Delayed thromboembolectomy for subacute limb ischemia.

Arterial embolization frequently requires immediate operative intervention. Occasionally, embolic events produce subacute limb ischemia that may not be recognized as thromboembolic in origin. In October 1988, a prospective policy to attempt thromboembolectomy rather than infrainguinal bypass in all patients with delayed presentation of lower limb thromboembolism was initiated at our institution. Seven limbs in five patients were identified by history, physical examination, noninvasive study, and/or angiography as ischemic due to thromboembolism, which occurred from 3 to 10 weeks prior to presentation. Six of seven limbs were studied angiographically, and all seven were treated by femoral and/or popliteal thromboembolectomy with limb salvage. Six of seven limbs were restored to normal arterial hemodynamics as assessed by intra- and postoperative noninvasive study. One limb in a patient continued to have minimal residual occlusive disease that was recognized preoperatively. In all cases, chronic and fresh thromboemboli were found at surgery and confirmed by pathology. Chronic thromboembolism seems to be an underrecognized event. Limb salvage can be achieved readily even if extensive delay in diagnosis is present. Using preoperative angiography and intraoperative noninvasive techniques to measure the success of revascularization, as well as avoiding, when possible, complex infrainguinal reconstruction in these high-risk patients allows for an aggressive approach to limb salvage with gratifying results.

Predictors of outcome in early revascularization after acute myocardial infarction.

We have reviewed 44 consecutive patients undergoing myocardial revascularization from 1 to 42 days after myocardial infarction. Operation within 12 days of transmural myocardial infarction carried a substantially high risk, particularly in patients with poor ventricular function. Patients with subendocardial infarction may be safely operated on shortly after infarction has occurred. In those with transmural infarcts, it may be advantageous to delay operation if early and aggressive medical therapy can effectively control the symptoms. This has to be counterbalanced, however, by the realization that the situation should not be allowed to slide into one of irreparable ventricular damage from infarct extension.

Early ileostomy closure in necrotizing enterocolitis.

The nutritional and metabolic complications following intestinal resection and ileostomy for necrotizing enterocolitis (NEC) in low birth weight preterm infants often necessitate repeated prolonged hospitalization for salt and water imbalance and reliance on total parentaral nutrition (TPN). The traditional concerns about anesthetic and anastomotic complications delays the restoration of intestinal continuity until the infant has attained a weight of about 5 kg, but recent nutritional balance studies in our unit have shown a combination of nutrient and mineral malabsorption in neonates with ileostomies. Beginning 4 years ago, a prospective study of early closure of the ileostomy was undertaken in infants weighing as low as 2 kg to examine the effect on surgical morbidity, infant growth, and gastrointestinal function using the preclosure infant as his/her own control. Ten infants with birthweights ranging from 670 to 2,000 g developed NEC requiring ileostomy at age three days to 11 weeks. In addition to partial ileal resection, the cecum was resected in 10 patients, ascending colin in 7, transverse in 4, descending colon in 1 patient. Postoperative treatment, including short-term TPN and elemental diet, preceded closure of ileostomy at a mean age of 18 weeks (range 5 to 36 weeks). Mean weight at time of closure was 3,052 +/- 994 g. There were no short-term complications of early closure in this series, nor was there any incidence of anastomotic dysfunction, colon stricture, or recurrent NEC.(ABSTRACT TRUNCATED AT 250 WORDS)

Decompression of the occluded subclavian vein in the patient with ipsilateral threatened access by transposition of the internal jugular vein.

Thrombosis or stenosis of the subclavian vein is frequently caused by cannulation for dialysis or nutritional access. In a patient with an ipsilateral arteriovenous fistula, the resulting edema and venous congestion can interfere greatly with dialysis and can lead to limb threatening significant disability to the point of phlegmasia cerulea dolens. The author describes four patients who underwent a recently described procedure to decompress the venous system in the setting of subclavian obstruction. A description of the technique is included.

Current status of carotid endarterectomy.

