[Hemorrhagic Colon Cancer with Left Atrial Thrombus Formation after Anticoagulant Therapy Discontinuation-A Case Report]

The patient was a 72-year-old female. She had been taking rivaroxaban for chronic atrial fibrillation; however, she stopped taking it due to anemia and was hospitalized urgently. A contrast-enhanced computed tomography(CT)scan showed a 30 mm mass in the ascending colon, and a colonoscopy revealed ascending colon cancer(cT3, cN0, cM0, cStage Ⅱa). The tumor was hemorrhagic and was thought to have caused the anemia. On day 6 of hospitalization, another contrast- enhanced CT scan showed a poorly contrast-enhanced area in the left atrium, and transesophageal echocardiography revealed 2 left atrial thrombi(27 mm and 17 mm). Since early induction of anticoagulation therapy was considered, an emergency open right colectomy was performed to remove the cause of the bleeding. Intravenous heparin therapy was started the day after surgery and was switched to oral apixaban therapy on the fourth postoperative day. The postoperative course was good, and she was discharged home on the 17th postoperative day. This patient had conflicting clinical problems simultaneously; however, immediate decision-making and initiation of treatment were effective.

Successful omental flap coverage repair of a rectovaginal fistula after low anterior resection: a case report

BACKGROUND

Rectovaginal fistula (RVF) is a troublesome and refractory complication after low anterior resection (LAR) for rectal cancer. An omental flap repair was performed for the RVF caused due to Crohn's disease and childbirth trauma. However, there are few cases of an omental flap repair for RVF after LAR. Herein, we present a successfully repaired case of RVF by omental flap coverage after LAR for rectal cancer.

CASE PRESENTATION

A 50-year-old female patient with advanced rectal cancer underwent laparoscopic LAR with double-stapling technique anastomosis and achieved curative resection. She complained of a stool from the vagina and was diagnosed with RVF on the postoperative day (POD) 18. Conservative therapy was ineffective. We performed laparoscopic fistula resection and direct closure of the vagina and rectum, designed the omentum that could reach the pelvis, repaired RVF by omental flap coverage, and performed transverse colostomy on POD 25. She was discharged on initial POD 48. Seven months after the initial operation, colostomy closure was administered. There was no recurrence of RVF found 1 year after the initial operation.

CONCLUSIONS

The patient achieved an omental flap coverage for RVF. We successfully performed the omental flap coverage repair in patients with RVF after the leakage of LAR. An omental flap may become an alternative treatment for muscle flap or an effective treatment for RVF.

[Locally Advanced Rectal Cancer Presenting with Perforation That Was Successfully Resected after Preoperative Chemotherapy with mFOLFOX6 plus Panitumumab]

We report a case of locally advanced rectal cancer presenting with perforation that was successfully resected after preoperative chemotherapy. A 66-year-old woman visited our emergency room complaining of lower abdominal pain. Abdominal CT showed a rectal tumor with fluid collection and free air in the pelvis. The patient was diagnosed with panperitonitis secondary to cancerous perforation and underwent sigmoid colostomy. A biopsy specimen of the rectal tumor showed well-differentiated tubular adenocarcinoma and wild-type RAS. After 8 courses of mFOLFOX6 plus panitumumab, the tumor shrank remarkably, and radical surgery(low anterior resection with D3 lymph node dissection)was performed. Microscopic examination of the resected specimen showed that almost half of the tumor cells were replaced by histiocytes and necrotic tissue. Preoperative chemotherapy with panitumumab may be an effective treatment for RAS wild-type locally advanced colon cancer, even if the primary tumor develops perforation.

[Nephrotic Syndrome Induced by Ramucirumab for Metastatic Rectal Cancer]

We report a case of nephrotic syndrome induced by ramucirumab for metastatic rectal cancer. A 48-year old woman who had received FOLFIRI plus ramucirumab for rectal cancer with liver, lung, and bone metastases presented to our hospital with edema and increased body weight. Laboratory studies showed hypoalbuminemia and severe proteinuria, and the patient was diagnosed with nephrotic syndrome. After administration of an angiotensin II receptor blocker and thiazide diuretic, her symptoms disappeared and serum albumin level normalized. To the best of our knowledge, this is the first detailed report of nephrotic syndrome related to ramucirumab. This case serves to emphasize that the possibility of nephrotic syndrome should be considered during anti-vascular endothelial growth factor therapy.

