Complex inguinal hernia repairs.

INTRODUCTION: Complex inguinal hernia treatment is a challenge for general surgeons. The gold standard for the repair of inguinal hernias is the Lichtenstein repair (anterior approach). However, when multiple recurrent hernias or giant hernias are present, it is necessary to choose different approaches because the incidence of poor results increases. There are many preperitoneal approaches described in the literature. For example: (a) open procedure-Nyhus and Stoppa (b) laparoscopic technique-transabdominal pre-peritoneal (TAPP) and totally extraperitoneal (TEP). In this study, we show how we repair complicated cases using open access in huge unilateral or bilateral, recurrent, or multiple recurrent inguinal hernias. METHODS: The present study includes the period from November 1993 through December 2007. One hundred and eighty-eight patients, divided into 121 with unilateral hernias and 67 with bilateral hernias, totaling 255 inguinal hernia repairs, were treated by the Nyhus or Stoppa preperitoneal approach, depending on whether they were unilateral or bilateral. We used progressive preoperative pneumoperitoneum for oversize inguinal hernias in all patients. RESULTS: Orchiectomy was necessary on only two occasions. Despite the repair complexity involved, we had only two known recurrences. The mortality was zero and the morbidity was acceptable. CONCLUSIONS: We conclude that an accurate open preperitoneal approach using mesh prosthesis for complex inguinal hernias is safe, with very low recurrent rates and low morbidity. Progressive preoperative pneumoperitoneum for giant hernias was shown to be an important factor in accomplishing good intraoperative and immediate postoperative results.

Operative ultrasonography in the biliary tract during pregnancy.

Operative roentgenographic cholangiography entails problems during pregnancy because of the hazard of radiation to the fetus and mother. In 450 biliary tract operations in which real-time B-mode operative ultrasonography was performed, five were for diseases of the biliary tract during pregnancy. Operative ultrasound correctly revealed non-palpable stones in the gallbladder in one patient and in the common bile duct in three patients. Furthermore, operative ultrasound provided anatomic information, such as dilation or stenosis of the common bile duct. Of seven possible occasions in which roentgenography would customarily be expected to be performed, operative cholangiography was used only once. Thus, ultrasound significantly reduced the number of operative roentgenographic studies. Operative ultrasonography was not associated with any complications and significant time delays. It is concluded that operative ultrasonography can replace operative roentgenographic cholangiography as a screening procedure for gallbladder and common duct calculi at biliary tract operations during pregnancy.

Ultrasonic detection of red cell aggregation immediately preceding blood clotting.

High-resolution ultrasonic imaging of circulating blood was used to study the relation between red cell aggregation and blood clotting in vitro. A reversible increase in echogenicity produced by red cell aggregation occurred in moving heparinized blood as shear rate was decreased. We induced clotting of the heparinized blood by administration of protamine. At both low (1.6 sec-1) and moderate (22.6 sec-1) mean shear rates, transient homogenous increased echogenicity indicative of red cell aggregation preceded blood clotting. In separate experiments, we established that protamine can cause increased echogenicity due to red cell aggregation which can be reversed by adding heparin to circulating suspended red cells in the absence of clotting factors. Presumably, these effects of protamine and heparin are due to electrostatic bonding involving red cell surfaces. We conclude from these studies that red cell aggregation precedes clotting of heparinized blood by protamine at low and moderate shear rates.

[Operative ultrasonography of the brain and spinal cord pathology].

