Superexchange-mediated ferromagnetic coupling in two-dimensional Ni-TCNQ networks on metal surfaces.

We investigate the magnetic coupling of Ni centers embedded in two-dimensional metal-coordination networks self-assembled from 7,7,8,8-tetracyanoquinodimethane (TCNQ) molecules on Ag(100) and Au(111) surfaces. X-ray magnetic circular dichroism measurements show that single Ni adatom impurities assume a spin-quenched configuration on both surfaces, while Ni atoms coordinating to TCNQ ligands recover their magnetic moment and exhibit ferromagnetic coupling. The valence state and the ferromagnetic coupling strength of the Ni coordination centers depend crucially on the underlying substrate due to the different charge state of the TCNQ ligands on the two surfaces. The results suggest a superexchange coupling mechanism via the TCNQ ligands.

[Dysphagia. Are swallowing sounds diagnostically useful?]. / Dysphagie Sind Schluckgeräusche diagnostisch nutzbar?

The origin and importance of swallowing sounds in dysphagia have been discussed in previous research. Those studies report a general similarity in the sound patterns of different swallowing actions. The current paper confirms this. In addition, the origin of swallowing sound patterns is examined more closely. Finally, we simultaneously analyzed the swallowing sounds of healthy voluntary subjects and patients with swallowing disorders using X-ray cinematography. Videoendoscopy was also done. As expected, we found a variety of sound sequences differing from those of healthy subjects. Patients with tracheal tubes or cannulae constitute a special group whose swallowing sounds give additional information about the act of swallowing.

[Twenty-five years of experience in incisional hernia surgery. A comparative retrospective study of 432 incisional hernia repairs]. / 25 Jahre Erfahrung in der Narbenhernienchirurgie. Eine vergleichende, retrospektive Studie an 432 Narbenbruchoperationen.

INTRODUCTION: Incisional hernia surgery in Germany is changing from conventional techniques to mesh implantation. The relevance of different factors such as surgical technique, mesh material, and patient-related parameters concerning the outcome following mesh repair is still under debate. METHODS: In a comparative retrospective study of 432 incisional hernia operations on 348 patients we analyzed 11 autodermic hernioplasties, 241 Mayo procedures,and 180 mesh repairs over a 25-year time period. In addition to the quality of life following mesh implantation,the prognostic relevance of demographic, pre- and intraoperative parameters, surgical technique, mesh material, and the surgeon's experience were subjected to both univariate and multivariate analysis. RESULTS: With a mean follow-up of 9.7+/-8.8 years, the rate of major complications following mesh repair was 9% in contrast to 3% after the Mayo procedure (p=0.091). The sublay technique revealed less complications compared to the onlay procedure (p=0.016). The total recurrence rate following the overlapping Mayo repair was 37% in contrast to 15% after mesh implantation (p=0.001), with a significant superiority of the sublay technique over the inlay technique (p=0.043). The rate of recurrences and complications after autodermic hernioplasty was 72% and 36%,respectively. After mesh repair, 86% of the patients were better satisfied with the results after Marlex mesh compared to GoreTex (p=0.016). Mesh size was the only significant prognostic factor concerning quality of life following mesh implantation. The complication rate was determined significantly by the patients' risk factors, size of hernia, surgical technique, and the surgeon's experience, whereas the rate of recurrences was significantly influenced by the parameters obesity (BMI >25), size of hernia,and surgical experience. The recurrence rate decreased significantly with the surgeon's experience: a minimum of 16 mesh repairs led to a recurrence rate of less than 10%. CONCLUSIONS: Only the mesh repair revealed acceptable recurrence rates with high patient comfort. The sublay technique is superior to onlay concerning the complication rate, whereas the autodermic hernioplasty and inlay techniques are obsolete. The material of choice is polypropylene. The most important prognostic factor following mesh repair is the surgeon's experience.

