Obesity increases the surgical complexity and risk of recurrence after midline primary ventral hernia repair: results on 2307 patients from the French Society of hernia surgery (SFCP-CH) registry database.

PURPOSE: Obesity is a known risk factor of recurrence after hernia surgery, but available data often concern pooled cases of primary and incisional hernia, with short follow-up. We aimed to analyze the impact of severe obesity (BMI ≥ 35 kg/m2) on the results of midline primary ventral hernia repair (mPVHR), in comparison with non-severely obese patients. METHODS: Data were extracted from a multicentric registry, in which patients' data are consecutively and anonymously collected. We conducted a retrospective comparative study on patients with severe obesity (sOb) versus non-severely obese patients (non-sOb), who underwent surgery, with a minimal 2-year follow-up after their mPVHR. RESULTS: Among 2307 patients, 267 sOb and 2040 non-sOb matched inclusion criteria. Compared with non-sOb, sOb group gathered all the worse conditions and risk factors: more ASA3-4 (39.3% vs. 10.2%; p < 0.001), symptomatic hernia (15.7% vs. 6.8%; p < 0.001), defect > 4 cm in diameter (24.3% vs. 8.8%; p < 0.001), emergency surgery (6.1% vs. 2.5%; p = 0.003), and Altemeir class > 1 (9.4% vs. 2.9%; p < 0.001). Laparoscopic IPOM was used more often in sOb patients (40% vs. 32%; p = 0.016), but with smaller Hauters' ratio (46 vs. 73; p < 0.001). Compared with the non-sOb, the rate of day-case surgery was lower (48% vs. 68%; p < 0.001), the surgical site occurrences were significantly more frequent (6.4 %vs. 2.5%; p < 0.001). The main outcome, 2-year recurrence, was 5.9% in the sOb vs. 2.1% (p = 0.008), and 2-year reoperations was 3% vs. 0.3% (p = 0.006). In the adjusted analysis, severe obesity was an independent risk factor for recurrence [OR = 2.82, (95%CI, 1.45; 5.22); p = 0.003]. CONCLUSION: In patients with severe obesity, mPVHR is technically challenging and recurrence rate is three times higher than that of non-severely obese patients.

Cover crop mixture diversity, biomass productivity, weed suppression, and stability.

The diversity-productivity, diversity-invasibility, and diversity-stability hypotheses propose that increasing species diversity should lead, respectively, to increased average biomass productivity, invasion resistance, and stability. We tested these three hypotheses in the context of cover crop mixtures, evaluating the effects of increasing cover crop mixture diversity on aboveground biomass, weed suppression, and biomass stability. Twenty to forty cover crop treatments were replicated three or four times at eleven sites using eighteen species representing three cover crop species each from six pre-defined functional groups: cool-season grasses, cool-season legumes, cool-season brassicas, warm-season grasses, warm-season legumes, and warm-season broadleaves. Each species was seeded as a pure stand, and the most diverse treatment contained all eighteen species. Remaining treatments included treatments representing intermediate levels of cover crop species and functional richness and a no cover crop control. Cover crop seeding dates ranged from late July to late September with both cover crop and weed aboveground biomass being sampled prior to winterkill. Stability was assessed by evaluating the variability in cover crop biomass for each treatment across plots within each site. While increasing cover crop mixture diversity was associated with increased average aboveground biomass, we assert that this was the result of the average biomass of the pure stands being drawn down by low biomass species rather than due to niche complementarity or increased resource use efficiency. At no site did the highest biomass mixture produce more than the highest biomass pure stand. Furthermore, while increases in cover crop mixture diversity were correlated with increases in weed suppression and biomass stability, we argue that this was largely the result of diversity co-varying with aboveground biomass, and that differences in aboveground biomass rather than differences in diversity drove the differences observed in weed suppression and stability.

Vecuronium in the myasthenic patient.

The use of vecuronium in six patients with myasthenia gravis undergoing thymectomy is described the train-of-four twitch technique was used to monitor neuromuscular function. The first two patients received an initial dose of 0.02 mg/kg and incremental doses of 4 micrograms/kg, which is in the order of one fifth of that normally used. Satisfactory depression of the first twitch of the train-of-four, however was not obtained and, therefore, in the remaining four patients the doses were doubled. At this dose satisfactory depression of the first twitch was achieved. Neostigmine 5.0 mg produced adequate reversal of residual neuromuscular blockade and the train-of-four twitch response recovered to normal levels. With reduced dosage and with careful neuromuscular monitoring, vecuronium can be used safely in the myasthenic patient.

Atracurium in the myasthenic patient.

The use of the new competitive muscle relaxant, atracurium, is described in five myasthenic patients presenting for thymectomy. With an initial dose of 0.1 mg/kg, that is approximately one-fifth of that normally used, and incremental doses of 0.02-0.04 mg/kg, satisfactory clinical conditions were achieved. Neuromuscular function was monitored throughout using the train-of-four mechanical twitch response, and residual neuromuscular blockade was reversed satisfactorily at the end of the procedure with neostigmine 5.0 mg. A marked increase in the magnitude of the first twitch of the train-of-four to greater than control levels, accompanied by pronounced fade, was found on reversal. In reduced dosage and with careful neuromuscular monitoring, atracurium is safe to use in the myasthenic patient.

Anaesthesia for transcervical thymectomy in myasthenia gravis.

A modified technique of total intravenous anaesthesia was used in the management of 22 patients with myasthenia gravis of varying severity undergoing therapeutic transcervical thymectomy. The relatively short-acting intravenous hypnotics, Althesin and etomidate were compared for induction of anaesthesia and for maintenance as a supplement to 50% nitrous oxide in oxygen. Moderately high doses (20 or 25 micrograms/kg) of the potent, synthetic opiate, fentanyl provided analgesia and a level of respiratory depression sufficient to facilitate control of respiration. The induction of anaesthesia was rapid and smooth, completed in under 5 minutes. Reflex response to surgical stimulation was suppressed for extremely variable periods. Complete recovery of consiousness, or adequate spontaneous respiration and of muscle tone was readily achieved, but was more rapid after Althesin (p less than 0.05). Postoperative problems were few. It is suggested that this technique of anaesthesia can provide optimum operating conditions with rapid, complete recovery and consequently low morbidity; the primary requirements of anaesthesia for therapeutic thymectomy.

Cervical thymectomy in the treatment of myasthenia gravis.

A retrospective review of 22 patients undergoing cervical thymectomy for myasthenia gravis is presented. Their ages ranged from 19 to 67 years. The male and female ratio as well as the severity of illness prior to operation were similar to other reported series. All patients were evaluated from the standpoint of clinical response to thymectomy, and the number and dosage of anti-myasthenic drugs required after operation. There was a statistically significant improvement in clinical status in the immediate postoperative period (P less than 0.05) and a further significant improvement was noted at six months (P less than 0.05). In addition, significant reductions in postoperative drug therapy were noted (P less than 0.05). Complications from cervical thymectomy were minimal and mortality was zero. An attempt was made to correlate histological findings with clinical results. Comparison is made to other series in the literature and the advantages of the cervical technique as the initial surgical approach are described. The data presented support a useful role for cervical thymectomy in the treatment of myasthenia gravis.