Technical Risk Factors Research Articles

Ätiopathologische und pathophysiologische Faktoren der Narbenhernie

Etiopathological and Pathophysiological Aspects of Incisional Hernias Due to an incidence of up to 20% the development of an incisional hernia is the most frequent complication of general surgery leading to an enormous socioeconomic impact. Despite developments in surgical techniques used for closure of the abdominal wall, improvements in technical skills were not able to eliminate this common complication. In recent years, alterations of the extracellular matrix, particularly collagen, have been the focus of research. The importance of a biological approach can be verified by analyzing related risk factors (i. e. age, gender, infection, exogenous factors). This article reviews the currently known technical and biological risk factors leading to the development of an incisional hernia.

Temporary arterial occlusion in the repair of ruptured intracranial aneurysms: an analysis of risk factors for stroke.

This study was performed to further elucidate technical and patient-specific risk factors for perioperative stroke in patients undergoing temporary arterial occlusion during the surgical repair of their aneurysms. One hundred twelve consecutive patients in whom temporary arterial occlusion was performed during surgical repair of an aneurysm were retrospectively analyzed. Confounding factors (inadvertent permanent vessel occlusion and retraction injury) were identified in six cases (5%) and these were excluded from further analysis. The demographics for the remaining 106 patients were analyzed with respect to age, neurological status, aneurysm characteristics, intraoperative rupture, duration of temporary occlusion, and number of occlusive episodes; end points considered were outcome at 3-month follow up and symptomatic and radiological stroke. Overall 17% of patients experienced symptomatic stroke and 26% had radiological evidence of stroke attributable to temporary arterial occlusion. A longer duration of clip placement, older patient age, a poor clinical grade (Hunt and Hess Grades IV-V), early surgery, and the use of single prolonged clip placement rather than repeated shorter episodes were associated with a higher risk of stroke based on univariate analysis. Intraoperative aneurysm rupture did not affect stroke risk. On multivariate analysis, only poorer clinical grade (p = 0.001) and increasing age (p = 0.04) were significantly associated with symptomatic stroke risk.

Scleral perforation during retrobulbar and peribulbar anesthesia: risk factors and outcome in 50 000 consecutive injections

Purpose To measure the frequency of scleral perforation and identify related risk factors during local anesthetic injection for intraocular surgery. Setting Multispecialty eye hospital. Methods All patients ( n = 50 000) having retrobulbar (26 857) or peribulbar (23 143) injections at the King Khaled Eye Specialist Hospital were reviewed. Cases of scleral perforation were analyzed for potential technical and ophthalmic risk factors, management of injuries, and visual and anatomic outcomes. Mean follow-up was 14.4 months (range 8 to 24 months). Results Seven (0.014%) needlestick injuries were identified, all of which had posterior staphyloma as the only identifiable risk factor. Applying a previously measured prevalence of 10.7% for posterior staphyloma in our surgery patients gave a scleral perforation rate of 0.13% (7 of 5350) for staphylomatous eyes. All perforated globes had originally planned cataract extraction within 8 weeks of injury. Additional management consisted of observation (2 cases), cryotherapy (2 cases), and vitreoretinal procedures for retinal detachment (3 cases) and subretinal hemorrhage (1 case). At last follow-up, all retinas were attached and 3 cases (42.8%) had a visual acuity of worse than 20/160. Both cases requiring multiple retinal detachment surgeries developed proliferative vitreoretinopathy and poor visual acuity. Conclusions Eyes with posterior staphyloma sustained needlestick injuries at a rate of 1 in 760 compared with 0 injection perforations in more than 44 000 nonstaphylomatous eyes.

The “first generation” of endovascular stent-grafts for patients with aneurysms of the descending thoracic aorta

Objective: Our goal was to determine whether endovascular stent-grafting is feasible and effective for patients with aneurysms of the descending thoracic aorta. Methods: Starting in July 1992, we conducted a prospective, uncontrolled clinical trial in 103 patients (mean age 69 years [range 34-89 years]) who underwent endovascular treatment of aneurysms of the descending thoracic aorta using a custom-fabricated, self-expanding stent-graft device. Follow-up was 100% complete and averaged 22 months. Sixty-two patients (60%) were judged not to be reasonable candidates for a conventional “open” surgical procedure. Results: Complete thrombosis of the aneurysm was ultimately achieved in 86 (83%) patients. The early mortality rate was 9% ± 3% (±70% CL). Multivariable analysis revealed that myocardial infarction or stroke was linked with a higher likelihood of early death ( P = .001). Early serious complications included paraplegia in 3% ± 2% and stroke in 7% ± 3%. Actuarial survival estimates at 1 year and 2 years were 81% ± 4% and 73% ± 5% (±1 SE), respectively; being judged not to be a surgical candidate portended a higher probability of death ( P = .003). According to the intent-to-treat principle, “treatment failure” (including all late sudden unexplained deaths) occurred in 38 patients; 53% ± 10% of patients were free from treatment failure at 3.7 years. Stent-graft related complications occurred commonly and were linked with several anatomic, technical, and patient-related risk factors. Conclusions: This 5-year clinical trial involving use of a “first generation” device indicates that endovascular stent-grafting of descending thoracic aortic aneurysms is feasible with acceptable medium-term results. More refined, commercially developed devices available today offer less traumatic and more precise stent-graft deployment; these major technical advantages, coupled with important lessons we have learned over time and better patient selection, should be associated with more salutary clinical results in the future. (J Thorac Cardiovasc Surg 1998;116:689-704)

