Establishment of a new cell line, OKT1, from small cell carcinoma secreting ectopic ACTH of the uterine cervix

OBJECTIVE

Small cell carcinoma of the uterine cervix is rare and represents a unique entity among gynecological tumors. It sometimes demonstrates neuroendocrine differentiation, including adrenocorticotropin (ACTH) secretion. In this study, we established a new cell line, OKT1, from a case of carcinoma secreting ectopic ACTH without Cushing's syndrome and determined the character of the cell line.

METHODS

OKT1 was established from OKT tumor cells, derived from a biopsy specimen of small cell cervical carcinoma, and serially heterotransplanted into nude mice. To characterize OKT1, the cell morphology, growth properties, immunohistochemical properties, hormone- and tumor-associated antigen secretion, tumorigenic potential, DNA profile, and chromosomal alteration were studied.

RESULTS

The population doubling time of OKT1 was approximately 27 h. The cytological properties of OKT1, including DNA ploidy pattern, were similar to those of the primary tumor. Neuroendocrine differentiation was shown in the OKT1 cells by the positive immunocytochemical staining of neuron-specific enolase (NSE) and the presence of NSE and ACTH in the culture media. The xenograft of 1 x 10(8) OKT1 cells into nude mice yielded tumor mass. Furthermore, OKT1 demonstrated HPV type 18 and absence of a p53 gene mutation from exons 5 through 8.

CONCLUSION

To our knowledge, OKT1 is the first cell line established from small cell cervical carcinoma with ACTH secretion.

Enhanced utilization of phosphonate and phosphite by Klebsiella aerogenes

Klebsiella aerogenes ATCC 9621 was able to utilize phosphonates (Pn), including aminoethylphosphonate, ethylphosphonate, methylphosphonate (MPn), and phosphonoacetate, and inorganic phosphite (Pt) as sole sources of phosphorus (P). The products of the phn gene cluster were absolutely required for Pn breakdown and Pt oxidation to inorganic phosphate (Pi) in this organism. To determine if K. aerogenes ATCC 9621 could be engineered to enhance the utilization of Pn and Pt, a multicopy plasmid, pBI05, which carried the entire phn gene cluster, was introduced into this strain. Despite the increased dosage of the phn genes, K. aerogenes ATCC 9621(pBI05) could utilize only up to 1.1-fold more Pn and Pt than did the control strain with the parent vector alone. These results suggested that Pi, which was generated from Pn and Pt, might limit further utilization of these P compounds. Consequently, to convert the resulting Pi to polyphosphate (polyP), the plasmid pKP28, which carried the K. aerogenes ppk gene (which encodes polyP kinase), was introduced into K. aerogenes ATCC 9621(pBI05). Overexpression of the ppk gene in K. aerogenes ATCC 9621(pBI05, pKP28) resulted in a 2.5-fold increase in Pt utilization over that of the control strain. This recombinant strain also accumulated approximately sixfold more P than did the control strain when the cells were grown with MPn as a sole source of P.

Larynx-preserving resection of the cervical esophagus for cervical esophageal carcinoma limited to the submucosal layer

This report describes the surgical procedure consisting of larynx-preserving resection of the cervical esophagus and satisfactory lymphadenectomy. The sternum was split at the level of the 3rd intercostal space, which allowed an upper-mediastinal lymphadenectomy to be performed easily. The cervical esophagus was reconstructed using a free jejunal autograft. The stump of the thoracic esophagus and the caudad stump of the jejunal graft were anastomosed using a circular stapling instrument. The posterior part of the cephalad esophagojejunostomy was completed in two layers using the Lembert stitch. The wall of the cervical esophagus was opened to determine the oral cut line considering the safety margin from the carcinoma. After cervical esophagectomy was completed, suturing of the anterior wall was performed in one layer. The left cervical transverse artery and the internal jugular vein were employed for recipient vessels. This procedure is acceptable for high cervical esophageal carcinoma limited to the submucosal layer.

