Is pre-term labour associated with periodontitis in a Danish maternity ward?

OBJECTIVES: To reveal differences in periodontal status and presence of subgingival bacteria in a Scandinavian population of women with pre-term birth compared with women who delivered at term. MATERIALS AND METHODS: Twenty-one women with pre-term labour (before week 35) and 33 women with term labour (between weeks 38 and 41) were included in this case-control study. Periodontal measurements included plaque index (PlI), probing pocket depth (PPD) and bleeding on probing (BOP). Inter-proximal distances from the cemento-enamel junction (CEJ) to the marginal bone crest (MBC) were measured on bitewing radiographs. In 31 patients (16 cases and 15 controls) the subgingival plaque was analysed using "checkerboard" DNA-DNA hybridization. RESULTS: Differences between the two examined groups were found related to "Twin births" (p=0.0064) and "Smokers" (p=0.03). None of the periodontal measurements showed any association. Significant differences were found concerning presence of Tannerella forsythensis, Treponema denticola, Peptostreptococcus micros, Streptococcus intermedius, Streptococcus oralis, Streptococcus sanguis and Capnocytophaga ochracea but when defining sites with >10(5) bacteria as heavily colonized, no statistical difference was found between the two groups. CONCLUSION: A relation between pre-term birth and periodontitis was not revealed in the present study.

Favorable histologic findings and tensile strength at 14 years in knitted polyester aortofemoral and femoropopliteal grafts in the same patient.

Patent right and left limbs of an aortobifemoral knitted polyester graft and a patent left femoropopliteal graft, both implanted for 14 years, were removed 40 hr postmortem from a 63-year-old man. Healing studies were performed, using routine and immunocytochemistry staining scanning electron microscopy (SEM), and transmission electron microscopy (TEM) on multiple samples taken from sites sufficiently far from the anastomoses to avoid pannus healing. Evaluation by weight-elongation comparison with a fresh graft demonstrated that structural stability and strength were well preserved. Anastomoses were patent with no remarkable intimal hyperplasia. There was no thrombus on the flow surface of either graft. Histologic studies of these grafts revealed uniform through-wall tissue ingrowth and extensive patches of endothelial cells scattered over the flow surface, confirmed by factor VIII, SEM, and TEM. These findings document that long-term stable tensile strength and healing with flow surface endothelialization can be attained with knitted polyester grafts in the human.

Cryopreserved femoral vein grafts for difficult hemodialysis access.

Improved survival of patients with renal failure has led to the need for complex angioaccess procedures. The use of cryopreserved femoral vein for angioaccess when prosthetic arteriovenous grafts (AVG) could not be placed, owing to infection or the loss of conventional angioaccess sites from multiple AVG failures, was prospectively evaluated. Forty-eight cryopreserved femoral vein AVGs were placed in 44 patients. Thirty-eight (82%) of the cryopreserved femoral vein AVGs were placed for infection, whereas the other 10 (18%) were placed for multiple graft failures with compromised venous outflow. Even with implantation of the cryoveins into infected patients, there were no cryopreserved femoral vein AVG infections. The 1-year primary graft patency rate was 49% and the secondary graft patency rate was 75%. During the same time interval, 68 prosthetic brachial artery-to-axillary vein AVGs were placed. The 1-year primary and secondary patency rates for the prosthetic AVGs were 65 and 78%, respectively. In this study the overall patency rate of the cryopreserved femoral vein AVGs was similar to that for the PTFE AVGs (p = 0.519). In conclusion, the cryopreserved femoral vein proved useful in difficult angioaccess cases. The lack of infection after cryovein implantation around an infected area shows promise for salvaging an angioaccess site that would otherwise have been abandoned.

Model studies of the flow in abdominal aortic aneurysms during resting and exercise conditions.

Pulsatile flow in abdominal aortic aneurysm (AAA) models has been examined in order to understand the hemodynamics that may contribute to growth of an AAA. The model studies were conducted by experiments (flow visualization and laser Doppler velocimetry) and by numerical simulation using physiologically realistic resting and exercise flow conditions. We characterize the flow for two AAA model shapes and sizes emulating early AAA development through moderate AAA growth (mean and peak Reynolds numbers of 362 < Re(mean) < 1053 and 3308 < Re(peak) < 5696 with Womersley parameter 16.4 < alpha < 21.2). The results of our investigation indicate that AAA flow can be divided into three flow regimes: (i) Attached flow over the entire cycle in small AAAs at resting conditions, (ii) vortex formation and translation in moderate size AAAs at resting conditions, and (iii) vortex formation, translation and turbulence in moderate size AAAs under exercise conditions. The second two regimes are classified in the medical literature as disturbed flow conditions that have been correlated with atherogenesis as well as thrombogenesis. Thus, AAA disturbed hemodynamics may be a contributing factor to AAA growth by accelerating the degeneration of the arterial wall. Our investigation also concluded that vortex development is considerably weaker in an asymmetric AAA. Furthermore, turbulence was not observed in the asymmetric model. Finally, our investigation suggests a new mode of transition to turbulence: vortex ring instability and bursting to turbulence. The transition process depends on a combination of the pulsatile flow conditions and the tube cross-sectional area change.