B-mode real-time ultrasound using 5 or 7.5 MHz transducer has been employed during 21 operations for brain pathology and spinal cord lesions. Ultrasonic scanning was performed at the following operations: 10 brain tumors (4 glioblastomas multiforme, 2 astrocytomas, 1 medulloblastoma, 2 metastatic tumors), 2 brain cysts (arachnoid, epidermoid), 1 tuberculous abscess, 3 cerebral hematomas: 2 spinal cord tumors (malignant melanoma, glioma), 2 syringomyelias, 1 posterior longitudinal ligament thickening. Operative ultrasound was useful prior to dural incisions and particularly for subcortical lesions. In addition, ultrasound provided assistance at spinal cord surgery. Our experience has been reviewed and summarized in this report in terms of specific usefulness of assistance of this method which has proven helpful to the neurosurgeons. The types of assistance provided by operative ultrasonography include: Location of dural incision. Localization of brain and spinal cord lesions prior to biopsy. Diagnosis which has not been made preoperatively (e.g. necrosis or cystic area in tumor). Consistency of each lesion (e.g. solid or cystic, necrosis, loculation). Size, extent and depth of brain tumor, cyst, abscess and hematoma. Presence and extent of spinal cord syrinx. Relation of tumor to spinal cord and dura. Access route for biopsy and drainage (avoiding critical areas such as motor strip). Exclusion of bleeding or hematoma following biopsy. Confirmation of the effectiveness of drainage or resection of lesions. Relationship between pathology and surrounding anatomic structures. A number of important assistance by the utilization of ultrasound during neurological surgery have been identified.(ABSTRACT TRUNCATED AT 250 WORDS)

Criteria for using imaging ultrasound during brain and spinal cord surgery.

Imaging ultrasonography was performed during 23 brain and five spinal cord operations with real-time B-mode instruments. Criteria for the utilization of ultrasound at neurosurgical procedures were identified in terms of assistance in the diagnosis or better definition of lesions. The diagnosis criteria were detection and exclusion. Because of the accuracy of preoperative imaging, usually little further help was provided by operative ultrasonography in detecting previously totally unknown abnormalities or excluding lesions found on positive studies. The definition criteria were localization, distinction of tissue features, and assessment of spatial relations. Operative ultrasonography was most useful when applied on the basis of these definition criteria. Operative ultrasonography was considered to be useful in 22 of 28 operations (79 per cent) in which it assisted in exposing, accessing, and extirpating disease.

The effects of temperature on blood flow ultrasonic echogenicity in vitro.

An explanation of the mechanism of ultrasonic echogenicity in flowing blood is proposed based upon an in vitro study that indicates a causal relation between red cell aggregation and these echoes. Echogenicity was measured in vitro at 37 degrees, 24 degrees, and 0 degree C as blood flow shear rates were varied. Echogenicity increased at higher temperatures and lower shear rates. The directions of changes in blood echogenicity exactly paralleled previously known changes in red cell aggregation resulting from changes in temperature. The authors consider this to be further evidence that red cell aggregation is an important cause of low-intensity echoes observed in clinical ultrasonography of the heart and circulation.

Experimental assessment of imaging variables associated with operative ultrasonic and radiographic cholangiography.

The comparative accuracies of operative ultrasonic and radiographic cholangiography to detect biliary calculi 1 mm in diameter inside tubes of different calibers were assessed. One hundred eighty tubes were prepared to provide ten tubes each for the following variables: three sizes of tubes (6, 13, 20 mm), three concentrations of contrast material (15, 30, 60 per cent), and presence or absence of calculi. Real-time B-mode ultrasound scans with a single gain and time gain compensation (TGC) setting were performed and contrast radiographs were also made at a single optimal exposure. Sixty ultrasonic and 180 radiographic examinations were studied. All ultrasonic interpretations were correct regardless of size of tube. Under optimal conditions, radiographic interpretations were also correct. However, whereas a single gain and TGC setting was applicable for all ultrasound examinations, variable contrast concentrations were required for the best radiographic imaging. Optimal radiographic contrast concentrations differed with tube diameters. The authors conclude that both ultrasonic and radiographic contrast imaging are highly accurate for the detection of small biliary calculi. However, contrast radiography requires stricter optimization of variables needed to provide the high accuracy. Thus, operative ultrasonography may be a more practical and reliable diagnostic procedure because of high sensitivity and greater ease of performance and interpretation.