Temporary vessel occlusion for aneurysm surgery: risk factors for stroke in patients protected by induced hypothermia and hypertension and intravenous mannitol administration

Temporary vessel occlusion is an effective technique used by microvascular surgeons to facilitate dissection and permanent clipping of cerebral aneurysms; however, several questions remain regarding the overall safety of this technique. To identify technical and patient-specific risk factors for perioperative stroke, the authors examined a series of patients in whom induced hypertension and mild hypothermia and intravenous mannitol administration were used as protection during temporary vessel occlusion for aneurysm clipping. The study comprises a nonconcurrent prospective analysis of 132 consecutive aneurysm clippings performed with the aid of temporary vascular occlusion and a specific antiischemic anesthetic protocol at the Massachusetts General Hospital from 1991 to 1993. Factors studied included duration of the temporary clip application, number of occlusive episodes, patient age and neurological status, presence of preoperative subarachnoid hemorrhage (SAH), and intraoperative aneurysm rupture ("forced" temporary clipping), as well as whether proximal vessel occlusion or complete aneurysm trapping was used. In a univariate analysis, patient age, intraoperative aneurysm rupture, temporary clipping lasting more than 20 minutes, clipping between the 4th and 10th day after SAH, and multiple clipping episodes were all significantly associated with stroke outcome. Multivariate logistic regression revealed that intraoperative aneurysm rupture (relative risk 5.6, p = 0.02) and a duration of temporary clip application that lasted more than 20 minutes (relative risk 9.4, p = 0.04) were independently associated with stroke outcome. Overall, 5.2% of the patients had postoperative clinical strokes. Based on their findings the authors conclude that temporary clipping is a safe adjunct to aneurysm surgery, particularly when the duration of clipping is short.

Measuring the fetal kidney with ultrasonography

To establish a normal range of measurements for the external and internal dimensions of the fetal kidney and, if possible, to correlate these measurements with gestational age. The external and internal dimensions of the fetal kidney were measured in 810 women selected on the grounds of obstetric, fetal or technical risk factors from a consecutive series of 1136 women attending the ante-natal ultrasonography clinic of a district general hospital. Post-natal data were obtained from medical records on 1122 newborns. The maximum of pairs of renal measurements was used for analysis. Measurements were cross-sectional in 347 cases and longitudinal in 463. The total number of measurement episodes was 2294. External renal dimension and gestational age were closely related, enabling accurate growth centile charts to be constructed. The correlation between renal pelvic dimension and gestational age was weak. The maximum dimension of the renal pelvis at any gestational age in 92.7% of fetuses was < 5 mm. Using longitudinal measurements, 6.5% of cases with a renal pelvic dimension of < 5 mm at the first scan measured > or = 5 mm at a subsequent scan, but 53.3% with a dimension of > or = 5 mm at the first scan also measured > or = 5 mm at the subsequent scan. It is possible to assess the growth and size of the fetal kidney according to gestational age but this does not apply to the renal pelvis. A renal pelvic dimension of > 5 mm at any gestational age is unusual and dilatation beyond this level should prompt a detailed post-natal urological investigation.

Analysis of risk factors involved in reoperation for mitral and tricuspid valve disease

Of 196 consecutive patients who had heart valve operations within the period of June 9, 1971, to Oct. 31, 1972, 125 patients with mitral and combined mitral and tricuspid valve surgery were retrospectively matched in order to analyze the risks of closed- and open-heart valve reoperation. Forty-seven patients had transventricular mitral valvotomy, 58 had mitral valve replacement, and the remaining 20 patients had mitral and tricuspid valve surgery. Of the analyzed operative difficulties and postoperative complications, tissue adhesions and bleeding were significantly higher in patients with one and two previous cardiac operations. However, neither of these complications influenced the operative mortality rate which was more dependent on the extent of myocardial damage than the technical risk factors expected after a second or a third operation.