Endothelium on the flow surface of human aortic Dacron vascular grafts.

PURPOSE: We have previously observed endothelium on two human vascular prostheses explanted under optimal conditions for flow surface preservation. In this study we sought to further verify the hypothesis that endothelialization can occur on clinical grafts and that it can be detected in specimens that have been promptly removed and properly preserved in a timely manner. METHODS: We studied 29 aortic grafts. Of these, 11 Dacron bypass grafts were in a condition suitable for analysis with light microscopy and immunocytochemistry staining, and scanning and transmission electron microscopy. RESULTS: Three grafts had endothelium beyond the pannus, identified by factor VIII/ vWF, Ulex europaeus agglutinin, and collagen IV positivity. Specimen A, a knitted 6-year implant, was preserved by embalming 3 hours after the patient's death and had a firmly attached outer capsule with fibroblasts, collagen, giant cells, and microvessels in the interstices. Specimen B, a woven 18-year implant, was retrieved at reoperation and immediately fixed in 10% formalin; it had no outer capsule and no tissue ingrowth. Specimen C, a woven 7-year implant, was removed and fixed 5 hours after the patient's death; it had a firmly attached outer capsule but no tissue ingrowth beyond the outer portion of the wall. CONCLUSIONS: The rapidity with which the specimens were fixed probably enabled identification of endothelium. These findings suggest that endothelialization of synthetic arterial grafts may occur more frequently in human beings than previously recognized.

The influence of shape on the stresses in model abdominal aortic aneurysms.

Presence of a small abdominal aortic aneurysm (AAA) often presents a difficult clinical dilemma--a reparative operation with its inherent risks versus monitoring the growth of the aneurysm, with the accompanying risk of rupture. The risk of rupture is conventionally believed to be a function of the AAA bulge diameter. In this work, we hypothesized that the risk of rupture depends on AAA shape. Because rupture is inevitably linked to stress, membrane theory was used to predict the stresses in the walls of an idealized AAA, using a model which was axisymmetric and fusiform, with the ends merged into straight opened-ended tubes. When the stresses for many different shapes of model AAAs were examined, a number of conclusions became evident: (i) maximum hoop stress typically exceeded maximum meridional stress by a factor of 2 to 3 (ii) the shape of an AAA had a small effect on the meridional stresses and a rather dramatic effect on the hoop stresses, (iii) maximum stress typically occurred near the inflection point of a curve drawn coincident with the AAA wall, and (iv) the maximum stress was a function--not of the bulge diameter---but of the curvatures (i.e. shape) of the AAA wall. This last result suggested that rupture probability should be based on wall curvatures, not on AAA bulge diameter. Because curvatures are not much harder to measure than bulge diameter, this concept may be useful in a clinical setting in order to improve prediction of the likelihood of AAA rupture.

Conventional versus high-porosity polytetrafluoroethylene grafts: clinical evaluation.

In baboons, nonreinforced (unwrapped) 60 microns internodal distance polytetrafluoroethylene grafts form a complete endothelial lining within 2 weeks by capillary ingrowth through the wall. Smooth muscle cells then grow under the endothelium and proliferate to form a complete neointima. To determine if spontaneous endothelialization of these grafts can also occur in humans, 10 above-knee femoropopliteal grafts composed of equal lengths of 60 and 30 microns polytetrafluoroethylene were placed in eight patients. These grafts were reinforced (wrapped) for human use. Because biopsy of the grafts was not possible, endothelialization was assessed noninvasively by 111In-labeled platelet imaging 1 week and 3 months after surgery. There was no difference in indium uptake between 60 and 30 microns segments at either time. Histologic sections were available from 60 microns segments of two patients who underwent operation for graft thrombosis. Capillary ingrowth was seen in these grafts, but it rarely extended more than half the distance from the outside of the graft to the lumen. Smooth muscle cells were not seen on the flow surface, indicating that a neointima had not formed. These findings demonstrate that capillary ingrowth can occur in 60 microns grafts in humans but does not produce an endothelial lining. The failure to endothelialize is perhaps a result of inadequacy of angiogenesis in adult humans or retardation of capillary ingrowth by the reinforcing wrap.

