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Alfred Cuschieri

Publications and source records attributed to Alfred Cuschieri.

At least 19 recordsLinked to original sources
PubMed2003

Evolution of a percutaneous fetoscopic access system for single-port tracheal occlusion.

BACKGROUND/PURPOSE: Prenatal tracheal occlusion currently is being assessed as a treatment modality for congenital diaphragmatic hernia (CDH). The development of a totally percutaneous fetoscopic access system would help avoid the need for maternal laparotomy and reduce the morbidity rate of fetal surgical procedures for the mother. Laparoscopic radial expansion sheaths and Seldinger technique-based vascular catheters both have been advocated as means of achieving amniotic cavity access. The authors have investigated these 2 systems in an attempt to develop a reliable method for achieving safe percutaneous fetoscopic access and present the first successful attempt to deploy an intratracheal balloon using an entirely percutaneous approach through a single port in an ovine model. METHODS: A number of prototype systems were evaluated sequentially over a 3-year period in an ovine model: (1) the radially expanding InnerDyne step port system, (2) a new rigid cannula with a bulbous/sharp end preloaded onto the radially expanding InnerDyne port, (3) a conical removable addition to the rigid cannula in 2, (4) a modified bulbous/sharp ended cannula incorporating a circumferential protective insert, (5) a rigid split sheath with the radially expanding port placed through the lumen of the split sheath, (6) a flexible introducer and dilator with the split sheath (used in the Seldinger placement of central lines), and (7) a 2-needle approach using a superelastic shape-memory alloy Nickel-Titanium wire with the flexible dilator and sheath, incorporating a side perfusion port. For balloon tracheal occlusion, live anaesthetized time-mated pregnant ewes were used at 110 days' gestation. Tracheobronchoscopy was achieved using a 3-mm 0 degrees telescope, and the cutaneotracheal tract was secured by a 3.3-mm sheath incorporating a side-perfusion port. The rigid telescope was replaced by a flexible choledochoscope preloaded with a silicone balloon. The balloon was deployed 2 cm above the carina proximal to the right upper lobe bronchus. RESULTS: The many problems encountered in the evolution of the preferred system related mainly to separation and tenting of the chorioamniotic membranes in the ovine uterus and inconsistent access to the fetal parts of interest. Each resulted in significant modifications to our approach. Furthermore, the use of rigid access devices commonly caused fetal injury. Successful access to the intrauterine cavity and cannulation of the trachea was achieved consistently with minimal trauma, irrespective of fetal position by method 7. Multiple port placement allowed visualization of the entry of all components of the system confirming minimal chorioamniotic membrane separation and tenting. Single port tracheal occlusion was undertaken first on 6 cadavers before being performed successfully on 3 live anaesthetized ewes. Fetoscopic access and cannulation of the trachea was achieved consistently in all live animals irrespective of fetal position. CONCLUSIONS: This modified Seldinger technique using the unique properties of the memory-shaped alloy wire for initial uterine access offers a safe method for the percutaneous placement of fetoscopic ports in the ovine model for prenatal intervention. Successful placement of a tracheal balloon entirely through a single percutaneously placed port represents a further advance in prenatal therapy for CDH.

Animals↗
PubMed2003

How safe is high-power ultrasonic dissection?

OBJECTIVE: To evaluate the safety of ultrasonic dissection. SUMMARY BACKGROUND DATA: High-power ultrasonic dissection is in widespread use for both open and laparoscopic operations and is generally perceived to carry a low risk of collateral damage, but there is no published evidence for this. METHODS: Under controlled experimental conditions, ultrasonic dissections were performed in pigs using Ultracision (Ethicon) or Autosonix (Tyco/USSC) at the three power settings (3, 4, and 5) in random fashion to mobilize the cardia and fundus, bile duct, hepatic artery, portal vein, aorta from the inferior vena cava, renal vessels, colon, and ureters. The dissections (open and laparoscopic) were carried out on pigs at each power setting with each device. Thermal mapping of the tissues during dissection was performed with an infrared thermal camera and associated software. The animals were killed at the end of each experiment and specimens were harvested for quantitative histology. RESULTS: Extreme and equivalent temperature gradients were generated by ultrasonic dissection with both systems. Heat production was directly proportional to the power setting and the activation time. The core body temperature of the animals after completion of the laparoscopic dissections rose by an average of 2.3 degrees C. The zone around the jaws that exceeded 60 degrees C with continuous ultrasonic dissection for 10 to 15 seconds at level 5 measured 25.3 and 25.7 mm for Ultracision and Autosonix, respectively. At this power setting and an activation time of 15 seconds, the temperature 1.0 cm away from the tips of the instrument exceeded 140 degrees C. Although there was no discernible macroscopic damage, these thermal changes were accompanied by significant histologic injury that extended to the media of large vessels and caused partial- to full-thickness mural damage of the cardia, ureter, and bile duct. Collateral damage was absent or insignificant after dissections at power level 3 with both systems and an activation time not exceeding 5 seconds. CONCLUSIONS: High-power ultrasonic dissections at level 5 and to a lesser extent level 4 result in considerable heat production that causes proximity collateral damage to adjacent tissues when the continuous activation time exceeds 10 seconds. Ultrasonic dissections near important structures should be conducted at level 3. At power levels of 4 and 5, the ultrasonic energy bursts to the tissue should not exceed 5 seconds at any one time.

