Prediction of surgical difficulty in minimally invasive surgery for rectal cancer by use of MRI pelvimetry.

BACKGROUND: Technical difficulties in rectal surgery are often related to dissection in a limited surgical field. This study investigated the clinical value of MRI pelvimetry in the prediction of surgical difficulty associated with minimally invasive rectal surgery. METHODS: Patients with rectal cancer who underwent laparoscopic or robotic total mesorectal excision between 2005 and 2017 were reviewed retrospectively and categorized according to surgical difficulty on the basis of duration of surgery, conversion to an open procedure, use of the transanal approach, postoperative hospital stay, blood loss and postoperative complications. Preoperative clinical and MRI-related parameters were examined to develop a prediction model to estimate the extent of surgical difficulty, and to compare anastomotic leakage rates in the low- and high-grade surgical difficulty groups. Prognosis was investigated by calculating overall and relapse-free survival, and cumulative local and distant recurrence rates. RESULTS: Of 121 patients analysed, 104 (86·0 per cent) were categorized into the low-grade group and 17 (14·0 per cent) into the high-grade group. Multivariable analysis indicated that high-grade surgical difficulty was associated with a BMI above 25 kg/m2 (odds ratio (OR) 4·45, P = 0·033), tumour size 45 mm or more (OR 5·42, P = 0·042), anorectal angle 123° or more (OR 5·98, P = 0·028) and pelvic outlet less than 82·7 mm (OR 6·62, P = 0·048). All of these features were used to devise a four-variable scoring model to predict surgical difficulty. In patients categorized as high grade for surgical difficulty, the anastomotic leakage rate was 53 per cent (9 of 17 patients), compared with 9·6 per cent (10 of 104) in the low-grade group (P < 0·001). The high-grade group had a significantly higher local recurrence rate than the low-grade group (P = 0·002). CONCLUSION: This study highlights the impact of clinical variables and MRI pelvimetry in the prediction of surgical difficulty in minimally invasive rectal surgery.

ANTECEDENTES: Las dificultades técnicas en la cirugía del recto a menudo están relacionadas con la disección en un campo quirúrgico limitado. Este estudio se propuso investigar la utilidad clínica de la pelvimetría con MRI para predecir la dificultad quirúrgica asociada con la cirugía mínimamente invasiva del recto. MÉTODOS: Pacientes con cáncer de recto sometidos a resección total del mesorrecto laparoscópica o robótica entre 2005 y 2017 fueron revisados retrospectivamente y categorizados de acuerdo con la dificultad técnica en base al tiempo operatorio, conversión, uso de abordaje transanal, estancia hospitalaria postoperatoria, pérdida sanguínea y complicaciones postoperatorias. Se examinaron parámetros clínicos preoperatorios y relacionados con la MRI para desarrollar un modelo de predicción que estimara el grado de dificultad técnica y pudiera comparar la tasa de dehiscencias anastomóticas en los grupos de bajo y alto riesgo. También se evaluó el pronóstico con el cálculo de la supervivencia global, supervivencia libre de recidiva y tasas acumuladas de recidiva local y a distancia. RESULTADOS: De un total de 121 pacientes analizados, 104 pacientes (85,9%) fueron categorizados en el grupo con bajo grado de dificultad técnica, mientras que 17 pacientes (14,1%) lo fueron en el grupo de alto grado. En el análisis multivariable, un alto grado de dificultad técnica se asociaba con un índice de masa corporal (body mass index, BMI) > 25 kg/m2 (razón de oportunidades, odds ratio (OR), 4,5; P = 0,033), tamaño tumoral ≥ 45 mm (OR, 5,4; P = 0,042), ángulo anorrectal ≥ 123 grados (OR, 6,0; P = 0,028), estrecho pélvico < 82,7 mm (OR, 6,6; P = 0,048); en consecuencia, todas estas características fueron utilizadas para establecer un modelo de puntuación con 4 variables que pudiera predecir la dificultad técnica. En los pacientes categorizados como de alto grado de dificultad técnica, la tasa de dehiscencia anastomótica fue del 52,9%, mientras que en el grupo de bajo grado fue del 9,6% (P < 0,001). Finalmente, el grupo con alto grado mostró una tasa significativamente más elevada de recidiva local en comparación con el grupo de bajo grado (P = 0,002). CONCLUSIÓN: Este estudio pone de relieve el impacto de variables clínicas y de la pelvimetría con MRI para predecir la dificultad técnica en la cirugía mínimamente invasiva del recto.

