Morbidity following thyroid surgery: does surgeon volume matter?

PURPOSE: The aim of our study was to analyze the relationship between surgeon volume and morbidity in patients operated on by surgeons with endocrine specialization (EndS group) and those operated on by general surgeons (GenS group) in a single tertiary institution. METHODS: We present the results of a prospective cohort study of all patients undergoing thyroid surgery in our institution between January 2008 and January 2010, all of whom attended for follow-up for at least 12 months. We assessed pre- and postoperative recurrent laryngeal nerve (RLN) function by laryngoscopy. We monitored serum calcium concentrations in all patients until these values were normal without vitamin D and oral calcium supplementation. RESULTS: We studied 225 patients: 30 in the GenS group (six surgeons performing <5 procedures per surgeon per year) and 195 in the EndS group (two surgeons performing >40 procedures per surgeon per year). The total number of exposed RLN was 46 and 325, respectively. The incidence of RLN palsy persisting beyond 12 months was higher in the GenS group (2/46 vs. 1/325 exposed RLNs, p = 0.04). The incidence of hypocalcaemia persisting beyond 12 months (bilateral procedures) was also higher in the GenS group (3/16 vs. 3/130 patients, p = 0.028). CONCLUSIONS: Morbidity in terms of permanent RLN palsy and hypocalcaemia was less frequent among patients operated on by endocrine-dedicated surgeons. Differences in surgical volume and specialized training in neck endocrine surgery may explain these variations in morbidity.

[Microorganisms and cancer: scientific evidence and new hypotheses]. / Microorganismos y cáncer: evidencias científicas y nuevas hipótesis.

Microorganism involvement in cancer has been known for over a century, and different types of parasites, bacteria and viruses have been associated with oncogenic processes. Among the bacteria, the first recognised was Helicobacter pylori which causes gastric cancer and might be related to extra-gastric cancer in humans. Helicobacter hepaticus has been associated with liver cancers using animal models. Other bacteria, such as Chlamydia psitacii, Borrelia burgdorferi and Streptococcus bovis, have been associated with ocular, skin and colorectal cancers, respectively. Also, a commensal bacterium in the human intestine, Bacteroides fragilis, has been linked, very recently, with colorectal cancer using animal models.

Open and endovascular treatment for pseudoaneurysms of the superior mesenteric artery.

BACKGROUND: Pseudoaneurysms of the superior mesenteric artery are rare, and their natural history is characterized by their tendency to rupture, thereby leading to a high mortality rate. Compared with classic surgical techniques (open), in recent years the possibility of endovascular treatment has increased. RESULTS: We report the cases of two patients with a pseudoaneurysm of the superior mesenteric artery. Each case was successfully treated in a different way: open and endovascular surgery. CONCLUSION: Despite the advantages (less risk for the patient) and good results obtained with endovascular surgery, this cannot completely replace open surgery. The choice of the most appropriate therapeutic option for pseudoaneurysms of the superior mesenteric artery depends on the state of the patient and the characteristics of the lesion. Open and endovascular surgical techniques are complementary, not mutually exclusive, techniques.

Bacterial translocation as a source of Dacron-graft contamination in experimental aortic operation: the importance of controlling SIRS.

