those between carnivores and omnivores. However, we documented widespread convergence in herbivores and that herbivores have slower rates of phenotypic evolution than carnivores. Most instances of convergence are found in herbivorous taxa, specifically in frugivores and folivores. Moreover, instances of 'complete' convergence, indicated by positive convergence metrics observed in more than one morphometric dataset, were only found in herbivores. Herbivores do appear to evolve under constrained circumstances, but this has not limited their ecological lability.

LRIG1 is a triple threat: ERBB negative regulator, intestinal stem cell marker and tumour suppressor.

In baseball parlance, a triple threat is a person who can run, hit and throw with aplomb. Leucine-rich repeats and immunoglobulin-like domains 1 (LRIG1) is a cell surface protein that antagonises ERBB receptor signalling by downregulating receptor levels. Over 10 years ago, Hedman et al postulated that LRIG1 might be a tumour suppressor. Recently, Powell et al provided in vivo evidence substantiating that claim by demonstrating that Lrig1 loss in mice leads to spontaneously arising, highly penetrant intestinal adenomas. Interestingly, Lrig1 also marks stem cells in the gut, suggesting a potential role for Lrig1 in maintaining intestinal epithelial homeostasis. In this review, we will discuss the ability of LRIG1 to act as a triple threat: pan-ERBB negative regulator, intestinal stem cell marker and tumour suppressor. We will summarise studies of LRIG1 expression in human cancers and discuss possible related roles for LRIG2 and LRIG3.

Extinction and recolonization of maritime Antarctica in the limpet Nacella concinna (Strebel, 1908) during the last glacial cycle: toward a model of Quaternary biogeography in shallow Antarctic invertebrates.

Quaternary glaciations in Antarctica drastically modified geographical ranges and population sizes of marine benthic invertebrates and thus affected the amount and distribution of intraspecific genetic variation. Here, we present new genetic information in the Antarctic limpet Nacella concinna, a dominant Antarctic benthic species along shallow ice-free rocky ecosystems. We examined the patterns of genetic diversity and structure in this broadcast spawner along maritime Antarctica and from the peri-Antarctic island of South Georgia. Genetic analyses showed that N. concinna represents a single panmictic unit in maritime Antarctic. Low levels of genetic diversity characterized this population; its median-joining haplotype network revealed a typical star-like topology with a short genealogy and a dominant haplotype broadly distributed. As previously reported with nuclear markers, we detected significant genetic differentiation between South Georgia Island and maritime Antarctica populations. Higher levels of genetic diversity, a more expanded genealogy and the presence of more private haplotypes support the hypothesis of glacial persistence in this peri-Antarctic island. Bayesian Skyline plot and mismatch distribution analyses recognized an older demographic history in South Georgia. Approximate Bayesian computations did not support the persistence of N. concinna along maritime Antarctica during the last glacial period, but indicated the resilience of the species in peri-Antarctic refugia (South Georgia Island). We proposed a model of Quaternary Biogeography for Antarctic marine benthic invertebrates with shallow and narrow bathymetric ranges including (i) extinction of maritime Antarctic populations during glacial periods; (ii) persistence of populations in peri-Antarctic refugia; and (iii) recolonization of maritime Antarctica following the deglaciation process.

Phylogenetic and phylogeographic analysis of the genus Orestias (Teleostei: Cyprinodontidae) in the southern Chilean Altiplano: the relevance of ancient and recent divergence processes in speciation.

This study presents phylogenetic molecular data of the Chilean species of Orestias to propose an allopatric divergence hypothesis and phylogeographic evidence that suggests the relevance of abiotic factors in promoting population divergence in this complex. The results reveal that diversification is still ongoing, e.g. in the Ascotán salt pan, where populations of Orestias ascotanensis restricted to individual freshwater springs exhibit strong genetic differentiation, reflecting putative independent evolutionary units. Diversification of Orestias in the southern Altiplano may be linked to historical vicariant events and contemporary variation in water level; these processes may have affected the populations from the Plio-Pleistocene until the present.

