Open versus robotic-assisted transabdominal preperitoneal (R-TAPP) inguinal hernia repair: a multicenter matched analysis of clinical outcomes

PURPOSE

To compare the perioperative outcomes of initial, consecutive robotic-assisted transabdominal preperitoneal (R-TAPP) inguinal hernia repair (IHR) cases with consecutive open cases completed by the same surgeons.

METHODS

Multicenter, retrospective, comparative study of perioperative results from open and robotic IHR using standard univariate and multivariate regression analyses for propensity score matched (1:1) cohorts.

RESULTS

Seven general surgeons at six institutions contributed 602 consecutive open IHR and 652 consecutive R-TAPP IHR cases. Baseline patient characteristics in the unmatched groups were similar with the exception of previous abdominal surgery and all baseline characteristics were comparable in the matched cohorts. In matched analyses, postoperative complications prior to discharge were comparable. However, from post discharge through 30 days, fewer patients experienced complications in the R-TAPP group than in the open group [4.3% vs 7.7% (p = 0.047)]. The R-TAPP group had no reoperations post discharge through 30 days of follow-up compared with five patients (1.1%) in the open group (p = 0.062), respectively. Multivariate logistic regression analysis which demonstrated patient age > 65 years and the open approach were risk factors for complications within 30 days post discharge in the matched group [age > 65 years: odds ratio (OR) = 3.33 (95% CI 1.89, 5.87; p < 0.0001); open approach: OR = 1.89 (95% CI 1.05, 3.38; p = 0.031)].

CONCLUSIONS

In this matched analysis, R-TAPP provides similar postoperative complications prior to discharge and a lower rate of postoperative complications through 30 days compared to open repair. R-TAPP is a promising and reproducible approach, and may facilitate adoption of minimally invasive repairs of inguinal hernias.

Residual human immunodeficiency virus (HIV) Type 1 RNA and DNA in lymph nodes and HIV RNA in genital secretions and in cerebrospinal fluid after suppression of viremia for 2 years

Residual viral replication persists in a significant proportion of human immunodeficiency virus (HIV)-infected patients receiving potent antiretroviral therapy. To determine the source of this virus, levels of HIV RNA and DNA from lymphoid tissues and levels of viral RNA in serum, cerebrospinal fluid (CSF), and genital secretions in 28 patients treated for < or =2.5 years with indinavir, zidovudine, and lamivudine were examined. Both HIV RNA and DNA remained detectable in all lymph nodes. In contrast, HIV RNA was not detected in 20 of 23 genital secretions or in any of 13 CSF samples after 2 years of treatment. HIV envelope sequence data from plasma and lymph nodes from 4 patients demonstrated sequence divergence, which suggests varying degrees of residual viral replication in 3 and absence in 1 patient. In patients receiving potent antiretroviral therapy, the greatest virus burden may continue to be in lymphoid tissues rather than in central nervous system or genitourinary compartments.

An orthotopic mouse model of remetastasis of human colon cancer liver metastasis

Whether liver metastases from colon cancer are capable of metastasizing to other sites is an important question in surgical oncology. To answer this question, we have developed a highly metastatic orthotopic transplant model of a liver metastasis from a human colon cancer patient in nude mice that targets the liver and lymph nodes. The metastatic human tumor was transplanted in athymic nude mice by surgical orthotopic implantation (SOI) of a liver metastasis from a colon cancer patient. The human colon tumor was then subsequently implanted in the colon by SOI or, in an additional series of nude mice, in the liver by surgical hepatic implantation (SHI). The mice were then explored over time for lymph node involvement beginning 10 days after implantation. After SOI, 100% of the animals had liver metastasis within 10 days, and subsequently, 19 days after SOI, all lymph nodes draining the liver were involved with metastasis without any retroperitoneal or lung tissue involvement. After SHI, all sites of lymphatic drainage of the liver, including portal, celiac, and mediastinal lymph nodes, were massively involved by metastasis in 100% of the animals as early as 10 days after tumor implantation on the liver. The results of this study demonstrate that liver metastases from colon cancer are capable of remetastasizing to other sites. This study thus suggests that in colon cancer patients with liver metastasis, mediastinal, celiac, and portal lymph node metastases originate from the liver metastasis and not, as previously thought, from primary colon cancer.