BACKGROUND: Several experimental studies have shown the beneficial effects of nitric oxide (NO) in the modulation of the systemic inflammatory response syndrome (SIRS). Nitric oxide is involved in and affects almost all stages in the development of inflammation. We have attempted to ascertain whether the nitric oxide donor molsidomine prevents aortic graft contamination through control of the SIRS and a decrease in bacterial translocation (BT). METHODS: Twenty-four mini-pigs were divided into 4 groups. The animals were subjected to suprarenal aortic/iliac cross-clamping (for 30 minutes) and by-pass with a Dacron-collagen prosthetic graft impregnated in rifampicin. Groups: 1) sham (aortic dissection alone); 2) cross-clamping and bypass; 3) hemorrhage of 40% of total blood volume before cross-clamping and by-pass; and 4) the same as in group 3 but also including the administration of the NO donor molsidomine (4 mg/kg) 5 minutes before cross-clamping. VARIABLES: 1) bacteriology of mesenteric lymph nodes (MLN), kidney, blood, and prosthesis; 2) serum TNF-alpha (ELISA); and 3) iNOS expression in kidney and liver (Western blot). RESULTS: Aortic cross-clamping with or without hemorrhage was associated with BT in 80% and 100% of the animals, respectively. About 86% of the bacteria isolated in the graft were also present in MLN. This contamination coincided with an increase in TNF-alpha and with a greater expression of iNOS. Molsidomine administration decreased TNF-alpha and iNOS, decreased BT (from 100% to 20% of the animals), and decreased graft contamination (from 83% to 20%). CONCLUSIONS: The present model induces high levels of BT and SIRS, both acted as sources of contamination for the implanted Dacron graft. Molsidomine administration decreased the presence of bacteria in the graft by controlling BT and modulating SIRS.

[Surgical access routes in enteral nutrition]. / Vías de acceso quirúrgico en nutrición enteral.

There are many known routes of access to the digestive tract for enteral nutrition (EN) and significant advances have been made in recent years. Administration techniques and nutritional products have also improved. Placement of these systems may be temporary or permanent. Indications often overlap. If feasible, the enteral route is preferred over the parenteral route. When enteral nutrition will last < or = 6 weeks, nasoenteral tubes are the best option. In NE > or = 6 weeks, enterostomy tubes are indicated and the procedure of choice is percutaneous endoscopic gastrostomy. Postpyloric access should be considered in patients with a high risk of aspiration. Finally, needle catheter jejunostomy during interventions in the upper gastrointestinal tract is the ideal technique for initiating early EN. All these techniques continue to be valid and the choice of procedure will be determined by the patient's clinical status and the experience of the team. The present article is divided into two parts. In the first part, surgical access techniques for EN, their indications and contraindications and the most frequent complications related to the technique, the care of the stoma and the intubation material are analyzed. In the second part, we report data from our personal experience of the various techniques we have performed and describe the patients, results and complications. A total of 287 procedures were performed: 48 surgical gastrostomies, 40 using the technique of Fontan or Stamm, and 8 Janeway gastrostomies; 27 of these procedures were permanent. There were 169 jejunostomy catheters, with a mean dwelling time of 29.05 +/- 21.9 days, and 72 double lumen nasojejunal tubes.

Application of horizontal staircase electrophoresis in agarose minigels to the random intergenic spacer analysis of clinical samples.

The random intergenic spacer analysis is a recently developed technique for the study of microbial populations. The bacterial intergenic spacer (ITS) is located between 16S rRNA and 23S rRNA genes and presents different length and sequence among bacterial species. Therefore, the amplicons can be separated by electrophoresis commonly performed at low voltage during several hours. Although this technique is especially useful for unculturable microorganisms, it has not been applied before to clinical sample analysis. As these samples have a limited number of bacterial species, the size of the gels may be reduced to facilitate their handling and to reduce the running time. To obtain maximum separation among the ITS bands, we analysed in this work different electrophoretical conditions including staircase electrophoresis, a technique based on the application of several voltage steps. The results obtained showed a different behaviour of the electrical resistance during the performance of submarine horizontal and vertical staircase electrophoresis. In the first case the resistance decreased during most of the running time whereas in the second case it increased. Here, we show that the performance of horizontal staircase electrophoresis reduces the running time more than 80% with respect to conventional electrophoresis at low voltages. This procedure was applied to the separation of ITS bands from bacterial DNA present in a tissue from a vocal cord biopsy. The sequencing of these bands allowed their identification. This new procedure may be very useful in the rapid diagnosis of bacteria present in human, animal and plant tissues.