Anterior intussusception descent during defecation is correlated with the severity of fecal incontinence in patients with rectoanal intussusception.

BACKGROUND: Rectoanal intussusception (RAI) is a common finding on evacuation proctography in patients with defecation disorders. However, it remains unclear whether intussusception morphology affects the severity of fecal incontinence (FI). The aim of this study was to examine the effect of morphology during defecation on the severity of FI in patients with RAI. METHODS: We included 80 patients with FI who were diagnosed as having RAI on evacuation proctography. Various morphological parameters were measured, and the level of RAI was divided by the extent of descent onto (level I) or into (level II) the anal sphincter. FI symptoms were documented using the FI Severity Index (FISI). RESULTS: Twenty-eight patients had level I and 52 had level II RAI. The mean (range) FISI score was 24.0 (8-47). FISI scores tended to be significantly higher in level II than in level I [26.3 (10-47) vs. 21.8 (8-42); p = 0.05]. The mean anterior intussusception descent was significantly greater in level II than in level I [24.2 (9.2-39.5) vs. 17.7 (7.8-39.4) mm; p < 0.0001]. Regression analysis showed that anterior intussusception descent was predictive of increased FISI scores. CONCLUSIONS: The severity of FI may be affected by anterior intussusception descent in patients with RAI.

Malignant peripheral nerve sheath tumor of the pancreas with perineurial cell differentiation.

The authors report a malignant peripheral nerve sheath tumor (MPNST) that developed in the body of the pancreas of a 76-year-old woman. The well-demarcated tumor, 4.5 x 3.5 cm in size, was composed of spindle-shaped cells arranged in a storiform pattern or sweeping fascicles. Ultrastructurally, the tumor cells had elongated cytoplasmic processes with numerous pinocytotic vesicles, and were covered with discontinuous basal lamina-like substances. Immunohistochemically, tumor cells were diffusely positive for epithelial membrane antigen, vimentin, and CD34, but negative for S-100 protein and Leu 7. It was therefore concluded that the tumor was a MPNST with perineurial cell differentiation. Primary MPNST of the pancreas is extremely rare and the immunohistochemical and ultrastructural studies are necessary for its diagnosis.

[A case of gastric cancer with recurrent bone metastases successfully treated with induced hypertension chemotherapy using cisplatin].

A sixty-eight-year-old female with bone metastases from gastric cancer successfully treated with induced hypertension chemotherapy using cisplatin is reported. She had undergone R2 curative subtotal gastrectomy in June 1985, and had orally taken tegafur 600 mg/day and then changed to doxifluridine 800 mg/day as postoperative adjuvant chemotherapy. Five months after the operation she had back pains and both 99mTc-MDP and 67Ga-citrate scintigram showed L1 vertebra and rib bone metastasis. Induced hypertension chemotherapy using cisplatin was then intermittently performed from January 1986 to September 1990, a single course of which was 25 mg/body div x 2/week for serial 4 weeks; a total of seven courses were carried out and consequently the total volume of the administered cisplatin reached 1,100 mg. Neither medullar nor renal toxicities were observed, but mild gastrointestinal symptoms were noted. The patient no longer has back pains, and no signs of bone metastases were seen on both scintigrams for two years and eight months from December 1988 to August 1991. This case is very rare because her bone metastases were successfully treated with induced hypertension chemotherapy using cisplatin. However, metastatic bone tumors from gastric cancer usually resist any treatments. It is expected that the successfully treated patients even with bone metastasis will be increasingly reported from now as various new approaches including induced hypertension chemotherapy are introduced.

[Clinical studies on the reaction of the skin to various doses of Su-polysaccharide in cancer patients].

The reaction of skin to 10-micrograms and 20-micrograms quantities of Su-polysaccharide (Su-Ps) were examined in 117 patients with cancer, and the results obtained were as follows. Reaction was a little greater to the 20-micrograms dose than to the 10-micrograms dose, but the two parameters were much correlated with each other. The rates of patients showing positive reactions to each dose were 30.8% for 10-micrograms and 34.2% for 20-micrograms. The reactions were augmented by administration of OK-432. The augmentation of skin reaction by OK-432 was more prominent at 20-micrograms doses than at 10-micrograms doses, therefore appearing to be Su-polysaccharide dose-dependent. The ideal Su-polysaccharide dose for Su-Ps skin reaction thus seemed to be 20-micrograms.