Fecal continence following partial resection of the anal canal in distal rectal cancer: long-term results after coloanal anastomoses

BACKGROUND

The aim of the study was to assess the influence of partial excision of the superior portion of the anal canal (AC) when necessary for tumor margin clearance in distal rectal cancer on fecal continence after coloanal anastomoses.

METHODS

Between 1977 to 1993, 209 patients with middle and lower third rectal cancers underwent complete rectal excision and coloanal anastomoses. For very low tumors, located at or below 5 cm from the anal verge (AV), varying portions of the superior segment of the AC were excised for tumor margin clearance. The magnitude of resections was inversely proportional to the height of the anastomosis from the AV. The patients were categorized into 3 groups according to their level of anastomoses from AV: group 1, patients with anastomoses from 0.5 to less than 2 cm from AV (1 to 2.5 cm of AC resected, i.e., major resection); group 2, anastomoses at 2 to less than 3 cm from AV (less than 1 cm of AC resected, i.e., minor resection); group 3, with anastomoses at 3 to 3.5 cm from AV (AC completely preserved). A standard questionnaire, physical examination, and anal manometry at intervals of 3, 6, 12, 24, 36, and 48 months were performed prospectively to assess anal continence.

RESULTS

The patients in the 3 categories were matched for age, gender, stage, presence or absence of a colonic J-pouch, preoperative neoadjuvant radiotherapy and surgical technique. Fourteen patients with postoperative radiotherapy were excluded from the clinical assessment. Mean follow-up was 33.5 months. There were 43 patients in group 1, 75 in group 2, and 73 in group 3 for clinical assessment. In the first year, there was progressive improvement in anal continence in all 3 groups. At 2 years, 50% in group 1, 73% in group 2, and 62% in group 3 were fully continent. The proportion of patients fully continent in group 1 remained unchanged as compared to continued improvement for groups 2 and 3 following the first year. At 4 years, 50% in group 1, 80% in group 2, and 68% in group 3 were completely continent. The difference among the 3 groups was not statistically significant.

CONCLUSIONS

For distal rectal cancer, where tumor margin clearance necessitates partial resection of the superior portion of the AC, when limited to less than 1 cm, the proportion of patients remaining fully continent is similar to those with complete AC preservation. More substantial excisions of the AC can still result in satisfactory anal continence, such that following the fourth year, one half of the patients can expect to be fully continent.

A nude mouse model of massive liver and lymph node metastasis of human colon cancer

Liver and lymph nodes metastasis are the main causes of treatment failure for advanced colon cancer. However, currently-available animal models of human colon cancer do not demonstrate sufficient metastasis to represent highly malignant colon cancer that extensively metastasizes to these sites. A liver metastasis from a patient with highly malignant, poorly differentiated adenocarcinoma of the colon was established in nude mice by surgical orthotopic implantation to the mouse colon. The human origin of the tumor growing in nude mice was confirmed by in situ hybridization of human DNA. After 20 passages from the first implantation, massive liver and lymph nodes metastasis, occurred in 100% of the transplanted animals. Lymph nodes metastasis were found at the sites of lymph node drainage of the liver: celiac, portal and mediastinal lymph nodes. However no mesenteric and retroperitoneal nodes or lung tissue metastases were observed. Our data suggest that the mediastinal, celiac and hepatic lymph nodes metastases are derived form the liver metastasis, confirming the concept of metastasis of metastases or "remetastasis" of colon cancer.