Development of a direct mechanical left ventricular assist device for left ventricular failure

We have developed a direct mechanical left ventricular assist device (DMLVAD) for severe left ventricular failure. The DMLVAD was attached to the left ventricle and compressed the heart by a pneumatic driving unit. In a mock circulation model with an extracted nonbeating heart, a cardiac output (CO) of 1.93 L/min was obtained at a driving pressure of 200 mm Hg. In a canine left ventricular failure model induced by injection of sodium hydroxide into the myocardium, the systolic arterial pressure, systolic left ventricular pressure, maximum LV dP/dt, peak flow, and CO increased by 21, 24, 58, 144, and 37%, respectively. The mean left atrial pressure also decreased by 15% when the DMLVAD was driven. These effects were most prominent when the mean left atrial pressure was over 15 mm Hg, and the driving pressure was over 100 mm Hg. Compression at late systole was more effective in obtaining greater CO. We suggest that the DMLVAD could be an optional circulatory assist device for patients with left ventricular failure awaiting heart transplantation.

Trial manufacture of eccentric roller type total artificial heart

Working toward a completely implantable total artificial heart, we have designed an eccentric roller type total artificial heart. The actuator of this artificial heart is a drum type eccentric roller that squeezes the blood chambers. The blood chambers are made of silicone rubber and are torus in shape. The shape of the artificial heart is an almost circular cylinder, and its length and diameter are 10 cm and 8 cm, respectively. The 2 main characteristics of this artificial heart are that it discharges blood in a pulsatile mode and that it requires no reversing of the motor. Because we have not completed the artificial heart yet, we have tested the eccentric roller mechanism on the prototype with an overflow type mock circulation with a 100 mm Hg afterload. The prototype worked at the roller speeds of 50, 100, and 150 rpm with flow rates of 1.7, 3.7, and 5.4 L/min, respectively. Next the prototype was connected to a Donovan type mock circulatory system and worked at roller speeds of 88-214 rpm with flow rates of 3.0-8.4 L/min against mean afterloads of 82-120 mm Hg.

Numerical simulation of nonpulsatile left ventricular bypass

A computer simulation was carried out to investigate the influence of nonpulsatile left ventricular assistance on hemodynamics. A simulation circuit was constructed to represent the circulatory system. A source of current was added to denote the nonpulsatile blood pump. The left and right ventricles were replaced by variable compliances. Left heart failure was simulated by decreasing the amount of compliance change of the left ventricle. We introduced a pulsatility indicator (PI) to clarify the pulsatility characteristics in the hemodynamics; this PI was defined as the ratio of the pulse pressure (PP) to the mean aortic pressure (AoP). When nonpulsatile bypass flow increased, the mean AoP, tension time index (TTI), and diastolic pressure time index (DPTI) increased, and cardiac output, PP, and PI decreased. When assisted flow increased with the constant total flow rate, the mean AoP and DPTI changed little; the PP, TTI, and PI decreased, and the endocardial viability rate increased. The PI would be helpful in evaluating the effect of pulsatility.

Pulsatile total artificial heart using a reversible rotary pump

A pump circuit was assembled and examined for use as an implantable artificial heart. The circuit consisted of a gear pump and 4 artificial heart valves. Mitral and pulmonary arterial valves were placed at the inflow port of the pump, and aortic and tricuspid valves were placed at the outflow port. The mitral and the tricuspid valves were connected to each reservoir at 10 mm Hg, and the aortic and the pulmonary arterial valves were connected to the head tanks at 80 and 20 mm Hg, respectively. The pump discharged pulsatile flows into both systemic and pulmonary arteries alternately by switching the direction of rotation periodically. Because the rated discharge was 1.7 L/min for the gear pump used, the measured flow rate was 0.8-0.75 L/min at a heart rate of 60-110 bpm.

[A case of right adrenal myelolipoma diagnosed preoperatively and review of literature in Japan]

Fifty-nine years old female who complained of right back pain was diagnosed as having right adrenal myelolipoma preoperatively by ultrasound, CT and other examinations. The patient was cured by surgery. The resected tumor was 11.5 X 10.5 X 8.5 cm in size and 470 g in weight. Histopathological diagnosis was myelolipoma of Soós's type 1. Sixteen cases of myelolipoma, including our case have been reported in Japanese literature. The age of patients ranged from 20 to 60 (average 49.1) and male-female ratio was 11:5. Most patients presented with abdominal pain and abdominal mass, and had complication of obesity and hypertension. The lesion was more common on the right side (11:5). Their size was 3-21 cm (average 10.9 cm) and their weight was 10-1, 930 g (average 823 g). Adrenal myelolipoma can be certainly diagnosed preoperatively by ultrasound, CT and other examinations. Adrenal tumors showing normal adrenal endocrine function and fat density on CT examination indicate that they could be myelolipoma in their nature.