U. Hildebrandt

Preoperative staging of rectal cancer by intrarectal ultrasound

Digital examination and computed tomography are the current modalities employed to assess the depth of invasion of rectal cancer. Each technique has limitations in that high rectal tumors cannot be examined digitally and CT is unable to detect small tumors. However, preoperative diagnostic capability can be improved with the use of intrarectal ultrasound. We have examined 25 patients with rectal cancer preoperatively with digital examination and intrarectal ultrasound. In order to determine the accuracy of the ultrasonic method, we compared the results to the histopathologic findings of the excised specimen. Digital examination was essentially impossible in eight of the 25 rectal tumors because the tumors were either unreachable or could not be palpated in their full longitudinal extent. Of the remaining 17, digital examination corresponded with pathologic findings in 15, while tumor spread was overestimated in two patients. Sonography corresponded with pathologic findings in 23 of the 25 tumors. Two had been overstaged. Analogous to the TNM classification for postoperative pathologic tumor staging, we propose a preoperative tumor staging based on ultrasonic determination of the infiltrative depth of tumor, which we call u TNM.

Endorectal ultrasound: instrumentation and clinical aspects

During the period 1983 to April 1986, 129 patients with rectal cancer were treated. In 76 of these depth of penetration of the rectal wall by tumour was assessed by ultrasound. T stage determined by ultrasound (uT) corresponded with the pathological stages (pT) in 67 patients. In the remaining 9 cases, ultrasound overstaged the tumour and in only one patient was the growth understaged. Lymph nodes could be visualised in 12 out of 27 patients in whom nodes were looked for but only six cases were found to be positive on histological examination. Of 22 recurrences detected or proven by ultrasound there was a group of 6 patients who had no other sign of recurrence.

Endosonography of pararectal lymph nodes

One hundred thirteen patients with carcinoma of the rectum were evaluated for lymph node metastases by endorectal ultrasound. With the use of 7.5 MHz and based on different echo patterns, two main groups of lymph nodes can be differentiated: hypoechoic and hyperechoic lymph nodes. Compared with pathologic findings, hypoechoic lymph nodes represent metastases, whereas hyperechoic lymph nodes are visualized due to unspecific inflammation. Lymph node metastases can be predicted with a sensitivity of 72 percent and inflammatory lymph nodes with a specificity of 83 percent. The physical basis of the differentiation of lymph nodes was assessedin vitroby the determination of ultrasound parameters (speed of sound, acoustic impedance, attenuation, and backscattered amplitude). The attenuation coefficient of benign lymph nodes [2.5 dB/(MHz×cm)] is significantly higher than the mean value of lymph node metastases [1.3 db/(MHz×cm)]. The results demonstrate that involved nodes can principally be differentiated from not involved nodes. Micrometastases, mixed lymph nodes, and changing echo patterns within inflammatory nodes explain the accuracy rate of 78 percent.

Computed tomography versus endosonography in the staging of rectal carcinoma: a comparative study.

In 29 patients the accuracy of computed tomography (CT) and endosonography were compared for preoperative staging of rectal cancer. CT and endosonography were both reasonably accurate, CT overstaged 6 and understaged one lesion. Endosonography overstaged only 2 cancers. The accuracy of lymph node staging is still not resolved.

Loss of physiologic hepatic blood flow control ("hepatic arterial buffer response") during CO2-pneumoperitoneum in the rat.