Extracranial cerebrovascular disease (ECVD) is a major contributor to cerebrovascular accidents in the modern era. Cerebrovascular accidents (CVAs) are the third leading cause of death in the United States with 500,000 new or recurrent CVAs each year. Approximately 15,000 people die annually as a direct result of a stroke resulting in a cost of approximately $18 billion when hospital charges and loss of productivity figures are tabulated. The social and economic impact of this disease mandates a unified approach to its management.

Quality assessment and vascular disease: the analytic imperatives confronting vascular surgeons in the new era.

Vascular Surgery is poised at the edge of a rare moment in medical care. Energy, intelligence, innovation, and resources are available to improve greatly the methods of vascular disease correction. Precedent exists for the overzealous application of technologies. Poor study design and inadequate tracking of outcomes can dilute the value, discredit a critical therapy, and undermine proper patient selection. The proper analysis of our new technologies will be obtained only through well-organized studies, information systems, and informed organizational oversight. Our analysis must extend beyond procedure-specific outcomes to include quality of life issues measured in a validated and relevant fashion. The present and future of vascular disease therapeutics must reside under the control of those who have devoted their lives to its theory and practice.

Thoracoabdominal repair of a post-traumatic aortorenal vein fistula following a previous transabdominal attempt: case report.

Aortorenal vein fistula from trauma is a rare entity. A case is reported in which previous anterior abdominal attempts at repair rendered a thoracoabdominal approach necessary. Previous reports and techniques are compared and discussed.

Prothrombotic and fibrinolytic function of normal and perturbed endothelium.

Endothelium mediates thrombosis and fibrinolysis in part through cell-based production and binding of coagulation factors and anticoagulant moieties. A variety of biologically active agents (homocysteine, interleukin-1, and endotoxin) and environmental factors (mechanical injury and hypoxia) can upset the homeostasis of the coagulation system leading in vitro and in vivo to abnormal propensity for thrombin formation. None of the above agents or any similar agents have been demonstrated to inhibit clotting factors or thrombosis formation. As one would expect, injury to endothelium even on a sublethal basis promotes a procoagulant response. This procoagulant response appears to be multifactorial and multiphasic. Gross injury leads to factor release by dead or dying cells with rapid promotion of thrombosis by neighboring infact cells. A more subtle prothrombotic state promulgated by viable cells appears after sublethal perturbation and is characterized by protein synthesis-dependent production of endothelial-produced clotting factors in the early stages of injury with subsequent return to normal levels of these factors by 24 hr. A second phase of abnormal levels of fibrinolysis inhibitors and possible reduction in fibrinolysis promoters appears to follow up to 48 hr after the initial injury. Thus the cell can be viewed as producing means of promoting thrombus formation followed by preventing thrombus dissolution. The data presented in this article are primarily cell culture data and are thus limited both in physiologic applicability and in ability to define over long periods the relevance of those findings to other cells in the hemostatic system. Nonetheless, in vivo data of endothelial perturbation correlate with the in vitro findings.(ABSTRACT TRUNCATED AT 250 WORDS)

Endothelin production by hypoxic human endothelium.

PURPOSE: The physiologic significance of endothelin remains incompletely defined. Procoagulant and antifibrinolytic activities are increased in hypoxic cultured human umbilical venous endothelial cells (HUVEC). We examined the effect of hypoxia on HUVEC endothelin-1 production in vitro to determine whether a correlation existed between the procoagulant and antifibrinolytic response to hypoxia previously observed and an increase in vasoconstrictor peptide secretion by hypoxic HUVEC. METHODS: Cultured HUVEC were rendered hypoxic (PO2 = 40 mm Hg) or control (PO2 = 120 mm Hg) for 24 hours. Media were either standard, 5 gm glucose/L (high glucose), or contained 500 units superoxide dismutase/ml (SOD). Endothelin-like immunoreactivity for endothelin-1 (ET-IR) in conditioned media was measured by radioimmunoassay and expressed as mean femtomoles per milliliter (+/- SD) per 100,000 cells. Viability of HUVEC was assessed by trypan blue exclusion. Significance was determined by use of Student's t test. RESULTS: Conditioned media from hypoxic cells contained 76% more ET-IR than was found in control counterparts (p < 0.004). The addition of high glucose or SOD did not diminish ET-IR; a trend to higher ET-IR was present in both these groups versus standard media (303% and 226%, respectively, p < 0.03). CONCLUSIONS: Thus 24 hours of hypoxia caused an increase in conditioned-media ET-IR in cultured HUVEC. Because SOD or greater substrate availability did not diminish endothelin presence in conditioned media, it seems that hypoxic induction of endothelin-1 production or secretion is signaled in a fashion unrelated to cell toxicity from the hypoxic period.