An ultra-metastatic model of human colon cancer in nude mice

An ultra-high metastatic model of human colon cancer was developed in order to represent highly malignant patient disease for which there is no current model. Surgical orthotopic implantation (SOI) of a histologically intact liver metastasis fragment derived from a surgical specimen of a patient with metastatic colon cancer was initially implanted in the colon, liver and subcutaneously in nude mice. This tumor did not metastasize for the first 10 passages. At the eleventh passage, the tumor exhibited metastasis from the colon to the liver, spleen, and lymph nodes. At this time, two selective passages were carried out by transplanting resulting liver metastases in the nude mice to the colon of additional nude mice. After these two passages, the tumor became stably ultra-metastatic and was termed AC3488UM. One-hundred percent of mice transplanted with AC3488UM with SOI to the colon exhibited local growth, regional invasion, and spontaneous metastasis to the liver, lymph nodes, and spleen. While the maximum size of the primary tumor was 0.9 g, the metastatic liver was over 9 times the weight of the normal liver with the maximum weight of the metastatic liver over 12 g. Liver metastases were detected by the tenth day after transplantation in all animals. Half the animals died of metastatic tumor 25 days after transplantation. Histological characteristics of AC3488UM tumor were poorly differentiated adenocarcinoma of colon. Mutant p53 is expressed heterogeneously in the primary tumor and more homogeneously in the liver metastasis suggesting a possible role of p53 in the liver metastasis. The human origin of AC3488UM was confirmed by positive fluorescence staining for in situ hybridization of human DNA. The AC3488 human colon-tumor model with its ultra-high metastatic capability in each transplanted animal, short latency and a short median survival period is different from any known human colon cancer model and will be an important tool for the study of and development of new therapy for highly metastatic human colon cancer.

Is rectal intussusception a cause of idiopathic incontinence?

PURPOSE

The cause of rectal intussusception in patients primarily dominated by symptoms of anal incontinence has not been fully elucidated, especially for patients with idiopathic incontinence.

METHODS

Between 1991 and 1996, 51 patients referred with a diagnosis of idiopathic incontinence were prospectively evaluated by standard questionnaire, clinical examination, defecography, and anal manometry. Fourteen female patients were identified with rectal intussusception and were treated by transabdominal rectopexy. Postoperatively, clinical assessment and anal manometry were performed at regular intervals.

RESULTS

Continence was improved after rectopexy (P < 0.01). The postoperative increases in the anal resting pressure, maximum squeeze pressure, and maximum tolerated volume were not statistically significant.

CONCLUSIONS

Rectopexy improved anal incontinence in patients with rectal intussusception. The cause of rectal intussusception in anal incontinence could not be explained by functional improvement of the internal anal sphincter tone or an increase in the maximum tolerated volume. Rectal intussusception may be a cause of idiopathic incontinence in patients; however, larger prospective studies are required to support this concept.

Prospective, randomized study comparing clinical results between small and large colonic J-pouch following coloanal anastomosis

PURPOSE

Improved functional results can be obtained by construction of a colonic J-pouch after coloanal anastomosis. Variability in pouch size following coloanal anastomosis is prevalent in current literature. In this study, the authors compare clinical bowel function after complete rectal excision with coloanal anastomosis for patients with rectal carcinoma using either a small 6-cm or a large 10-cm colonic J-pouch anastomosis. The clinical outcome is assessed both at short-term and long-term follow-up.

METHODS

Fifty-nine consecutive patients with rectal cancers 4 to 8 cm from the anal verge were recruited into the study. Patients were randomized intraoperatively to either a 6-cm J-pouch group or a 10-cm J-pouch group. Clinical assessments were performed prospectively at 3, 6, 12, and 24 months postoperatively, following colostomy closure. Clinical parameters such as frequency, urgency, continence, and laxative and enema use were assessed and compared between the two groups.

RESULTS

There was no statistical differences in the mean defecation frequency, urgency, and fecal continence between the two groups at 3, 6, 12, and 24 months. In the first year, laxative and enema use between the two groups was negligible; however at two years, 30 percent of patients with a large reservoir compared with 10 percent of patients in the small-pouch group required laxative and/or enema for constipation and evacuation of bowels.

CONCLUSION

Similar clinical results can be expected from patients with either small or large reservoirs at one year. However, with long-term follow-up, patients with a large reservoir are more likely to require medication for constipation and evacuation. To avoid these inconveniences a small reservoir is advocated for patients undergoing coloanal anastomosis.