Comparison of four-year toxicities and local control of ultra-hypofractionated vs moderate-hypofractionated image guided prostate radiation with HDR brachytherapy boost: A phase I-II single institution trial.

Purpose/Objectives: To analyze the long term efficacy and safety of an ultra-hypofractionated (UHF) radiation therapy prostate treatment regimen with HDR brachytherapy boost (BB) and compare it to moderate-hypofractionated regimens (MHF). Materials/Methods: In this single arm, prospective monocentric study, 28 patients with intermediate risk prostate cancer were recruited in an experimental treatment arm of 25 Gy in 5 fractions plus a 15 Gy HDR BB. They were then compared to two historical control groups, treated with either 36 Gy in 12 fractions or 37.5 Gy in 15 fractions with a similar HDR BB. The control groups included 151 and 311 patients respectively. Patient outcomes were reported using the International Prostate Symptom Score (IPSS) and Expanded Prostate Index Composite (EPIC-26) questionnaires at baseline and at each follow-up visit. Results: Median follow-up for the experimental arm was 48.5 months compared to 47 months and 60 months compared to the 36/12 and 37,5/15 groups respectively. The IPSS and EPIC scores did not demonstrate any significant differences in the gastrointestinal or genitourinary domains between the three groups over time. No biochemical recurrence occurred in the UHF arm as defined by the Phoenix criterion. Conclusion: The UHF treatment scheme with HDR BB seems equivalent to standard treatment arms in terms of toxicities and local control. Randomized control trials with larger cohorts are ongoing and needed to further confirm our findings.

Positive selection over the mitochondrial genome and its role in the diversification of gentoo penguins in response to adaptation in isolation.

Although mitochondrial DNA has been widely used in phylogeography, evidence has emerged that factors such as climate, food availability, and environmental pressures that produce high levels of stress can exert a strong influence on mitochondrial genomes, to the point of promoting the persistence of certain genotypes in order to compensate for the metabolic requirements of the local environment. As recently discovered, the gentoo penguins (Pygoscelis papua) comprise four highly divergent lineages across their distribution spanning the Antarctic and sub-Antarctic regions. Gentoo penguins therefore represent a suitable animal model to study adaptive processes across divergent environments. Based on 62 mitogenomes that we obtained from nine locations spanning all four gentoo penguin lineages, we demonstrated lineage-specific nucleotide substitutions for various genes, but only lineage-specific amino acid replacements for the ND1 and ND5 protein-coding genes. Purifying selection (dN/dS < 1) is the main driving force in the protein-coding genes that shape the diversity of mitogenomes in gentoo penguins. Positive selection (dN/dS > 1) was mostly present in codons of the Complex I (NADH genes), supported by two different codon-based methods at the ND1 and ND4 in the most divergent lineages, the eastern gentoo penguin from Crozet and Marion Islands and the southern gentoo penguin from Antarctica respectively. Additionally, ND5 and ATP6 were under selection in the branches of the phylogeny involving all gentoo penguins except the eastern lineage. Our study suggests that local adaptation of gentoo penguins has emerged as a response to environmental variability promoting the fixation of mitochondrial haplotypes in a non-random manner. Mitogenome adaptation is thus likely to have been associated with gentoo penguin diversification across the Southern Ocean and to have promoted their survival in extreme environments such as Antarctica. Such selective processes on the mitochondrial genome may also be responsible for the discordance detected between nuclear- and mitochondrial-based phylogenies of gentoo penguin lineages.

Concerted genetic, morphological and ecological diversification in Nacella limpets in the Magellanic Province.