We analyzed whether a compensatory increase of hepatic arterial (HA) flow, known as the “hepatic arterial buffer response” (HABR), may serve for maintenance of liver blood supply during laparoscopy-associated portal venous (PV) flow reduction. We assessed HA and PV flow, as well as hepatic tissue oxygenation (Po2) during CO2-pneumoperitoneum in anesthetized and mechanically ventilated Sprague-Dawley rats (n = 7). Control animals (n = 7) without pneumoperitoneum, but tourniquet-induced PV flow reduction served to demonstrate physiologic HABR. Although stepwise tourniquet-induced reduction of PV flow to 20% of baseline values led to a significant (P < 0.05) increase of HA flow from 4.3 ± 0.7 mL/min to 9.9 ± 1.7 mL/min, stepwise intraabdominal pressure-induced decrease of PV flow was paralleled by a linear reduction of HA flow from 2.4 ± 0.3 mL/min to 1.2 ± 0.5 mL/min at 18 mm Hg intraabdominal pressure. This loss of HABR was sustained during a subsequent 2 h-period of CO2- pneumoperitoneum contrasting the 2 h of maintenance of HABR in controls. Hepatic tissue Po2 decreased during the 2 h-period of pressure- and tourniquet-induced PV flow reduction by 35% to 51%, respectively. On tourniquet release, all variables regained baseline values, whereas evacuation of the pneumoperitoneum allowed all variables except hepatic Po2 to return to baseline, indicating prolonged tissue hypoxia despite restored total liver blood flow in the Laparoscopic group. Concomitantly, increased liver enzyme activities reflected moderate tissue damage after 2 h of pneumoperitoneum. In conclusion, intraabdominal CO2- insufflation-induced hemodynamic alterations may impair tissue oxygenation and enzyme release, indicating the potential risk for hepatic tissue damage after prolonged periods of laparoscopic interventions.

Granulocyte elastase and systemic cytokine response after laparoscopic-assisted and open resections in Crohn's disease

PURPOSE: The aim of this study was to assess whether systemic proinflammatory cytokines (IL-6), anti-inflammatory cytokines (IL-4, IL-10), acute phase proteins (C-reactive protein), or granulocyte elastase are valuable indicators for determining the degree of surgical trauma after openvs. laparoscopic-assisted resections in Crohns disease. METHOD: Eleven patients in each group (open and laparoscopic-assisted surgery) were matched for indication, surgical procedure, and Crohns disease activity index. Serum IL-4, IL-6, and IL-10 were measured using enzyme-linked immunosorbent assay. Serum C-reactive protein was determined by immunoturbidimetric assay. Plasma granulocyte elastase was determined by immunoactivation immunoassay. Blood was sampled preoperatively, six hours after the operation, and at postoperative Days 1 to 5. RESULTS: IL-4 was not detectable in any sample analyzed. Serum IL-6 and IL-10 levels peaked postoperatively in both groups without significant differences between laparoscopic-assisted (185.6±54.1 pg/ml and 112.1±19.4 pg/ml, respectively; mean ± standard error of the mean) and open surgery (431.1±240.4 pg/ml and 196.7±56.5pg/ml, respectively). Serum C-reactive protein levels also rose postoperatively, with a peak on the second day, but showed similar values after laparoscopic-assisted (107.1±12.1 mg/l) and open (128.3±17.5 mg/l) surgery. Plasma granulocyte elastase levels peaked on the first and second postoperative day and were found elevated almost throughout the five-day observation period. Comparison between the groups revealed significantly (P<0.02) lower values after laparoscopic-assisted (Day 1, 46.5±8.9 µg/l; Day 2, 41.9±5.9 µg/l) when compared with open surgery (Day 1, 89.7±13.8 µg/l; Day 2, 91.4±14). CONCLUSIONS: Serum IL-6 and IL-10 may not be ideal measures for evaluation of the degree of tissue trauma in laparoscopic-assisted and open resections in Crohns disease, probably because of interference with disease-specific cytokine interactions. In contrast, granulocyte elastase has to be considered a strong marker discriminating the different severity of surgical trauma induced by laparoscopic-assistedvs. open resection in Crohns disease.

An Atlas of rectal endosonography

Clinical Staging. Radiological Staging and History. Instrumentation and Examination Technique. Anatomy. Primary Rectal Cancer. Local Recurrence. Benign Rectal Tumours, Anal Canal, Perianal Disease and Other Condition.