Colon infarction after ruptured abdominal aortic aneurysm.

Colon infarction is a lethal complication of ruptured abdominal aortic aneurysm. We compared multiple anatomic, hemodynamic, and clinical features in 25 patients with ruptured abdominal aortic aneurysm who suffered colon ischemia and 25 initial survivors of ruptured abdominal aortic aneurysm in whom this complication did not develop. Prior impressions notwithstanding, preoperative shock or volume administration did not correlate with the development of colon ischemia, nor did aneurysm location, cross-clamp site, graft type, or inferior mesenteric artery patency. However, patients with colon ischemia had a significantly lower perioperative cardiac output and were significantly more likely to have received alpha-adrenergic vasoconstrictor agents. Seventeen patients (68%) with colon ischemia died compared with nine patients (36%) without colon ischemia. Perioperative maintenance of cardiac output and avoidance of alpha-adrenergic vasopressor agents are critical elements in prevention of this lethal complication.

Injuries to the portal triad.

We reviewed the management and clinical course of 21 patients with extrahepatic injuries to the portal triad seen over the past 11 years at a Level I trauma center. These represented only 0.21% of patients with multiple trauma admitted during this time. Portal triad injury was never specifically diagnosed preoperatively. Extrahepatic bile duct injury occurred in 4 patients, portal vein injury in 14, and hepatic artery injury in 7; 3 patients had combined injuries. Eleven patients (52%) died, all due to uncontrolled hemorrhage from either an injured portal vein or associated intra-abdominal injuries. Management of the bile duct injuries included drainage alone, bile duct ligation, and Roux-Y hepaticojejunostomy. Survivors of portal vein injury were managed with lateral venorrhaphy. Ligation of the hepatic artery appeared to be optimal for injuries incurred by this vessel. Complications necessitating reoperation or percutaneous drainage procedures were encountered in 8 of 10 surviving patients (80%). Injuries to the portal triad are uncommon, difficult to diagnose, and technically challenging. Mortality is most directly related to uncontrolled intraabdominal hemorrhage, and salvage requires rapid control of bleeding as the first treatment priority.

Brain tryptophan hydroxylation in the portacaval shunted rat: a hypothesis for the regulation of serotonin turnover in vivo.

Regional and whole-brain tryptophan-hydroxylating activity and serotonin turnover were investigated in portacaval shunted (PCS) rats using an in vivo decarboxylase inhibition assay. To saturate tryptophan hydroxylation with amino acid substrate, rats were administered a high dose of tryptophan 1 h prior to analysis of brain tryptophan, 5-hydroxytryptophan, serotonin, and 5-hydroxyindoleacetic acid. The analysis revealed, as expected, higher brain concentrations of tryptophan and 5-hydroxyindoles and increased serotonin synthesis rate in PCS rats as compared with shamoperated controls. Saturating levels of brain tryptophan were achieved in both PCS and sham animals after exogenous tryptophan administration. The tryptophan load resulted in increased brain serotonin turnover in all regions and in whole brain compared with rats that did not receive a tryptophan load. Tryptophan-loaded PCS rats showed increased brain serotonin turnover compared with tryptophan-loaded sham rats. Regionally, this supranormal tryptophan-hydroxylating activity was most pronounced in the mesencephalon-pons followed by the cortex. It is concluded that, at least in the PCS rat, brain tryptophan hydroxylation is an inducible process. Since it is known that brain tissue from PCS rats undergoes a redox shift toward a reduced state and that the essential cofactor tetrahydrobiopterin is active in tryptophan hydroxylation only when present in its reduced form, it is hypothesized that this is the reason for the supranormal tryptophan-hydroxylating activity displayed by the PCS rats. The hypothesis further suggests that alterations in tetrahydrobiopterin availability may serve as a mechanism by which brain tryptophan hydroxylation, and therefore serotonin turnover, can be regulated with high sensitivity in vivo.

Bleeding gastroesophageal varices: gastric vein embolization after partial portal decompression.

Shunts that decompress the portal vein are effective in the treatment of bleeding esophageal varices. Use of large-caliber portacaval shunts, however, results in the complete decompression of the portal system and the risk of subsequent development of hepatic encephalopathy. Use of small-caliber portacaval shunts results in mild portal hypertension and less frequent hepatic encephalopathy but may increase the risk of recurrent bleeding. Thirty-three patients underwent angiography after partial decompression portacaval shunting (median trans-shunt pressures, 8 mm Hg). Embolization of residual varices, noted in 13 patients, was performed. Results included one complication with no sequelae and no bleeding a mean of 13 months after the procedure was performed. Trans-shunt embolization of esophageal varices effectively prevents bleeding varices after partial portal decompression.