Postoperative evolution of inflammatory response in a model of suprarenal aortic cross-clamping with and without hemorrhagic shock. Systemic and local reactions.

Surgery of the abdominal aorta generates a systemic inflammatory response (SIR), a source of operative morbidity-mortality. In the present work we attempted to evaluate the evolution of SIR in an experimental model that simulates elective and urgent surgery on the abdominal aorta. Fifteen mini-pigs divided into three groups were used. The animals were subjected to suprarenal aortic/iliac clamping and bypass with a Dacron-collagen prosthetic graft. Groups were as follows: (1) sham (only aortic dissection); (2) clamping and bypass; (3) hemorrhage of 40%, pre-clamping, and bypass. Determinations included (1) tumor necrosis factor-alpha (TNF-alpha) interleukin (IL)-1beta, IL-6, IL-10, interferon-gamma; (2) myeloperoxidase (MPO), superoxide anion (SOA), superoxide dismutase (SOD), and malondialdehyde (MDA); (3) nitrites; (4) iNOS, (5) cell adhesion molecules (ICAM-1, VCAM-1) at 24 hours, 48 hours, and on day 7; and (6) NFkappaB at 48 hours. Our results point to an increase in all inflammatory variables, corroborated by their molecular regulators such as the expression of CAMs, iNOS, and NFkappaB. The alterations tended to normalize by day 7, after reperfusion. The results point to the great importance of SIR at all levels (molecular, nuclear, cellular, and systemic) in situations such as elective and urgent abdominal aorta surgery and the role that control of this response could represent for the future of vascular surgery.

P- and E-selectin blockade can control bacterial translocation and modulate systemic inflammatory response.

Bacterial translocation is an important phenomenon in clinical medicine and leads to an increase in patient morbidity and mortality by multiple organ failure. The selectin family plays an important role in the pathogenesis of inflammation, causing an increase in leukocyte-endothelium interactions and inducing a greater leukocyte's migration. This study considered the effect of a sulfo derivative of Sialyl-Lewis(X), GM 1998-016, that will block the P- and E-selectins interaction with a ligand, the Sialyl-Lewis(X), valuing the modulation of the systemic inflammatory response and the induced translocation. Seventy-five Wistar male rats were injected intraperitoneally with Zymosan A and treated with different doses of GM 1998-016 according to study groups. Measurements of values of qualitative and quantitative microbiology, neutrophil infiltration (myeloperoxidase), oxygen free radicals (superoxide anion, superoxide dismutase, catalase, and gluthatione peroxidase), and cytokines (tumor necrosis factor-alpha and interleukin-1beta) were taken at different times after Zymosan administration. A significant decrease of bacterial translocation, both local (MLN) and systemic (p < .05), was observed, with a decrease in the neutrophil infiltration (p < .001), the oxygen free radicals production (p < .01) and the studied cytokines (p < .01). In conclusion, GM 1998-016 showed a protective effect in an in vivo experimental model of bacterial translocation, downregulating the inflammatory response and the leukocyte-endothelium interactions.

Exogenous nitric oxide modulates the systemic inflammatory response and improves kidney function after risk-situation abdominal aortic surgery.