Cytotoxicity of absorption enhancers in Caco-2 cell monolayers

This study was performed to evaluate the utility of absorption enhancers with reference to mucosal cell cytotoxicity. Overall assessment of the damage to plasma, lysosomal and nuclear membranes by three absorption enhancers, sodium deoxycholate, sodium caprate and dipotassium glycyrrhizinate, was performed on Caco-2 cell monolayers. The cytotoxicities of sodium deoxycholate (0.02-0.1% w/v), sodium caprate (0.1-0.5% w/v) and dipotassium glycyrrhizinate (0.5-2% w/v) were evaluated by the trypan blue-exclusion test, the protein-release test, the neutral-red assay, the DNA--propidium iodide staining test and the test for recovery of transepithelial electrical resistance (TEER) up to 24 h after treatment with each enhancer. Sodium dodecyl sulphate (SDS; 0.1% w/v), a potent surfactant, was used as positive control. SDS at this level was significantly cytotoxic whereas dipotassium glycyrrhizinate was not cytotoxic in any tests. Results from the trypan blue-exclusion and protein-release tests showed that high concentrations of sodium caprate (0.5% w/v) and sodium deoxycholate (0.1% w/v) were significantly cytotoxic to the plasma membrane. The neutral-red assay, an indicator of damage to lysosomal membranes, revealed that 0.5% (w/v) sodium caprate had no effect whereas the uptake of neutral red was slightly increased by treatment with 0.1% (w/v) sodium deoxycholate, implying that the compound had cell-growth-enhancing activity. Nuclear-membrane damage, as evaluated by the DNA--propidium iodide staining test, was severe in cell monolayers treated with 0.5% (w/v) sodium caprate compared with that induced by 0.1% (w/v) sodium deoxycholate. In the TEER recovery test, TEER failed to recover 24 h after treatment with 0.5% (w/v) sodium caprate and 0.1% (w/v) SDS, but recovered after treatment with 0.1% (w/v) sodium deoxycholate. The recovery of TEER might be related to nuclear membrane damage and cell-growth-enhancing activity. These results indicate that of the three classes of enhancer, dipotassium glycyrrhizinate was not cytotoxic and that high concentrations of sodium caprate and sodium deoxycholate could damage plasma and nuclear membranes.

Prevention of spinal cord ischemia by selective intercostal arterial infusion of prostaglandin E1

PURPOSE

A new protective method against the spinal cord ischemia that occurs during aortic clamping was investigated in dogs. Oxygenated blood containing prostaglandin E1 (PGE1) was administered at the clamped aortic segment, and the effect was evaluated by measurement of the sensory evoked spinal potential (SESP).

METHODS

In 30 dogs, a thoracotomy was made with dissection of the thoracic aorta. After intravenous heparin (100 units/kg) was administered, the proximal and distal descending thoracic aortas were cross-clamped for 60 minutes. Group A (n=10) received oxygenated blood at the rate of 1.0 ml/kg/min. Groups B (n=10) and C (n=10) received oxygenated blood at the same rate, with PGE1 at the dosage of 25 and 50 ng/kg/min, respectively. The infusion was continuously administered throughout the entire period of ischemia. SESP was measured with epidural electrodes before clamping, 10 and 60 minutes after clamping, and 10 and 60 minutes after declamping. Neurologic outcome was assessed at 24 hours after the operation and graded according to the method of Tarlov.

RESULTS

There was no significant hemodynamic change in any group. At 60 minutes after damping and at 10 and 60 minutes after declamping, the amplitude of SESP was lower than that at preclamping in groups A and B (p < 0.05). At 60 minutes after damping and at 10 and 60 minutes after declamping, the SESP was more markedly decreased in group A compared with groups B and C. Regarding postoperative neurologic outcome, the dogs with SESP amplitude of more than 50% of the preclamping control value at 60 minutes after clamping showed neither paralysis nor paraplegia. Seven of nine dogs with less than 50% SESP amplitude showed neurogenic deficit. In a comparison of groups A, B, and C, the Tarlov score for group A dogs was significantly lower than that for group C dogs (p < 0.05).

CONCLUSION

In this model, PGE1 administration at the rate of 50 ng/kg/min showed sufficient spinal cord protection against ischemia without a decrease in the blood pressure. Further studies are needed to determine the dose that will provide the maximal protective effect and to determine the maximum duration of ischemia against which PGE1 shows protective effects.