Internal jugular to axillary vein bypass for subclavian vein thrombosis in the setting of brachial arteriovenous fistula.

Placement of central venous catheter is the most common cause of subclavian vein thrombosis. In the setting of a functioning ipsilateral brachial arteriovenous fistula, venous hypertension symptoms may be exacerbated. We report successful decompression of severe venous hypertension in the right arm of a patient whose only access for hemodialysis was a functioning right brachial arteriovenous fistula and in whom proximal subclavian vein occlusion developed from a previous percutaneous dialysis catheter. Transposition of the right internal jugular vein and end-to-side anastomosis to the right axillary vein provided prompt and effective venous outflow, with complete resolution of venous engorgement of the affected limb and preservation of the dialysis fistula.

The role of external carotid endarterectomy in the treatment of ipsilateral internal carotid occlusion: collective review.

Complete occlusion of the internal carotid artery (ICA) may result in a variety of clinical states. Neurologic symptoms in the setting of ICA occlusion may be due to embolic events through the external carotid artery (ECA) circulation, hemodynamic insufficiency resulting from inadequate collateral development, or propagation of clot intracranially. External carotid reconstruction has been used to prevent neurologic events from the first two mechanisms. This review attempts to place in perspective the current indications for, techniques of, and results from ECA revascularization. A discussion of the cerebral collateral circulation is included for reference. Twenty-three series were collected from the literature. Cases were excluded in which procedures other than ECA reconstruction were undertaken, leaving 218 cases for analysis. These represented 195 EC endarterectomies and 23 ECA bypasses. Resolution of symptoms was seen in 83% of patients with another 7% showing marked improvement. The perioperative mortality rate was 3%; neurologic deaths accounted for most perioperative deaths. The overall neurologic complication rate was 5%. More recent reports were notable for improved mortality and morbidity. A diseased contralateral carotid artery was associated with higher neurologic morbidity whereas disease in the vertebral arteries had no impact on outcome. The best results were obtained when surgery was performed to relieve specific hemispheric or retinal symptoms as opposed to nonspecific neurologic complaints or previous stroke. The symptomatic patient with ICA occlusion has a poor neurologic prognosis. In selected circumstances ECA reconstruction should be considered among the treatment options in this clinical setting.

Choledochal cysts in the adult.

Although choledochal cyst is generally considered a disorder of childhood, in approximately 20% of patients a cyst is first recognized in adult life. We reviewed nine adults who underwent operation for choledochal cyst from 1974-1985 at Yale New Haven Hospital. Presenting symptoms included: crampy right upper quadrant pain, jaundice, pruritus, cholangitis, pancreatitis, hepatomegaly, and elevated liver function tests. Seven patients had undergone previous biliary surgery. The eight patients with type I cysts underwent complete excision of the cysts with Roux-Y choledochojejunostomy. One patient with a type IVa cyst underwent Roux-Y cystjejunostomy. All patients had complete resolution of biliary symptoms. There were no deaths, serious complications, or development of biliary malignancy in the 6 months to 13 years of follow-up. Optimum treatment of choledochal cyst is complete excision with reconstruction by Roux-Y choledochojejunostomy.

Esophageal rupture after routine Maloney dilatation. A proposed mechanism.

Maloney dilatation of the esophagus is rarely associated with esophageal rupture. An 82-year-old man underwent routine upper endoscopy followed by esophageal dilatation, which was complicated by severe esophageal disruption and mediastinitis. One possible mechanism is gastric dilatation with obturation of the distal esophagus causing excessive pressure at the gastroesophageal (GE) junction. Endoscopy should always be followed by gastric air removal before introducing esophageal dilators.

The effects of external compression on venous blood flow and tissue deformation in the lower leg.