Common inhabitants of Antarctic and Subantarctic rocky shores, the limpet genus Nacella, includes 15 nominal species distributed in different provinces of the Southern Ocean. The Magellanic Province represents the area with the highest diversity of the genus. Phylogenetic reconstructions showed an absence of reciprocal monophyly and high levels of genetic identity among nominal species in this Province and therefore imply a recent diversification in southern South America. Because most of these taxa coexist along their distribution range with clear differences in their habitat preferences, Nacella is a suitable model to explore diversification mechanisms in an area highly affected by recurrent Pleistocene continental ice cap advances and retreats. Here, we present genetic and morphological comparisons among sympatric Magellanic nominal species of Nacella. We amplified a fragment of the COI gene for 208 individuals belonging to seven sympatric nominal species and performed geometric morphometric analyses of their shells. We detected a complete congruence between genetic and morphological results, leading us to suggest four groups of Nacella among seven analysed nominal species. Congruently, each of these groups was related to different habitat preferences such as bathymetric range and substrate type. A plausible explanation for these results includes an ecologically based allopatric speciation process in Nacella. Major climatic changes during the Plio-Pleistocene glacial cycles may have enhanced differentiation processes. Finally, our results indicate that the systematics of the group requires a deep revision to re-evaluate the taxonomy of Nacella and to further understand the Pleistocene legacy of the glacial cycles in the southern tip of South America.

Quaternary ice sheets and sea level regression drove divergence in a marine gastropod along Eastern and Western coasts of South America.

The southern coastline of South America is a remarkable area to evaluate how Quaternary glacial processes impacted the demography of the near-shore marine biota. Here we present new phylogeographic analyses in the pulmonate Siphonaria lessonii across its distribution, from northern Chile in the Pacific to Uruguay in the Atlantic. Contrary to our expectations, populations from the southwestern Atlantic, an area that was less impacted by ice during glacial maxima, showed low genetic diversity and evidence of recent expansion, similar to the patterns recorded in this study across heavily ice-impacted areas in the Pacific Magellan margin. We propose that Atlantic and Pacific shallow marine hard-substrate benthic species were both affected during the Quaternary in South America, but by different processes. At higher latitudes of the southeast Pacific, ice-scouring drastically affected S. lessonii populations compared to non-glaciated areas along the Chile-Peru province where the species was resilient. In the southwest Atlantic, S. lessonii populations would have been dramatically impacted by the reduction of near-shore rocky habitat availability as a consequence of glacio-eustatic movements. The increase of gravelly and rocky shore substrates in the southwest Atlantic supports a hypothesis of glacial refugia from where the species recolonized lower latitudes across the Atlantic and Pacific margins. Our results suggest that current patterns of genetic diversity and structure in near-shore marine benthic species do not solely depend on the impact of Quaternary glacial ice expansions but also on the availability of suitable habitats and life-history traits, including developmental mode, bathymetry and the likelihood of dispersal by rafting.

Laparoscopy influences hiring practices within academic surgical departments.

BACKGROUND: This study aimed to determine whether the increasing emphasis on minimally invasive surgery (MIS) influences hiring practices within academic surgical departments. METHODS: A questionnaire was mailed to chairs of surgery departments and divisions of general surgery at the 16 Canadian academic institutions. Nonresponders were identified and contacted directly. The survey consisted of 34 questions, including Likert scales, single answers, and multiple-choice questions. Data were collected on demographics, perceptions of MIS, and recruitment/hiring. At the time of the survey, two department chair positions were vacant. RESULTS: A response rate of 87% (26/30) was obtained, with representation from 94% of departments (15/16). Of those surveyed, 88% intend to increase the importance of MIS at their institution within 5 years, and 87% intend to achieve this objective through new hirings. Networking (73%) and retention of recent graduates (89%) were cited most frequently as recruitment strategies. Strengthening the division, research, and education were considered important or extremely important by more than 90% of the respondents with respect to recruitment goals, whereas strengthening MIS was considered important or extremely important by 50%. Within 5 years, surgical departments intend to hire a median of four general surgeons, 50% of whom will have formal MIS training. In comparison, over the past 10 years, only 25% of new recruits had formal MIS training. More than 90% of the respondents considered formal MIS fellowship, MIS fellowship plus a second fellowship, and proctorship to be adequate training for performing advanced MIS, whereas traditional methods were considered inadequate. Lack of operative time and resource issues were considered most limiting in the hiring of new MIS surgeons. CONCLUSION: Minimally invasive surgery is growing in importance within academic surgical departments, but it remains an intermediate recruitment priority. Formal MIS training appears to be important in the recruiting of new surgeons, whereas traditional training methods are considered inadequate.