Single-surgeon surgery in laparoscopic colonie resection

PurposeShort-term benefits have been demonstrated for laparoscopic-assisted colectomy. However, minimally invasive surgery is still in an evolutionary phase. In demonstrating that robotic devices also are useful in laparoscopic colonie surgery, it is fundamental to prove that a single surgeon can perform almost the entire operation on his own. METHODS: A single surgeon performed forty-one, laparoscopic-assisted, colorectal resections with the assistance of a robotic device (Automated Endoscopie System for Optimal Positioning, Computer MotionTM) maneuvering the laparoscope. A surgical assistant was included only for the open part of the operation. Main outcome measures were conversion rate, total operating time, and percentage of assistance by a second surgeon. RESULTS: There were no intraoperative complications, one case of conversion to open surgery, and three postoperative complications. The total operating time ranged from 126 to 252 minutes. A single surgeon with the assistance of a robotic device was able to perform approximately 70 percent of an ileocecal resection, 70 percent of a right hemicolectomy, 80 percent of a sigmoid resection, and 85 percent of a anterior rectal resection without further help of a surgeon. CONCLUSIONS: A single surgeon with the assistance of a computerized robotic system can complete at least two-thirds of a laparoscopic-assisted, colorectal resection on his own. The use of a robotic device in laparoscopic-assisted, colonie surgery is safe, efficient, and feasible, and will proven even more so in future. This also will result in a patient-driven demand for high-standard, minimally invasive surgery.

Cardiopulmonary dysfunction during minimally invasive thoraco-lumboendoscopic spine surgery

UNLABELLED The endoscopic retroperitoneal approach to thoracolumbar anterior spine fusion is associated with CO2 insufflation into the thoracic space. We studied the cardiopulmonary effects of this CO2 thoraco-retroperitoneal insufflation compared with the conventional open surgical procedure using thoraco-phreno-lumbotomy in 12 pigs under balanced anesthesia, paralysis, and mechanical ventilation. During open surgery of the thoracolumbar spine, animals exhibited unchanged systemic and pulmonary hemodynamics, as well as ventilation and oxygenation variables. Animals retroperitoneally insufflated with CO2 (12 mm Hg) exhibited a significant increase of PaCO2 and a moderate decrease of PaO2, SaO2, and pH, with insignificant changes of central venous filling pressures and systemic hemodynamics. Endoscopic phrenotomy with thoracic CO2 insufflation instantaneously and drastically affected hemodynamic status and pulmonary gas exchange with marked hypoxia, hypercapnia, systemic hypotension, tachycardia, and pulmonary hypertension within minutes. An increase of minute ventilation, inspiratory oxygen fraction, and positive end-expiratory pressure promptly reversed these cardiopulmonary effects. CO2 evacuation allowed the animals to completely recover and regain almost baseline cardiopulmonary status, except for a reduced arterial blood pressure. Appropriate monitoring and immediate CO2 desufflation may be beneficial in cases of therapy-resistant hemodynamic, oxygenation, and ventilation difficulties. IMPLICATIONS For endoscopic thoraco-lumbar spine fusion, CO2 thoraco-retroperitoneum-induced cardiopulmonary dysfunction must be of concern, especially in patients with cardiopulmonary compromise. Appropriate monitoring and immediate CO2 desufflation may be beneficial in cases of therapy-resistant hemodynamic, oxygenation, and ventilation difficulties.

Local curative treatment of rectal cancer

Radical surgery including the removal of the tumour with wide margins of clearance and en bloc dissection of the lymphatic drainage is the operation of choice for rectal cancer. In cases where the gold standard of oncologically directed surgery can only be achieved by abdominoperineal excision, a significant mortality and morbidity will be encountered. A price is paid by the patient for cure in physical discomfort and psychological trauma. This is the result of a somewhat uniform philosophy in the treatment of rectal cancer, namely, to save life at all costs. It is now time to look more closely at the alternatives. Far more emphasis should be placed on the quality of life in older and multimorbid patients. The alternative of local surgery in early rectal cancer is attractive as sphincter function is preserved and a permanent colostomy avoided. The local therapy of rectal cancer, however, is restricted to tumours that have favourable features and these must be defined.