A solitary iliac artery aneurysm caused by Candida infection. Report of a case

We report a very rare case of an infected aneurysm of solitary common iliac artery by Candida albicans. The patient, a 70 year-old male, had a history of systemic Candidemia infected through intravenous hyperlimentation (i.v.H) catheter 2 years ago. By physical examinations and laboratory data, infectious disease was suspected. Computed tomography showed right hydronephrosis and right solitary common iliac artery aneurysm, and operation was performed with diagnosis of infected aneurysm. The aneurysm was removed with the end of the abdominal aorta, and the arterial blood flow was restored by axillo-bifemoral bypass. Histopathological findings revealed abscess formation around the aneurysm with phlogocytes infiltration in both outer media of aneurysmal wall and vasa vasorum. Candida albicans was found as causative pathogen from resected specimens. This aneurysm is considered to be resulted from surviving candida in vasa vasorum after previous candidemia.

Effects of absorption enhancers on cytoskeletal actin filaments in Caco-2 cell monolayers

Histomorphological changes of actin filaments, intracellular levels of calcium ion, and amount of released lactate dehydrogenase (LDH) were examined, in order to elucidate the mechanism of action of three absorption enhancers, i.e., sodium caprate (Cap-Na), sodium deoxycholate (Deo-Na), and dipotassium glycyrrhizinate (Grz-K), using Caco-2 cell monolayers. The structure of actin filaments in microvilli was slightly modified by 0.5 %(w/v) Grz-K and was significantly changed by 0.2 %(w/v) Cap-Na, 0.05 %(w/v) Deo-Na, and 0.0015 %(w/v) ionomycin. All of the enhancers, except Grz-K, induced significantly histomorphological changes in the actin filaments on the middle depth and basal side of the cells. Furthermore, the altered structure of the actin filaments in the monolayers was restored after removal of the Cap-Na, Grz-K and ionomycin, but not Deo-Na. Intracellular levels of calcium ion increased in the following order: ionomycin = Cap-Na > Deo-Na. However, the intracellular calcium ion levels decreased by treatment with Grz-K. The changes in transepithelial electric resistance (TEER) at the initial stage of treatment with all enhancers correlated with intracellular calcium ion levels. These results suggest that one of the mechanisms by which these agents exert absorption-enhancing activity involves structural alterations in the cytoskeletal actin filaments which are provoked by changes in intracellular calcium ion levels. Only the monolayers which were treated with 0.05 %(w/v) Deo-Na released a significant amount of LDH and irreversibly altered the structure of actin filaments, thus indicating that Deo-Na might affect the actin filaments not only by increasing intracellular calcium ion level but also by other, presently unknown factors.

Development of a genetic transformation system for an alga-lysing bacterium

Four marine bacteria, Alteromonas sp. strains A27, A28, A29, and A30, that lyse the diatom Skeletonema costatum NIES-324 were isolated from coastal seawater samples. They were also able to lyse the diatoms Thalassiosira sp. and Eucampia zodiacs and the raphidophycean flagellate Chattonella antiqua. Cryptic indigenous plasmids, designated pAS28 and pAS29, were detected in Alteromonas sp. strains A28 and A29, respectively. These plasmids appeared to be similar based on size and restriction site analysis. A shuttle vector that replicates in Escherichia coli and Alteromonas sp. strain A28 was constructed by fusing pAS28 and E. coli vector pCRIIc. The 16-kbp chimeric plasmid, designated pASS1, had the ability to transform strain A28 at a frequency of 10(6) transformants per microg of DNA. Deletion analysis of pASS1 showed that the 4.7-kb EcoRI-HindIII region of pAS28 was essential for plasmid maintenance in strain A28. This EcoRI-HindIII fragment contained an open reading frame which appeared to encode a 708-amino-acid protein.