[Clinical presentation and prognosis of brain stem infarcts. An evaluation of the Stroke Databank of the German Stroke Foundation]. / Klinische Präsentation und Prognose von Hirnstamminfarkten. Eine Auswertung der Schlaganfall-Datenbank der Stiftung Deutsche Schlaganfall-Hilfe.

Due to the great variety of clinical classification systems and syndromes, a representative overview of the etiology and prognosis of brain stem infarctions is missing. From the German Stroke Data Bank we therefore investigated 455 patients with visible brainstem infarction on cerebral imaging in comparison to patients with other infarct localizations. Follow-up after 3 and 12 months assessed functional outcome and recurrence of cerebral ischemia. Of 455 patients with acute brainstem infarction, 115 had additional infarctions in other vascular territories. In the remaining 340 patients with isolated brainstem infarction, the classification was: small vessel disease in 36.2%, macroangiopathy in 22.6%, and cardioembolism in 11.2%. After 3 months, 10% of the patients with isolated brainstem infarction had died and 55.6% were functionally independent. Mortality was 43.5% in patients with combined brainstem infarction. Our study highlights the frequency of small vessel disease as well as the relatively favorable prognosis in isolated brainstem infarction and preserved consciousness.

Laparoscopic fundoplication.

BACKGROUND: The effectiveness of laparoscopic Nissen fundoplication (LNF) was assessed in patients with chronic gastroesophageal reflux disease (GERD) using pH study and different quality-of-life indexes. We correlated both types of data and hypothesised that improvement in quality of life following LNF does not necessarily correlate with improvement in pH values. METHODS: Seventy patients presenting with typical symptoms of GERD (14 with Barrett's esophagus) underwent LNF between May 1997 and December 2000. All patients were evaluated both prior to and 3 months after surgery using 24-h pH study, endoscopy, and a validated quality-of-life questionnaire. RESULTS: Following LNF, reflux was reduced to normal in all but six patients. Howevers despite persistent reflux, the Gastrointestinal Quality of Life Index (GQLI), of these six patients improved postoperatively from 79.5 +/- 12.2 to 111.7 +/- 8.3. These results correlate with those of patients who had normal postoperative pH studies-namely, 88.5 +/- 19.3 to 112 +/- 16.7. There was no difference in quality-of-life improvement between patients with Barrett's esophagus and those without it. CONCLUSION: There is only a weak correlation between quality-of-life assessment and pH study. Because the patient's quality of life is likely to improve following LNF, an objective means parameter of assessing the effectiveness of antireflux surgery, such as pH study or endoscopy, is recommended.

[Problem of recurrent incisional hernia after mesh repair of the abdominal wall]. / Zur Problematik des Narbenhernienrezidivs nach Netzplastik der Bauchwand.

INTRODUCTION: Depending on the surgical technique, mesh material and follow-up, the figures for recurrences of incisional hernia vary from 0 to 31%. What are the reasons for recurrences, and which options exist for more successful therapy? METHODS: Fourteen operations for recurrences after mesh repair of incisional hernias were analyzed retrospectively and correlated with a literature review of the years 1990-2000. RESULTS: An inadequate surgical technique is the main reason for recurrences after the use of polypropylene or polyester, but with PTFE, it is instead the properties of the material. In our patients we found central mesh recurrences. The first results with laparoscopic technique are very promising. CONCLUSIONS: Open incisional hernia mesh repair should be performed with the sublay technique, preferably with polypropylene; the use of polyester can be recommended only with reservations and the use of PTFE ought to be limited to very few indications. The entire incision should always be prepared with safe fixation of the mesh and wide overlap of the hernia. Recurrences after polypropylene implantation can be treated with additional mesh; concerning PTFE, a different material is recommended. A final evaluation of laparoscopic mesh repair cannot be assessed yet.

[Standardized sublay technique in polypropylene mesh repair of incisional hernia. A prospective clinical study]. / Standardisierte Polypropylennetzplastik der Narbenhernie in Sublay-Technik. Eine prospektive klinische Studie.