OBJECTIVE: Renal impairment is a very frequent complication of aortic surgery requiring prolonged suprarenal clamping, especially if it is associated with previous hemorrhage. The aim of this study was to assess the beneficial effect of the administration of a nitric oxide (NO) donor on renal function through a modulation of the systemic inflammatory response in a model of abdominal aortic surgery. METHODS: Twenty-five minipigs were divided into five groups. Under anesthesia, the animals were subjected to suprarenal aortic-iliac clamping (for 30 minutes) and bypass with a Dacron-collagen prosthetic graft impregnated in rifampicin, with or without associated hemorrhage (40% of total blood volume). Prophylaxis with cefazolin was implemented. The five groups were (1) the sham group (only aortic dissection), (2) the clamping and bypass (C) group, (3) hemorrhage preclamping and bypass (H+C) group, (4) the same as group C but with the administration of the NO donor molsidomine (4 mg/kg intravenously) (C+NO group), (5) the same as the H+C group but with the administration of the NO donor molsidomine (4 mg/kg intravenously) (H+C+NO group). The following were determined: (1) kidney function (serum creatinine), (2) serum cytokines (tumor necrosis factor alpha [TNF-alpha] and interleukin-10 [IL-10]); (3) neutrophil infiltration (myeloperoxidase [MPO]) in the kidney, (4) oxygen free radicals (superoxide anion [SOA] and superoxide dismutase [SOD]) in the kidney, (5) serum nitrites, (6) soluble and kidney tissue cell adhesion molecule (soluble intercellular adhesion molecule-1 [sICAM-1], soluble vascular cell adhesion molecule-1 [sVCAM-1], intercellular adhesion molecule-1 [ICAM-1], and vascular cell adhesion molecule-1 [VCAM-1]), (7) inducible nitric oxide synthase (iNOS) in the kidney, and (8) nuclear factor-kappaB (NF-kappaB) in the kidney. Determinations were made during ischemia at 15 minutes post-reperfusion; at 24, 48, and 72 hours; and on day 7. RESULTS: The different insults used in the experimental model led to deterioration in kidney function and an increase in the systemic (and renal) inflammatory response at all levels investigated. Treatment with an NO donor, both with and without associated hemorrhage, reduced the inflammatory response at the systemic (TNF-alpha and IL-10) and kidney (MPO, SOA, and SOD) levels, normalizing kidney function. Likewise, exogenous administration of NO improved the excessive production of NO (nitrites) via iNOS. This was also reflected in a reduction in CAMs and of NF-kappaB expression. The hypotension induced by molsidomine was transitory and did not elicit hemodynamic repercussions. CONCLUSION: In our experimental model, prophylactic treatment with the NO donor molsidomine regulates the systemic inflammatory response and minimizes damage at the kidney level. Clinical Relevance The importance of this article resides in the fact that an experimental study that clarifies the effect of the donors of NO under circumstances as similar as possible to those of the human clinic, such as aortic surgery under hypovolemic shock (ruptured aortic aneurysm) have been little studied, most of these studies being performed in rodents without bypass. Using a model with one or two simultaneous insults (aortic clamping with/without previous hemorrhage) that is very similar to the human clinical situation (abdominal aortic rupture), we confirm the findings of previous work related to the beneficial effects of NO donors.

Exogenous nitric oxide can control SIRS and downregulate NFkappaB.

BACKGROUND: Nitric oxide (NO) participates in inflammation and affects almost all steps of its development. Several experimental studies have unveiled the beneficial effects of NO through modulation of the Systemic Inflammatory Response Syndrome (SIRS). In this sense, in the present work we attempted to evaluate the beneficial effects of exogenous NO and its levels of action (biochemical and cellular) in a model of SIRS induced by two sequential insults. MATERIALS AND METHODS: Dacron graft implantation (first insult) and subsequent administration of Zymosan A (second insult) in Wistar rats. The animals were divided into four groups: 1) No manipulation (Basal); 2) Laparotomy (L) + mineral oil (Sham); 3) L + Graft-Zymosan (GZ) (Control); and 4) L + GZ + NO (Assay). Determinations: Survival, TNF-alpha, SOA, ICAM-1, and NFkappaB. RESULTS: The model established (Control) induced a mortality rate of 20%. Also, it significantly increased the levels of TNF-alpha (P <0.001) and SOA (P <0.01), ICAM-1 expression, and NFkappaB levels (P <0.05). Treatment with NO reduced mortality to 0%, significantly decreasing TNF-alpha (P <0.001) and SOA (P <0.01) levels, ICAM-1 expression, and NFkappaB levels (P <0.05). CONCLUSION: The exogenous administration of NO before the two sequential insults controlled SIRS at biochemical level (TNF-alpha, SOA) and at cellular level (transcription) in a lasting manner. The cascade-like interrelationship of both levels and the study design do not allow us the pinpoint the key to its modulation.