Long-term results of endarterectomy, anatomic bypass and extraanatomic bypass for aortoiliac occlusive disease

Over the past 20 years, 214 patients in our hospital were operated on for aortoiliac occlusion, including an endarterectomy for 88 legs in 64 patients, an anatomic bypass for 178 legs in 105 patients, and an extraanatomic bypass for 51 legs in 45 patients. The extraanatomic group was older than the other two groups (70 years versus 64 years), and also showed a higher instance of critical ischemic symptoms than the other groups (49% versus 16%). The 10-year primary patency rate was 88% for an endarterectomy, 91% for an anatomic bypass, and 73% for an extraanatomic bypass. The 10-year survival rate was 71% for an endarterectomy, 49% for an anatomic bypass, and 24% for an extraanatomic bypass. The possible complications related to each surgical method included sexual dysfunction resulting from endarterectomy, and graft infection and anastomotic aneurysm in the prosthetic bypass. No ischemic symptoms in the donor limb were noted following an extraanatomic bypass. The selection of the appropriate surgical method for aortoiliac occlusion should thus be made after a careful review of the patient's general condition, the morphology of arterial occlusion, and the risk of possible complications for each type of surgery.

The value of detection of flow voids between the uterus and the leiomyoma with MRI

Flow voids are occasionally seen between the uterus and the leiomyoma. This study was performed to determine the prevalence of this sign and its relation to tumor size and location, internal signal intensity of the leiomyomas, and the ease of detectability using different MR sequences. Also, to understand the pathologic causes for the phenomenon of flow voids. The MR images of the pelvis in 92 females with 359 uterine leiomyomas were analyzed. Flow voids located between the uterus and the leiomyomas were seen in 32 lesions on T1-weighted images and in 12 on T2-weighted images. Flow void was seen exclusively in leiomyomas of 3-cm diameter or larger. In five pedunculated subserous leiomyomas, flow voids were seen within the pedicle of the tumor. Large leiomyomas and leiomyomas with irregular signal intensity on T2-weighted images showed significantly greater frequency of signal void than other leiomyomas (P < .01). The sign was not seen in any other pelvic tumors. On pathologic evaluation, the flow voids were found to correspond to dilated feeding arteries located outside the capsule of the leiomyoma.

Acute mesenteric vascular occlusion: analysis of 39 patients

OBJECTIVE

To study the factors that influence mortality and long term outcome of patients with acute mesenteric vascular occlusion.

DESIGN

Retrospective study.

SETTING

University hospital, Kanazawa, Japan.

PATIENTS

Thirty-nine patients treated between 1978 and 1995 for acute mesenteric vascular occlusion.

INTERVENTIONS

34 patients underwent laparotomy. Bowel was resected in 29 patients, and primary anastomosis was done in 20. The occluded vessel was revascularised in 5 patients.

MAIN OUTCOME MEASURES

mortality, short bowel syndrome and long term survival.

RESULTS

25 patients had arterial occlusions, and 8 venous. In the remaining 6, the occluded vessel was not identified. 11 Patients developed renal failure, 11 respiratory failure, and 10 disseminated intravascular coagulation (DIC). Twelve patients died within 30 days. The factors associated with early death were acidosis and high serum amylase activity. 9 Patients developed the short bowel syndrome. Survival was 49% at 1 year, and 34% at 5 years.

CONCLUSION

Mortality was higher in patients with advanced peritonitis. Mesenteric revascularisation should be attempted to avoid the short bowel syndrome.

Surgical drainage for idiopathic suppurative pylephlebitis

Idiopathic suppurative pylephlebitis is quite rare and only a few cases have been reported. Conservative systemic administration of antibiotics and urokinase is reported to be effective. In this report, surgical drainage was performed on an 18-year-old man who complained of fever and abdominal pain. He had no past history of abdominal inflammatory disease or abdominal surgery. Ultrasonography and computed tomography showed wide spread thrombosis of the portal vein. Laparotomy was performed and the occluded superior mesenteric vein was incised. Massive pus was removed. Thereafter, a drain was placed at the opened mesenteric vein. Drainage resulted in a dramatic decrease in fever. Postoperative radiographic studies of the colon, the small intestine, and other organs did not show any abnormalities. Emergency surgical drainage was performed successfully, instead of systemic administration of antibiotics and urokinase. Surgical drainage may be useful for wide spread pylephlebitis and pylethrombosis.

Comparison of cilostazol with warfarin as antithrombotic therapy after femoro-popliteal bypass surgery using an ePTFE graft

BACKGROUND

Cilostazol (6-[4-(1-cyclohexyl-1H-tetrazol-5-yl)butoxy]-3,4- dihydro-2(1H)-quinolinone) is a new antiplatelet agent with a vasodilating action. The purpose of this study was comparison of cilostazol with warfarin as antithrombotic therapy after femoro-popliteal bypass surgery using an expanded polytetrafluorethylene (ePTFE) graft.