Assessing cross-species transmission of hemoplasmas at the wild-domestic felid interface in Chile using genetic and landscape variables analysis.

The co-occurrence of domestic cats (Felis silvestris catus) and wild felids in rural landscapes can facilitate pathogen transmission. However, in the relatively-isolated regions of southern South America there have been no comprehensive studies to assess disease transmission risks between domestic cats and forest-dwelling wild felids such as guigna (Leopardus guigna). We evaluated hemoplasma infection and the possibility of transmission between domestic cats and guignas by comparing spatial and phylogenetic patterns of pathogen prevalence. Blood/spleen samples were collected from 102 wild guignas and 262 co-occurring rural domestic cats across the entire distribution range of guigna in Chile. Hemoplasma infection was assessed by direct sequencing of the 16S RNA gene. Infection with hemoplasmas was common and geographically widespread across different bioclimatic areas for both species. The most common feline Mycoplasma species in guigna and domestic cats were Candidatus M. haemominutum (CMhm) (15.7% guigna; 10.3% domestic cat) and Mycoplasma haemofelis (Mhf) (9.8% guigna, 6.1% domestic cat). A previously undescribed Mycoplasma sp. sequence was found in two guignas and one cat. Continuous forest-landscapes were associated with higher hemoplasma-prevalence in guignas. Shared hemoplasma nucleotide sequence types between guigna and domestic cats were rare, suggesting that cross-species transmission between guignas and domestic cats may occur, but is probably uncommon. Ectoparasites, which have been linked with hemoplasma transmission, were not found on guignas and were infrequent on domestic cats. Our results suggest that transmission pathways vary among hemoplasma species and, contrary to our predictions, domestic cats did not appear to be the main driver of hemoplasma infection in guignas in these human-dominated landscapes.

Contrasting phylogeographic pattern among Eudyptes penguins around the Southern Ocean.

Since at least the middle-Miocene, the Antarctic Polar Front (APF) and the Subtropical Front (STF) appear to have been the main drivers of diversification of marine biota in the Southern Ocean. However, highly migratory marine birds and mammals challenge this paradigm and the importance of oceanographic barriers. Eudyptes penguins range from the Antarctic Peninsula to subantarctic islands and some of the southernmost subtropical islands. Because of recent diversification, the number of species remains uncertain. Here we analyze two mtDNA (HVRI, COI) and two nuclear (ODC, AK1) markers from 13 locations of five putative Eudyptes species: rockhopper (E. filholi, E. chrysocome, and E. moseleyi), macaroni (E. chrysolophus) and royal penguins (E. schlegeli). Our results show a strong phylogeographic structure among rockhopper penguins from South America, subantarctic and subtropical islands supporting the recognition of three separated species of rockhopper penguins. Although genetic divergence was neither observed among macaroni penguins from the Antarctic Peninsula and sub-Antarctic islands nor between macaroni and royal penguins, population genetic analyses revealed population genetic structure in both cases. We suggest that the APF and STF can act as barriers for these species. While the geographic distance between colonies might play a role, their impact/incidence on gene flow may vary between species and colonies.

Optimizing recovery after laparoscopic colon surgery (ORAL-CS): effect of intravenous ketorolac on length of hospital stay.