External pneumatic compression of the lower legs is effective as prophylaxis against deep vein thrombosis. In a typical application, inflatable cuffs are wrapped around the patient's legs and periodically inflated to prevent stasis, accelerate venous blood flow, and enhance fibrinolysis. The purpose of this study was to examine the stress distribution within the tissues, and the corresponding venous blood flow and intravascular shear stress with different external compression modalities. A two-dimensional finite element analysis (FEA) was used to determine venous collapse as a function of internal (venous) pressure and the magnitude and spatial distribution of external (surface) pressure. Using the one-dimensional equations governing flow in a collapsible tube and the relations for venous collapse from the FEA, blood flow resulting from external compression was simulated. Tests were conducted to compare circumferentially symmetric (C) and asymmetric (A) compression and to examine distributions of pressure along the limb. Results show that A compression produces greater vessel collapse and generates larger blood flow velocities and shear stresses than C compression. The differences between axially uniform and graded-sequential compression are less marked than previously found, with uniform compression providing slightly greater peak flow velocities and shear stresses. The major advantage of graded-sequential compression is found at midcalf. Strains at the lumenal border are approximately 20 percent at an external pressure of 50 mmHg (6650 Pa) with all compression modalities.

Crack-related perforated gastropyloric ulcer.

Cocaine is a potent topical vasoconstrictor that causes nasal mucosal and dermal ulceration. Use of the purified cocaine derivative "crack" has reached epidemic proportions in large cities. In 18 months we operated on 24 patients with perforated peptic ulcers. Five of the patients were young (27-38 years) male crack users without prior history of gastric symptoms who presented with a perforated gastric ulcer related to smoking crack. Three had had symptoms for only 1-5 days before admission. All five were afebrile, had a rigid abdomen, normal leukocyte count, and free intraabdominal air upon radiography. Five other age-matched, non-crack-using patients served as case controls. Their duration of symptoms was 1-24 months, they had elevated leukocyte counts on admission, and, in contrast to the crack users, four of these patients had duodenal perforations. The clinical presentation of the crack smokers and the unusual localization of the perforations imply different pathogenetic mechanisms than are commonly seen in perforated ulcer disease. With increasing abuse of crack, greater numbers of patients with this new complication may be expected to present to emergency services in urban areas.

Hypoxia induces procoagulant activity in cultured human venous endothelium.

Although it normally presents a nonthrombogenic surface, endothelium is capable of procoagulant activity and suppression of native anticoagulant properties. We theorized that hypoxia could shift normal endothelium into a procoagulant state and tested this hypothesis in cultured human umbilical venous endothelial cells. Human umbilical venous endothelial cells were obtained from fresh umbilical cords. Passage two cells were placed in control (PO2 greater than 120 mm Hg) or hypoxic (PO2 less than 60 mm Hg) media and incubated in control or hypoxic environments for 24 hours. In additional experiments, cells were reoxygenated for 4 or 48 hours after the initial hypoxic period. Cells were then assayed for procoagulant activity expressed as thromboplastin unit equivalents per 100,000 cells based on a thromboplastin standard curve. Results are expressed as percent increase in thromboplastin unit equivalents/100,000 cells +/- standard error versus control. Statistical significance was assessed by paired t test with p less than 0.05 considered significant. More than 95% of cells in all experimental and control preparations were viable after completion of the protocols. No morphologic variation was noted among the control and hypoxic groups. For cells rendered hypoxic without reoxygenation, the mean increase in procoagulant activity for the group (n = 4) versus control was 77% +/- 13% (p = 0.01). In the hypoxia and 4-hour reoxygenation group (n = 4), the mean increase in procoagulant activity was 141% +/- 43% (p less than 0.05). In cells reoxygenated for 48 hours after hypoxia (n = 8), the mean increase in procoagulant activity was 198% +/- 34% (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Mesenteric shunting decreases visceral ischemia during thoracoabdominal aneurysm repair.