INTRODUCTION: With the introduction of meshes to support hernia repairs the recurrence rates were reduced from 50% to less than 10%. Special complications such as scar plates with restriction of the mobility of the abdominal wall, pain and fistula formation are described. METHODS: In a prospective study trial 38 patients with incisional hernia were treated with Marlex mesh repair in the standard sublay technique. RESULTS: Within a mean follow-up period of 3 years most of the patients were free from pain and very satisfied. Two recurrences (5.2%) occurred and 2 hematomas (5.2%) had to be removed surgically. CONCLUSIONS: Using a standard operation technique with the mesh in sublay position, even with heavy-weight Marlex mesh, good clinical results can be achieved compared to published findings. To our surprise we found two central recurrences through the mesh.

Central mesh recurrence after incisional hernia repair with Marlex--are the meshes strong enough?

The use of biomaterial meshes in the repair of incisional abdominal wall hernias is now widely accepted internationally. The introduction of synthetic meshes to achieve tension-free repair has led to a satisfactory reduction in the recurrence rate to less than 10%. However, the use of such biomaterials can result in the occurrence of undesirable complications such as increased risk of infection, seromas, restriction of the abdominal wall and failure caused by mesh shrinkage. Additionally, at the time of writing there is much discussion concerning the potential risk of a persistent foreign body reaction directly associated with the meshes with regard to possible malignant transformation. As such, the trend seems to be toward the use of lighter meshes utilizing less non-absorbable material. One particular novel mesh theoretically capable of guaranteeing the necessary mechanical stability uses 70% less biomaterial. Against this background, we report a central mesh recurrence through the mesh following incisional hernia repair with a Marlex mesh. To our knowledge, this is the first description of a central mesh recurrence, and we discuss a possible mechanism with particular emphasis on the required abdominal wall forces both physiologically and after incisional hernia repair.

'Cross-section gastroenterostomy' in patients with irresectable periampullary carcinoma.

BACKGROUND: The most frequent complication following gastroenterostomy (GE) for gastric outlet obstruction is delayed gastric emptying (DGE), which occurs in roughly 20% of patients. There is evidence that DGE may be linked to the longitudinal incision of the jejunum and that a transverse incision (cross-section GE) may decrease the incidence of DGE following GE. PATIENTS AND METHODS: In contrast to the orthodox GE, the jejunum is severed transversely up to a margin of 1.5 cm at the mesenteric border and the anastomosis is created with a single running suture. A Braun anastomosis is added 20-30 cm distally to the GE. Patients were followed prospectively with special regard to the occurrence of DGE. RESULTS: Between 1 August 1994 and 1 August 1998, 25 patients underwent cross-section GE, mostly because of an irresectable periampullary carcinoma. Eight patients exhibited clinical signs of gastric outlet obstruction preoperatively, while in 17 the GE was performed on a prophylactic basis. A biliary bypass was added in 15 patients. There was no disruption of the GE, but one patient died in hospital (4%). The nasogastric tube was withdrawn on the first postoperative day (range 0-6 days), a liquid diet was started on the fifth day (range 2-7 days) and a full regular diet was tolerated at a median of 9 days (6-14 days).The incidence of DGE was 4%: only the single patient who died fulfilled the formal criteria for DGE. DISCUSSION: In contrast to orthodox GE, DGE seems to be of minor clinical importance following cross-section GE. As the technique is easy to perform, is free of specific complications and leads to a low incidence of DGE, it should be considered as an alternative to conventional GE.

[Traumatic pulmonary hernia]. / Die incarcerierte traumatische intercostale Lungenhernie.

The traumatic pulmonary hernia is a rare and uncommon observation. We report a case of a 52-year-old patient who had a car accident. Beside multiple polytraumatic injuries we were able to diagnose an incarcerated pulmonary hernia. Hernia size, incarceration and the respiratory insufficiency of the patient necessitating immediate surgical intervention. We relocated the hernia into the chest and stabilized the thoracic wall. The postoperative course was uneventful.