Arterial injury complicating knee disruption. Third place winner: Conrad Jobst award.

Because dislocation of the knee (DK) is accompanied by a substantial risk of popliteal artery injury, the importance of arteriography in ruling out occult arterial damage in such patients is well accepted. However, because antecedent DK cannot be ruled out in a trauma victim presenting only with severe knee ligamentous disruption (LD), we have routinely performed arteriography in all patients presenting with grossly unstable knees, whether or not DK is present. To evaluate this policy we reviewed the records of 30 patients with either DK (n = 19) or severe LD (n = 11). There was no significant difference between DK and LD in the frequency of major (22% vs 18%) or minor (38% vs 36%) vascular abnormalities. We also found that Doppler pressure measurements were highly predictive of major arterial trauma in patients in whom it was used. We conclude that arterial injury should be ruled out in all trauma victims with severe knee ligament disruption, whether or not actual joint dislocation is present.

Multicenter trial of cadexomer iodine to treat venous stasis ulcer.

In a crossover study designed to judge the efficacy of the topical polymeric starch iodophore, cadexomer iodine, in accelerating the healing of venous stasis ulcers, 75 patients were prospectively randomly assigned to receive either cadexomer iodine or standard treatment. The control treatment consisted of a standard saline wet-to-dry compressive dressing. The patients improved with either treatment: ulcers healed more than twice as rapidly using cadexomer iodine (n = 38) as with standard therapy (n = 37) (P = .0025). Ulcers treated with cadexomer iodine showed trends toward less pain, exudate, pus, and debris, and a more rapid development of granulation tissue. Twelve patients crossed over from control treatment to the use of cadexomer iodine because of a failure to heal, but no patients switched to control therapy from the use of cadexomer iodine (P = .01). Except for occasional mild local burning in wounds treated with cadexomer iodine, no adverse effects were noted with either regimen.

Indomethacin and cerebral blood flow in premature infants treated for patent ductus arteriosus.

Central blood flow (CBF) was estimated by an intravenous 133-xenon technique in six preterm infants before and after administration of indomethacin for closure of patent ductus arteriosus. CBF fell in all infants (range 12%-40%), the mean fall was 24% (P less than 0.005). Though none of the infants showed signs of impaired cerebral function during or following the injections, the results do not indicate whether or not the use of indomethacin is a potential hazard.

Esophageal transection fails to salvage high-risk cirrhotic patients with variceal bleeding.

A small proportion of portal hypertensive patients with acute variceal bleeding do not respond to medical management and require emergency control of hemorrhage, yet are not candidates for shunt surgery. Transgastric esophageal transection and stapling of the esophagus has been suggested as a rapid, simple means to halt variceal bleeding in such high-risk patients. This should theoretically allow a hemorrhage-free interval for resuscitation and improvement in metabolic and cardiopulmonary status before definitive shunt surgery. We tested this hypothesis in 10 high-risk patients with variceal bleeding who underwent transection of the esophagus, sometimes with splenectomy and coronary vein ligation, over a 4 year period. In our experience, esophageal transection in high-risk patients with variceal bleeding controlled acute variceal hemorrhage, was neither rapid nor free of technical misadventures, was associated with a high rate of serious postoperative complications resulting in death in nearly all patients, and consistently failed to result in sufficient metabolic improvement to permit shunt surgery.

Open tibial fractures with associated vascular injuries: prognosis for limb salvage.

Open tibial fractures complicated by limb-threatening vascular injuries present an infrequent but difficult management problem. Twenty-three cases were reviewed with an ultimate amputation rate of 61% (22% primary, 39% delayed). Crush injuries, segmental tibial fractures, and revascularization delays of greater than 6 hours were associated with a bad outcome. Guidelines for primary amputation (crushing injuries, delay in revascularization, segmental tibial fractures) are proposed and implications of limb salvage are reviewed.

The impact of patients with chronic character pathology on a hospital inpatient unit.

Inpatient psychiatric facilities are admitting an increasing number of young patients with chronic character pathology. Hospitals must explore the impact these patients have on the treatment facility and the risks inherent in their treatment, including the possibility of decreased milieu specificity, increased staff regression, and loss of cost-effectiveness. These risks are system responses that go beyond individual staff countertransferences. Possible remedies include refined indications for inpatient psychiatric treatment, tailoring of milieu functions to fit individual patient needs, explicit accountability of administrative and supervisory structures, and involvement of families in the formation of the initial treatment alliance.