PURPOSE: A technique to decrease visceral ischemic time during thoracoabdominal aneurysm (TAA) repair is reported. METHODS: A 10 mm Dacron side-arm graft is attached to the aortic prosthesis and positioned immediately distal to the planned proximal thoracic aortic anastomosis. On completion of the anastomosis, a 16 to 22 Fr perfusion catheter is attached to the side-arm graft and inserted into the orifice of the celiac axis or superior mesenteric artery. The cross-clamp is then placed on the aortic graft distal to the mesenteric side-arm graft. Pulsatile arterial perfusion is thus established to the visceral circulation while intercostal anastomoses or reconstruction of celiac, superior mesenteric, and right renal arteries is performed. Visceral ischemic time and the rise in end-tidal Pco2 after reconstruction of the visceral vessels in patients with mesenteric shunting was compared with a control group matched for aneurysm extent and treated immediately before use of the mesenteric shunt technique. RESULTS: Between July and Oct, 1996, the technique was applied in 15 patients undergoing type I, II, or III TAA repair with a clamp and sew technique. The mean decrease in systolic arterial pressure was 12.5 +/- 8.5 mm Hg, with a concomitant rise in end-tidal Pco2 (mean, 6.9 +/- 5.8 mm Hg), after perfusion was established through the mesenteric shunt. Mean time to establishment of visceral perfusion through the shunt was 25.5 +/- 4.4 minutes; the resultant decrement in visceral ischemic time averaged 31.3 minutes (i.e., until celiac, superior mesenteric, and right renal arteries were reconstructed). Compared with controls, patients with shunts had a significantly decreased (6.9 +/- 5.8 versus 21.6 +/- 8.4 mm Hg; p = 0.0003) rise in end-tidal CO2 on completion of visceral vessel reconstruction. CONCLUSIONS: In-line mesenteric shunting is a simple method to decrease visceral ischemia during TAA repair, and it is adaptable to clamp and sew or partial bypass and distal perfusion operative techniques.

The esophageal obturator airway: obturator or obtundator?

The esophageal obturator airway (EOA) has been approved for use in cardiopulmonary resuscitation (CPR) since 1973. Complications reported with its use include esophageal rupture, aspiration, and inadvertent tracheal occlusion or intubation with the obturator. Five cases of unrecognized tracheal intubation occurring in 170 cases of EOA use during CPR are reported. Records were analyzed for extent and treatment of injuries in the field and the hospital, blood gas levels before and after replacement of the erroneously placed EOA with an endotracheal tube (ETT), and outcome. Blood gas analysis confirmed absent ventilation and profound acidosis following tracheal intubation with the EOA with average EOA arterial blood gases: pH 6.9/pCO2 78/pO2 47. Mortality from this complication was 100%. Tracheal intubation with the EOA is under-recognized and under-reported. It is a potentially lethal complication. The EOA should be replaced with standard bag mask technique or preferably endotracheal intubation in the field by emergency medical technicians.

Substrate specificities of base-level and induced forms of oncofetal alkaline phosphatase in HeLa cells.

HeLa65 cells contain an oncofetal form of alkaline phosphatase that exhibits an increase in catalytic activity when cultures are grown in medium containing adrenal glucocorticoid hormones such as hydrocortisone or its analogue prednisolone. The increase in alkaline phosphatase specific activity in cells grown with hormone is apparently the result of a reduced phosphate content of the enzyme which alters the transition state of the enzyme-substrate complex with an increase in catlytic efficiency. Fourteen different substrates possessing aliphatic, aromatic and heterocyclic configurations were studied with respect to the initial velocities of hydrolysis catalyzed by the base-level and induced forms of the enzyme. The magnitude of increase in catalytic activity was not substantially influenced by the structure of the nonphosphoryl moiety of substrates.

Blunt innominate injury: a report of three cases.

Three consecutive successful repairs of innominate artery tears caused by blunt trauma are reported. Attention is called to the fact that the innominate artery is the second most common site of great vessel injury in this setting. The liberal use of standard angiography and subtraction techniques after high kinetic energy blunt trauma is encouraged. Once the injury is diagnosed, expeditious repair must be undertaken using the principles of adequate exposure for proximal and distal control and careful assessment of cerebral collateral blood flow. Median sternotomy, with a cervical extension if necessary, is the incision of choice. Successful repair is the usual outcome.