Critical factors in the image clarity of operative cholangiography.

To evaluate image clarity in operative cholangiography with changing radiographic variables, in vitro experiments were performed in which 1-mm radiographically nonopaque biliary calculi in tubes were examined. Variables changed in these studies were tube caliber (6, 13 and 20 mm), contrast concentration (15, 30, and 60%), X-ray exposures (1, 2, 4, 8, 16, 32, 64, and 128 mAs) and location of calculi (central or peripheral). Sensitivity for the detection of calculi and the clarity of contrast radiographic images depended upon these variables. Reduced contrast concentration or increased radiographic exposure were needed for large caliber tubes. Central small calculi required more exposure than peripheral calculi. Practical inferences from these studies can be summarized as guidelines for performing operative cholangiography: (1) Surgeons should become aware of exposure settings used on the radiographic equipment in the operating room. In particular, the milliampere-seconds-setting is an important variable. (2) Normal size and slightly enlarged ducts should be injected with 30% radiographic contrast. (3) Ducts which are 20 mm or more in diameter should be injected with 15% contrast. (4) Variable radiographic exposures may be necessary to demonstrate centrally and peripherally located calculi, especially for small calculi in large ducts.

Comparative accuracy of operative ultrasonography and cholangiography in detecting common duct calculi.

Operative ultrasonography and operative radiographic cholangiography were compared for diagnostic effectiveness with regard to their ability to screen the common bile duct for the presence of calculi. We performed real-time B-mode ultrasonography and cholangiography using two injections of contrast material. In 350 patients, 349 ultrasonic and 285 cholangiographic examinations were performed with technically satisfactory results. The sensitivity, specificity, efficiency, and predictability of a negative test were at a high and comparable level for the two diagnostic procedures. However, the predictability of a positive test for ultrasonography of 91.8% was significantly greater (P less than 0.02) than the predictability of 73.2% for cholangiography. Since predictability of a positive test is based on common duct exploration rather than presumptive evidence of a clinical course, this test may be more valid than the other measures to determine diagnostic effectiveness. The advantages of ultrasonography, which are superior accuracy, favorable image qualities, reduced invasiveness, increased safety, avoidance of contrast material, and lower cost, were contrasted with the problems of ultrasonography, which included a slow learning curve for performance and interpretation of the technique and the limited availability of dedicated ultrasound equipment for surgical operations. We concluded that the advantages outweighed the problems and that operative ultrasonography of the common duct warrants wider application in clinical surgery.

Red cell aggregation as a cause of blood-flow echogenicity.

The role of red cell aggregation as a cause of ultrasonic echogenicity in flowing blood was evaluated by in vitro experiments using fresh human blood. Blood was circulated in tubes of varying diameter (12 mm to 6 mm). In all experiments, echogenicity increased as blood approached static conditions. Echogenicity was greater in tubes with a larger diameter over the same range of blood velocity. However, echogenicity in tubes of various diameters was the same when evaluated in terms of shear rate. Thus, shear rate and not velocity is the flow condition that determines echogenicity. Since shear rate determines the degree of red cell aggregation, while other conditions affecting red cell aggregation (hematocrit, erythrocyte membrane conditions, and plasma macromolecules) are held constant, we conclude that these results provide additional evidence that red cell aggregation is a cause of echogenicity in flowing blood. Furthermore, a red cell aggregation mechanism for blood-flow echogenicity would explain the increased prominence of internal echoes in lower shear rate venous blood flow compared with those of higher shear rate arterial blood flow.

Imaging ultrasound in the intraoperative diagnosis of vascular defects.