Evaluation of multiparameter flow cytometry for the detection of breast cancer tumor cells in blood samples.

We comparatively evaluated different cytokeratin (CK) reagents analyzed by flow cytometry (FCM) for the identification of the best combination of DNA/CK staining for detecting minimal numbers of breast cancer cells in peripheral blood (PB). In 59 primary breast cancer tumors, we comparatively analyzed the reactivity for up to 6 different anti-CK reagents using multiparameter FCM: anti-CK7, anti-CK20, anti-pan-CK, anti-CK8/CK18, anti-CK8, and anti-CK18. Afterward, dilutional experiments of Michigan Cancer Foundation (MCF)7 breast cancer cells in PB were performed, and the sensitivity of a DNA/CK18 staining was evaluated. Our results showed that anti-CK18 reagents were those providing the brightest and more sensitive staining for primary breast cancer tumor cells by FCM. Dilutional experiments of MCF cells in PB showed that the DNA/anti-CK18 double staining was highly specific for the identification of epithelial cells; its sensitivity ranged between 10(-6) and 10(-7) (detection of 1 tumor cell among 10(6) to 10(7) nucleated blood cells). Combined assessment of DNA cell contents and reactivity for CK18 by FCM is a sensitive method for the specific identification of breast cancer cells in PB.

Her-2/neu gene amplification in familial vs sporadic breast cancer. Impact on the behavior of the disease.

We compared the incidence of Her-2/neu amplification in patients with and without a family history of breast cancer and correlated gene status with clinicobiologic and prognostic features in sporadic and familial cases. Of 108 patients, 28.7% had gene amplification. Among 96 cases with family history information available, 28 had an affected first-degree relative. The gene was amplified more frequently in familial than in sporadic cases (13/28 [46%] vs 14/68 [21%]; P = .01). Among familial cases, amplification was associated with adverse clinicobiologic features (poorly differentiated tumors [P = .05], larger tumors [P = .05], more lymph nodes involved [P = .04], and DNA aneuploid [P = .02] and highly proliferative tumors [P = .005]), and the relapse (P = .02) and disease-related death (P = .05) rates were higher than in cases without amplification. Among sporadic cases, amplification was not associated with significantly different disease features, except for a higher incidence of DNA aneuploid tumors (P = .01), percentage of S-phase tumor cells (P = .006), and lower proportion of estrogen (P = .001) and progesterone (P = .002) receptors. Her-2/neu amplification was observed more frequently among patients with a family history of breast cancer, in whom it was associated with adverse clinicobiologic features and a worse clinical outcome.

Numerical abnormalities of chromosomes 17 and 18 in sporadic colorectal cancer: Incidence and correlation with clinical and biological findings and the prognosis of the disease.