EXPERIMENTAL DESIGN

This report is a retrospective study and the patients were followed up for five years.

SETTING

Outpatients of university hospital.

METHODS

Sixteen arteriosclerosis obliterans patients, who were diagnosed as having only superficial femoral artery stenosis or occlusion, underwent femoro-popliteal (above the knee) bypass using an ePTFE graft 6 mm in diameter. Cilostazol (150-200 mg/day) was administered to 6 cases (9 bypasses), and warfarin (prothrombin time was controlled to 15-25%.) was administered to 10 cases (14 bypasses).

RESULTS

No clinically characteristic differences were found between the two groups. The cumulative 1-, 3-, and 5-year primary and secondary graft patency rates were 69% and 80%, 69% and 80%, and, 69% and 80% in the cilostazol group, vs 61% and 91%, 51% and 91%, and, 51% and 91% in the warfarin group, respectively. These differences were not significant (p < 0.05). No hemorrhage complications were observed in the cilostazol group. The management of cilostazol administration was safe and simple.

CONCLUSIONS

Although the number of cases was small in this study, cilostazol was considered to be as effective as warfarin and suitable for the postoperative antithrombotic therapy after the ePTFE bypass surgery.

Exclusion of a sciatic artery aneurysm and an obturator bypass

This case report describes surgical treatment in a sciatic artery aneurysm with hypoplastic external iliac and femoral arteries. An obturator bypass grafting procedure from the internal iliac artery to the distal sciatic artery was performed after aneurysmal exclusion was achieved by proximal and distal ligation. This method offers an acceptable option for surgery in some types of sciatic artery aneurysms.

Isolation and characterization of Enterobacter cloacae mutants which are defective in chemotaxis toward inorganic phosphate

Enterobacter cloacae IFO3320 is attracted to Pi when cells are starved for Pi. Two Tn1737KH-induced mutants, which were constitutive for alkaline phosphatase, failed to exhibit Pi taxis even under conditions of Pi limitation. Both of the mutant strains exhibited normal chemotactic responses to peptone, suggesting that they are specifically defective in Pi taxis. Cloning and sequence analysis showed that the TN1737KH insertions were located in either the pstA or pstB genes which encode the channel-forming proteins of the Pi-specific transport (Pst) system in E. cloacae. These results suggest that the E. cloacae Pst system is required for Pi chemoreception.

Bypass grafting for a right proximal subclavian artery pseudoaneurysm patient using a long temporary bypass

We report an 80-year-old woman, with pseudoaneurysm of the right proximal subclavian artery despite the absence of a history of trauma. On preoperative examinations, the aneurysm involved to the common carotid arteries. A long temporary bypass using a heparin-coated tube from the right femoral artery to the right common carotid artery was created under low dose systemic heparinization. A Dacron bifurcation graft bypassing was then performed successfully. At surgery for right proximal subclavian artery aneurysm, which often involves the right common carotid artery, intraoperative accident or bleeding can induce brain ischemia. A temporary bypass should be prepared. Although the short temporary bypass from the aorta to the right common carotid artery was reported, this carries the risk of complications due to microemboli. The heparin-coated tube provided excellent anti-thrombosis. Inflow cannulation should be placed at the peripheral artery not the aorta.

Ultraviolet short pulses from an all-solid-state Ce:LiCAF master-oscillator power-amplifier system

We have developed an all-solid-state master-oscillator-power-amplifier system employing Ce:LiCAF, a new degradation-free tunable ultraviolet laser medium pumped by the fourth harmonic of conventional 10-ns Q -switched Nd:YAG lasers. The low- Q , short-cavity Ce:LiCAF master oscillator produced a satellite-free 1-ns pulse under appropriate pumping-fluence control. 18% energy extraction with sufficient gain was achieved in a single-stage, confocal, double-pass amplifier. As a result, 289-nm, 1-ns, 14-mJ pulses were efficiently obtained from this simple laser system.