High-resolution real-time ultrasonography was employed during 267 vascular operations in order to diagnose vascular defects such as intimal flaps, strictures, and thrombi. These defects occur at operative areas (e.g., anastomoses, endarterectomized segments, and sites of placement of occlusive clamps) and can lead to serious thrombotic complications in the early post-operative period. Ultrasound detected vascular defects in 83 patients (31.1 per cent). The defects in 59 patients were considered clinically insignificant because of their sizes and locations, and were not re-explored. Early post-operative results of these patients were comparable to those of the patients without demonstrated defects. In 24 patients (9.0 per cent of all patients examined), ultrasonography revealed clinically significant defects which prompted re-exploration. In 20 of these 24 patients, these vascular defects were confirmed and corrected. No defect was found at re-exploration in four patients, but two of them developed early postoperative thrombosis. Ultrasonography and arteriography were compared at 100 operative sites. The two imaging methods were equal in terms of sensitivity, specificity, efficiency, and predictability of a negative test. Predictability of a positive test was 77.8 per cent for ultrasonography and 59.1 per cent for arteriography. This indicates that fewer needless re-explorations would occur following a decision based on ultrasonography. Operative ultrasonography is a simple, safe and accurate technique that should be applied to reconstructive vascular surgery for diagnosis of vascular defects.

The application of real-time ultrasound imaging during surgical procedures.

Operative ultrasound using real-time high resolution B-mode ultrasound scanning is a practical and useful diagnostic aid. At operations upon the biliary tract, pancreas and blood vessels, ultrasound had a favorable impact upon surgical management. When similar operative roentgenographic studies were available, operative ultrasound compared favorably with both operative cholangiography and arteriography. Problems with the lack of familiarity of the surgeon with the performance and interpretation of imaging ultrasound and lack of specifically dedicated ultrasound instruments need to be resolved to increase and improve the use of this potentially helpful aid to surgical diagnosis during operation.

Imaging ultrasonography during blood vessel operations.

Real-time ultrasound B-mode scanning was used during vascular operations to detect defects produced by reconstructive surgery. Ultrasound detection of defects was more accurate than arteriography. Use of operative imaging led to re-exploration and correction of defects in 8% of patients undergoing vascular reconstruction.

Relation of in vivo blood flow to ultrasound echogenicity.

The mechanism of echogenicity of flowing blood during real-time ultrasonography was investigated experimentally in vivo by scanning venous and arterial blood and venous blood subjected to varying degrees of obstruction. Luminal echoes were more intense in flowing blood of the vena cava than in aortic blood of dogs. Vena cava and portal echoes increased in intensity as flow was decreased progressively by obstruction. We believe that an important cause of echogenicity of flowing blood is red cell aggregation which is greatest at low shear rates (low flow velocity). Echogenicity decreases with increase in shear rate (higher flow velocity) which causes red cell disaggregation.

Ultra-sonografia durante operacoes pancreaticas. / Ultrasonograpy during pancreatic operations

A ultra-sonografia do tipo B-modo "real-time foi utilizada em 64 operacoes pancreaticas, 43 por doenca inflamatoria e 21 por tumor. Em 25 dessas operacoes a ultrasonografia forneceu informacoes adicionais que orientaram no tratamento cirurgico de pseudocistos, abscessos, pancreatites cronicas e tumores pancreaticos.As informacoes consistiam em estabelecer ou excluir o diagnostico de pseudocisto e abscessos pancreatico, localizar pseudocisto e ducto pancreatico principal que nao eram palpaveis, selecionar o melhor local de biopsia pancreatica, avaliar a ressecabilidade do adenocarcinoma de pancreas e localizar tumores pancreaticos endocrinos. A ultra-sonografia per-operatoria e um metodo simples e eficiente para avaliar doenca pancreaticas

Variable ultrasound echogenicity in flowing blood.

Real-time ultrasound imaging of large abdominal veins revealed bloodstream echogenicity of variable intensity. This variability is largely due to the entrance and persistance of tributary blood currents that show different echogenicity. Red cell aggregation is probably an important cause of bloodstream echoes and their variable intensity.