BACKGROUND: The objective of this study was to determine if intravenous ketorolac can reduce ileus following laparoscopic colorectal surgery, thus shortening hospital stay. METHODS: This was a prospective, randomized, double-blind, placebo-controlled, clinical trial of patients undergoing laparoscopic colorectal resection and receiving morphine patient controlled analgesia (PCA) and either intravenous ketorolac (group A) or placebo (group B), for 48 h after surgery. Daily assessments were made by a blinded assistant for level of pain control. Diet advancement and discharge were decided according to strictly defined criteria. RESULTS: From October 2002 to March 2005, 190 patients underwent laparoscopic colorectal surgery. Of this total, 84 patients were eligible for this study and 70 consented. Another 26 patients were excluded, leaving 22 patients in each group. Two patients who suffered anastomotic leaks in the early postoperative period were excluded from further analysis. Median length of stay for the entire study was 4.0 days, with significant correlation between milligrams of morphine consumed and time to first flatus (r = 0.422, p = 0.005), full diet (r = 0.522, p < 0.001), and discharge (r = 0.437, p = 0.004). There we no differences between groups in age, body mass index, or operating time. Patients in group A consumed less morphine (33 +/- 31 mg versus 63 +/- 41 mg, p = 0.011), and had less time to first flatus (median 2.0 days versus 3.0 days, p < 0.001) and full diet (median 2.5 days versus 3.0 days, p = 0.033). The reduction in length of stay was not significant (mean 3.6 days versus 4.5 days, median 4.0 days versus 4.0 days, p = 0.142). Pain control was superior in group A. Three patients required readmission for treatment of five anastomotic leaks (4 in group A versus 1 in group B, p = 0.15). Two of them underwent reoperation. CONCLUSIONS: Intravenous ketorolac was efficacious in improving pain control and reducing postoperative ileus when anastomotic leaks were excluded. This simple intervention shows promise in reducing hospital stay, although the outcome was not statistically significant. The high number of leaks is inconsistent with this group's experience and is of concern.

Laparoscopic resection of gastrointestinal stromal tumors: not all tumors are created equal.

BACKGROUND: Laparoscopic resection has become an accepted approach to gastrointestinal stromal tumors (GISTs), with acceptable early results published in the literature. Long-term recurrence rates, however, are still unclear, and the management of tumors in challenging locations requires exploration. METHODS: A retrospective analysis of all patients undergoing a laparoscopic resection of gastric GIST in our institution between November 1997 and July 2004 was performed. RESULTS: A total of 14 patients with 15 tumors were evaluated, 5 of which were located high on the lesser curve. All the patients had an attempted laparoscopic approach, with the following procedures performed: stapled wedge excision (n = 8), excision and manual sewing technique (n = 4), and distal gastrectomy (n = 1). Overall, there was a 15% (n = 2) conversion rate. Lesions found in the fundus and greater curvature areas were easily resected via simple stapled wedge excision. High lesser curve tumors were more difficult to manage and required a combination of methods for complete excision and preservation of the gastrointestinal junction including intraoperative gastroscopy, excision and manual sewing technique, and reconstruction over an esophageal bougie. There were no postoperative complications, and the length of hospital stay was 4.6 +/- 1.9 days. At a median follow-up period of 46.5 months (mean, 37.4 +/- 26 months), one patient experienced a recurrence (18 months postoperatively), with eventual disease-related death. CONCLUSION: The laparoscopic approach to gastric GIST tumors is safe and associated with acceptable short- and intermediate-term results. High lesser curve GISTs can be safely approached laparoscopically using various techniques to ensure an adequate resection margin without compromise of the GE junction.

Historical dimensions of population structure in a continuously distributed marine species: The case of the endemic Chilean dolphin.