Effects of absorption enhancers on the transport of model compounds in Caco-2 cell monolayers: assessment by confocal laser scanning microscopy

Three typical absorption enhancers, i.e., sodium caprate (Cap-Na), sodium deoxycholate (Deo-Na), and dipotassium glycyrrhizinate (Grz-K), were compared in terms of their permeability-enhancing effects on hydrophilic and hydrophobic model compounds in Caco-2 cell monolayers. The transepithelial electrical resistance (TEER) of the monolayers was reduced concentration-dependently by treatment with Cap-Na and Deo-Na, while treatment with Grz-K increased the TEER. Two patterns of TEER reduction were observed: one pattern indicated that Cap-Na had a rapid reducing effect, and another indicated that Deo-Na had a delayed reducing effect. These reductions in the TEER were accompanied by the increased transepithelial transport of two hydrophilic model compounds, sodium fluorescein (Flu-Na; MW = 376, log P = -1.52) and fluorescein isothiocyanate-dextran 4000 (FD-4; MW = 4400, log P = -2.0), and one hydrophobic model compound, rhodamine 123 hydrate (Rh123; MW = 381, log P = 1.13). The transport-enhancing effects of Cap-Na and Deo-Na on these model compounds decreased in the following order: FD-4 > Rh123 > Flu-Na, while Grz-K was found to have no effect on the transport of any of these model compounds. Confocal laser scanning microscopy (CLSM) of Caco-2 cell monolayers revealed that Cap-Na and Deo-Na enhanced the transepithelial transport of the hydrophilic model compounds via the paracellular route and that of the hydrophobic model compound via both paracellular and transcellular routes. Semiquantitative visual information obtained from CLSM images reflected the results of the transport experiment.

Pharyngoesophageal reconstruction with the use of vascular anastomoses: operative modifications and long-term prognosis

OBJECTIVE

Vascular surgical techniques have contributed to the success of pharyngoesophageal reconstruction. We report our methods and analysis of postoperative complications, quality of life, and long-term prognosis.

METHODS

Sixty-seven patients who underwent pharyngoesophageal reconstruction with use of vascular anastomoses comprised the study population. The operative procedures performed were free jejunal autograft transplantation in 54 patients, gastric pedicle placement with vascular anastomoses in 2, jejunal pedicle with vascular anastomoses in 4, colonic pedicle with vascular anastomoses in 4, free jejunal graft and gastric pedicle in 2, and free jejunal graft and jejunal pedicle in 1. The common carotid artery and internal jugular vein were primarily used as the recipient vessels. The period of postoperative observation ranged from 3 days to 145 months.

RESULTS

The postoperative complications noted were dehiscence in 7 patients, graft failure in 1, wound infection in 2, small bowel intussusception in 4, pneumonia in 2, disseminated intravascular coagulation in 1, and pancytopenia in 1. Revascularization was successful in all but 1 patient, and oral intake was achieved in 58. Persistent swallowing dysfunction was recognized in 4%. Speech restoration was achieved in 57% of the patients with esophageal speech in 7% and with an artificial larynx in 50%. In the long-term follow-up, 36% of our patients died of the primary disease, 9% died of other diseases, and 55% are alive.

CONCLUSIONS

Esophageal reconstruction with the use of vascular anastomoses affords low morbidity and mortality. Postoperative swallowing and speech are satisfactory, and the function of the reconstructed esophagus is well preserved for as long as 10 years.

Postoperative influences of surgical cryoablation for Wolff-Parkinson-White syndrome--a analysis of myocardial enzymes and function

We evaluated postoperative myocardial enzymes and function associated with cryoablation in 20 patients with Wolff-Parkinson-White syndrome undergoing surgical treatment for a single left-sided accessory conduction pathway. Ten patients underwent endocardial atrial incision with cryoablation using CO2 at -60 degrees C for 120 sec (group A), while the remaining 10 patients did not receive cryoablation (group B). Levels of aspartate aminotransferase (GOT), lactate dehydrogenase (LDH), and creatine kinase (CK-MB) on postoperative days 1, 2, and 3 were higher in patients in group A than in group B (p < 0.05). However, mean values remained low (GOT, 120.5 IU/L; LDH, 1105.1 IU/L; CK-MB, 76.3 IU/L). No electrocardiographic changes were detected. Parameters of cardiac function, including cardiac index, stroke volume index, systemic vascular resistance, and ejection fraction, remained unchanged during the postoperative period in both groups. Furthermore, 201Tl cardiac scintigraphy demonstrated no evidence of myocardial perfusion defects due to cryoablation in group A. In conclusion, myocardial damage induced by cryoablation is very minor and is not associated with any clinical impairment of cardiac function.