BACKGROUND: In recent years important information has accumulated on the genetic alterations present in colorectal tumors. However, thus far few studies have analyzed the impact of numerical abnormalities of chromosomes 17 and 18, which carry the p53 and DCC plus SHAD4/DPC4 genes involved in colorectal cancer, on the clinical and biological behaviors of the disease. METHODS: With the use of interphase fluorescence in situ hybridization (FISH), we analyzed the incidence of numerical abnormalities of chromosomes 17 and 18 in a series of malignant colorectal tumors and explored its potential association with clinicobiological behavior and the prognosis of the disease. For this purpose, 94 consecutive patients newly diagnosed with colorectal cancer were analyzed. In all cases, FISH analyses of the number of copies and nuclei of chromosomes 17 and 18 were performed in interphase nuclei with the use of double stainings. For all patients, information on age, sex, tumor size, Dukes' stage, tumor localization, DNA ploidy status, and the proportion of S-phase tumor cells was recorded. Median follow-up was 38 months. RESULTS: Numerical abnormalities of chromosomes 17 and 18 were present in most patients with colorectal cancer (57% and 52%, respectively). Gains of chromosome 17 and monosomy 18 were found in 51% and 29% of cases, respectively, and they were the most frequent individual abnormalities for each chromosome. The simultaneous analysis of the number of copies of both chromosomes in the same cell showed that, in most cases displaying numerical abnormalities for these chromosomes, two or more different tumor cell clones were present. From a clinical point of view, numerical abnormalities of chromosome 17, especially monosomy 17, were associated with a significantly higher incidence of rectal tumors (P = 0.001) and Dukes' stage D (P = 0.02) and a lower median of disease-free survival among patients who underwent curative surgery (P = 0.05), as compared with diploid cases. In addition, cases with an altered number of copies of chromosome 17 showed a higher incidence of DNA aneuploidy (P = 0.0001) and a greater proportion of S-phase cells (P = 0.001) by flow cytometry. In contrast, no clear association was found between the presence of numerical abnormalities of chromosome 18 and clinicobiological disease characteristics, except for a higher incidence of DNA aneuploidy by flow cytometry (P = 0.001) and a lower median of disease-free survival (P = 0.06). Multivariate analysis showed that numerical abnormalities of chromosome 17, but not of chromosome 18, are an independent prognostic factor for predicting disease-free survival in patients with colorectal cancer. CONCLUSIONS: Numerical abnormalities of chromosomes 17 and 18 were relatively common findings in patients with colorectal cancer, with chromosome 17 being associated with a higher incidence of tumors localized to the rectum and a worse clinical outcome. Cytometry Part B (Clin. Cytometry) 51B:14-20, 2003.

Systemic inflammatory response induced by dacron graft and modulation by antimicrobial agents: experimental study.

BACKGROUND: The purpose of this work was to evaluate the effect that different antimicrobial agents and different forms of administering them would have over a systemic inflammatory response (SIR) induced by an intraperitoneally implanted collagen-coated Dacron graft. MATERIALS AND METHODS: Thirty-six male Wistar rats were randomly allocated into six groups of 6 animals each: (I) control, (II) "sham," (III) graft but no antibiotic, (IV) graft plus systemic cefazolin, (V) graft plus locally applied gentamicin, and (VI) graft soaked in rifampicin. After 72 h, mesenteric lymph nodes, liver, kidney, and the implanted graft were sent to the microbiology laboratory and cultured for aerobic and anaerobic organisms in order to evaluate bacterial translocation. Serum cytokines (IL-1beta and TNF-alpha), myeloperoxidase activity in liver and kidney, and superoxide anion and superoxide dismutase activities in liver were also determined to evaluate the level of SIR. RESULTS: Microbiologic and biochemical data indicated that intraperitoneal implantation of a collagen-coated Dacron graft induced a significant (P < 0.05) bacterial translocation and a high inflammatory response, both of which decreased significantly with antibiotic treatment regardless of the means of administration (P < 0.05). CONCLUSIONS: The present experimental model shows that the antibiotics used, in different means of administration, reduce bacterial translocation and behave as modulators of the SIR induced by an intraperitoneal collagen-coated Dacron graft.

[Barrett esophagus and surgery]. / La cirugía y el esófago de Barrett.

The Barrett esophagus is the substitution of the esophagus distal epithelium (scaly) by another one of columnar type (intestinal metaplasia). It is due to the gastroesophageal or duodenogastric reflux and other genetic and gotten factors. In the diagnosis it is essential to discover the existence and grade of dysplasia which constitute the pre-malignant stage of the adenocarcinoma by which vigilance is very important. The treatment is the same as the one of gastroesophageal reflux and there is no agreement about the advantages of the medical and the surgical treatment. The medication (IBP) is effective against the acid reflux but doesn't control the duodenogastric in contrast to the surgery (antireflux techniques) which is also cheaper and in recent studies it seems to control the dysplasia progress.