The complementarity of historical and contemporary processes contributes to understanding the genetic structure of continuously distributed marine species with high dispersal capabilities. Cephalorhynchus eutropia, has a continuous coastal distribution with strong genetic differentiation identified by nuclear DNA markers. We explored the historical dimension of this genetic differentiation between northern and southern populations to evaluate phylogeographic structure. Additionally, we conducted mtDNA and microsatellite analyses to detect past and recent demographic changes. The southern population was characterized by lower genetic diversity with a signal of population expansion, likely associated with ice retreat and habitat extension after the Last Glacial Maximum (LGM). In contrast, structure within the northern population was more consistent with stable historical population size. Approximate Bayesian Computation analyses suggested that during the LGM, C. eutropia persisted in the northern area; while the south was colonized by dispersal ~11,000 years ago followed by population expansion. This study shows that Chilean dolphin population structure is consistent with predictions from the Expansion-Contraction biogeographic model, with a poleward post-glacial shift revealed in current genetic structure. The results also confirm the validity of the population units previously identified, demonstrating their historical origin and highlighting the utility of integrating genetic markers with different temporal scale resolutions.

Objective analysis of gastroesophageal reflux after laparoscopic heller myotomy: an anti-reflux procedure is required.

BACKGROUND: Controversy exists over the necessity of performing a concurrent antireflux procedure with a Heller myotomy. We therefore sought to objectively analyze gastroesophageal reflux following laparoscopic Heller myotomy where an antireflux procedure was not performed. METHODS: A prospective database of 66 cases of laparoscopic Heller myotomy performed between November 1996 and June 2002 was reviewed. Previous, concurrent, or subsequent fundoplication was performed in 12 patients; therefore 54 patients without antireflux procedures were available for analysis. Follow-up included symptomatic assessment in 50 patients (93%). Heartburn was assessed on a four-point scale with clinical significance defined as >2 episodes/week. Objective testing, including endoscopy, esophagogram, manometry, and 24-h pH monitoring, was offered to all patients. Objective evidence of reflux was defined as the composite endpoint of positive 24-h pH monitoring or esophagitis on endoscopy. RESULTS: Significant heartburn was reported in 15 of 50 patients (30%). Positive 24-h pH recordings were seen in 11 of 22 patients tested while esophagitis was seen in 13 of 21 patients tested, resulting in objective evidence of reflux in 18 of 30 patients tested (60%). Of these 18 patients, seven did not have significant heartburn. All 12 patients without objective reflux did not have significant heartburn. Therefore, of the 30 patients with objective testing, seven (23%) had objective reflux without subjective heartburn (silent reflux). CONCLUSION: Objective analysis reveals an unacceptable rate of gastroesophageal reflux in laparoscopic Heller myotomy without an antireflux procedure. We therefore recommend performing a concurrent antireflux procedure.

Achalasia developing years after surgery for reflux disease: case reports, laparoscopic treatment, and review of achalasia syndromes following antireflux surgery.

Two case reports demonstrate the paradoxical occurrence of achalasia many years after the successful surgical treatment of gastroesophageal reflux disease (GERD). These patients had remedial surgery laparoscopically. The three types of achalasia syndromes that can follow antireflux surgery are discussed. In type 1, primary achalasia is misdiagnosed as GERD and inappropriate antireflux surgery causes worsening dysphagia immediately after surgery without any symptom-free interval. In type 2, secondary iatrogenic achalasia is seen early after antireflux surgery and is characterized by the presence of stenosis and scar formation at the site of the fundic wrap. Although the motility studies resemble achalasia, the repair needs only to be taken down and refashioned when there is no response to balloon dilatation. In type 3, illustrated by the case reports, primary achalasia follows antireflux surgery after a significant symptom-free interval. There is complete absence of any stenosis or fibrosis of the esophagus and periesophageal tissues at remedial surgery. Moreover, surgical treatment of this condition needs to include esophageal myotomy.

Surgery for peptic strictures.

Benign peptic stricture of the esophagus is a complex disorder which results from persistent gastroesophageal reflux. Its successful management depends on an accurate preoperative evaluation of the stricture and the patient. Surgical management of peptic strictures can be quite effective in relieving the symptoms and halting the pathologic gastroesophageal reflux that accompanies this disorder. This article reviews the general principles of evaluation and surgical treatment of benign peptic esophageal strictures.