Long-term results of flow reversal and thromboexclusion method for thoracic aortic aneurysm

BACKGROUND

The long-term results of flow reversal and thromboexclusion for the elimination of a thoracic aortic aneurysm were studied.

METHODS

We monitored the posttreatment course in 10 patients with a thoracic aortic aneurysm who underwent thromboexclusion between 1981 and 1990. All patients had comorbid factors, such as renal failure, myocardial infarction, or respiratory dysfunction, and the entire descending thoracic aorta was involved in all. One patient with impending rupture underwent permanent occlusion of both the proximal and distal aortas, and the remaining 9 patients underwent proximal aortic occlusion only.

RESULTS

Two patients died within 30 days of operation. Postoperative cerebral infarction occurred in 1 patient, possibly as the result of the release of atheroma emboli at the time of permanent clamping. Incomplete paraplegia occurred in 1 patient 15 months postoperatively. Two patients died as the result of comorbid conditions 3 and 39 months after operation; 1 patient died as the result of penetration of the lung by the permanent clamp 12 months after operation. An aortic aneurysm recurred in 4 patients, and 3 of them died of aneurysmal rupture 50,55, and 63 months after operation, respectively. The fourth patient with aneurysmal recurrence underwent reoperation and is alive 124 months postoperatively. Another patient is alive without recurrence 140 months postoperatively.

CONCLUSIONS

Because of the postoperative complications and the risk of aneurysm recurrence, the thromboexclusion method should be used only in patients with an infected aneurysm or in those with a severely morbid condition.

Physiological changes during acute obstruction of the superior vena cava, azygos, and internal thoracic veins in dogs

PURPOSE

In the surgery for superior vena cava (SVC) reconstruction, the cross-clamping of the SVC may cause brain damage. Experimental study was performed to clarify the safe limit of the clamping time and the appropriate monitoring method during the surgery.

METHODS

In anesthetized dogs, the internal thoracic and azygos veins were ligated, and the SVC was clamped for 120 min. Arterial blood pressure, intracranial venous pressure, regional cerebral blood flow, and electroencephalogram were monitored in six dogs. Somatosensory evoked potentials were recorded in one other dog, and in another dog postoperative neurological changes were evaluated for 3 weeks. The brains of the dogs were subjected to the histological examination including tetrazolium stain.

RESULTS

The arterial blood pressure decreased and the intracranial venous pressure increased during the clamping. Oscillation of the pressure was noted at 45 to 74 min after clamping. The regional cerebral blood flow was 57.4 ml/100 g/min on average before clamping, and decreased to 15.5 ml/100 g/min at 105 min after clamping. The electroencephalogram demonstrated no pronounced change during clamping, but the amplitude of the somatosensory evoked potentials decreased and the latency was prolonged during clamping. No neurological defect was noted in the dog observed for 3 weeks. All areas of the brain showed staining with the tetrazolium, indicating intact mitochondria. The microscopic findings for the brains included no marked changes.

CONCLUSION

The SVC clamping for 120 min was tolerated by the dogs, and the most reliable monitoring method was concluded to be the recording of somatosensory evoked potentials.

Hot-knife dissection of the latissimus dorsi muscle for dynamic cardiomyoplasty

The overall purpose of circulatory assistance utilizing skeletal muscle is the most efficient application of muscle power. From the histological viewpoint, hot-knife dissection of the latissimus dorsi muscle (LDM) is presented to preserve muscle tissue. The shaw hemostatic scalpel could be used similarly to standard surgical blades, and its hemostatic performance was efficient in sealing collateral vessels from the thoracic wall. Muscular and nervous twitching was never observed throughout dissecting the LDM. Histological findings revealed that muscle fibers could be preserved by hot-knife dissection rather than by electrocautery. This technique may reduce the inconvenience of the operators, and, therefore, shorten the operation time in dynamic cardiomyoplasty and other experiments.