[Constant intra-aortic infusion chemotherapy for advanced abdominal cancer--a technic and the effect in patients with peritoneal metastases].

Constant intra-aortic infusion chemotherapy using an artificial graft was performed in 39 patients with advanced abdominal cancer. This method was easy for insertion and re-insertion of the catheter; thus it is suitable for long-term and repeated constant infusion therapy. Complications encountered with the catheter were obstruction (8 cases); cracking (4 cases); cracking of the connector (4 cases); infection of the graft (2 cases), and arterial thrombosis (1 case). Minor complications encountered upon using the catheter were solved by our method, however, infection represents a serious problem. In cases with peritoneal metastases, the response rate was excellent (43% by Karnofsky's criterion and 67% as determined by the ascitic effect) and this therapy was effective for symptoms resulting from peritoneal metastases. In conclusion, ours seems to be useful therapeutic method for advanced abdominal cancer with peritoneal metastases.

[Case of rectal cancer with high level of serum alpha-fetoprotein].

A 61 year old male with a high serum alpha-fetoprotein level (2750 ng/ml) is reported. He had undergone curative surgery for early gastric cancer in June 1979, and palliative resection of a primary rectal lesion in December 1981. The postoperative alpha-fetoprotein level decreased to 1300 ng/ml but gradually increased despite the intraarterial infusion of 5-FU (9.25g) and Mitomycin-C (30 mg). He died of cachexia in February 1982. Histological examination revealed moderately differentiated adenocarcinoma; alpha-fetoprotein positive substances were found in the cytoplasm of rectal cancer cells by the enzyme labeled antibody method(peroxidase-antiperoxidase immune complex method). This rectal cancer patient had multiple primary cancers and gastric cancer.

Viability of intraperitoneal free cancer cells in patients with gastric cancer.

The viability and morphologic changes of intraperitoneal free cancer cells in advanced gastric cancer patients were examined by Giemsa and enzymologic staining and by tritiated thymidine uptake. Although many free cancer cells in the pouch of Douglas showed moderate degeneration, viable, morphologically intact cells were noted, leading to the possibility of their implantation and proliferation in the peritoneum. Serosal cancer cells showed a high degree of viability. In patients undergoing gastric cancer surgery, the viability of free cancer cells was markedly decreased by a single intraoperative administration of 10 mg of mitomycin C (MMC) to the pouch of Douglas, suggesting that this may represent an effective means of preventing peritoneal dissemination.

Morphogenesis of peritoneal metastasis in human gastric cancer.

A comparative light microscopic and scanning electron microscopic study of the morphogenesis of peritoneal metastasis in 34 human gastric cancers was performed. Prior to adhesion of gastric cancer cells to the peritoneum, the mesothelial cells became hemispherical and exfoliated from the peritoneum, and gastric cancer cells adhered to the naked areas of the submesothelial connective tissue. A flat metastatic tumor was formed by cancer cell proliferation in the shallow region of the peritoneum. Subsequently, after the infiltration of cancer cells into the connective and adipose tissue, the formation of a large tumor mass was observed. There was a correlation between the surface and histological structure of the metastatic tumors. In poorly differentiated cancer, the cells were isolated while in differentiated cancer, they formed nodules with indistinguishable cell boundaries.

A scanning electron microscopic study on the peritoneal implantation of ascites hepatoma AH100B cells in rats.

The process and mechanism of peritoneal metastasis of tumor cells were studied experimentally by means of scanning or transmission electron microscopy, employing rat ascites hepatoma AH100B. Adhesion of tumor cells by microvilli and/or pseudopodia to the mesothelium was observed within 1 approximately 3 days after inoculation when there was no morphological changes of the mesothelial cells. Some changes of the mesothelial cells, such as irregularity, atrophy, and exfoliation, followed tumor cell adhesion 5 or 6 days after inoculation. It was noted that tumor cells adhered to the mesothelium first where no morphological changes were induced, and it is suggested that tumor cells infiltrate into the submesothelial tissue through mesothelial defects.