Animals↗
PubMed2002

Anorectal anomalies associated with or as part of other anomalies.

Anorectal anomalies occurring with other anomalies or as part of syndromes were analyzed to determine how their epidemiological characteristics differed from those of isolated anal anomalies. Almost 15% of cases were chromosomal, monogenic or teratogenic syndromes, whereas the rest were of unknown cause including sequences (9.3%), VACTERL associations (15.4%) and multiple congenital anomalies (MCA) (60.2%). Almost half of babies with MCA had one or two VACTERL anomalies with distribution frequencies that did not differ significantly from those in babies with the full VACTERL association. There were considerable differences in the frequency of the VACTERL association among babies with different types of anorectal anomaly. Babies with anal anomalies occurring with sequences, VACTERL or MCA showed the same sex differences as babies with isolated anal anomalies, namely male predominance in anal atresia without fistula or cloaca, no sex difference in anal atresia with fistula, and female predominance in ectopic anus and congenital anal fistula. These anomalies, however, were associated with significantly lower mean gestational lengths and birth weights, and higher frequencies of fetal death and pregnancy termination than babies with isolated anal anomalies. Twins were more frequent in sequences, VACTERL and MCA than in isolated anomalies, monogenic syndromes or chromosome anomalies. Five cases were conjoined twins, representing 15% of all cases of twin pregnancies with an anal anomaly. Indeterminate sex was more frequent in babies with anal atresias without fistula than in those with fistula. Anal anomalies are defects of blastogenesis attributable to disorders in expression of pattern determining genes. The differential sex involvement in different types of anal anomaly may be manifestations of expression of the HY/SRY genes during blastogenesis or of X-linkage.

Abnormalities, Multiple↗
PubMed2002

Shadow depth cues and endoscopic task performance.

HYPOTHESIS: A shadow-inducing laparoscopic system improves task performance. DESIGN: Experimental study was carried out using the Dundee Endoscopic Psychomotor Tester for objective assessment of task performance. The standard exercise consisted of passing a probe through 37 holes on the target plate in a random order. Shadow was induced by using separate ports for illumination and imaging of the target plate. Light direction-to-target (LDT) angles of 90 degrees, 75 degrees, and 60 degrees were investigated with each of the 90 degrees and 75 degrees optical axis-to-target view angles. SETTING: Research laboratory at the Surgical Skills Unit, Ninewells Hospital. PARTICIPANTS: Twenty medical students with no previous exposure to laparoscopic surgery. MAIN OUTCOME MEASURES: Success score, execution time, the force applied on the target, and angular deviations of the probe. RESULTS: With a 90 degrees optical axis-to-target angle, there was improvement in the success score using either 75 degrees or 60 degrees LDT angles compared with a 90 degrees LDT angle (P =.02, P =.01, respectively), but the execution time became longer (P =.008, P =.03, respectively). With a 75 degrees optical axis-to-target angle, there was improvement in the success score (P<.001), execution time (P<.001, P =.03, respectively), and horizontal and vertical deviations (P<.001) on using either 90 degrees or 60 degrees LDT angles compared with a 75 degrees LDT angle. CONCLUSION: Endoscopic task performance significantly improves with a system that provides illumination and shadows in the operative field.

Cues↗
PubMed2002

The performance of master surgeons on the Advanced Dundee Endoscopic Psychomotor Tester: contrast validity study.

HYPOTHESIS: The contrast validity of the Advanced Dundee Endoscopic Psychomotor Tester (ADEPT) was determined by comparing the performance of "master surgeons" with that of surgical trainees (also called junior surgeons) on the system. DESIGN: Twenty master surgeons and 20 junior surgeons were tested on the ADEPT system. The master surgeons, all of consultant grade, were recruited as established experts of national or international standing in laparoscopic surgery. The junior surgeons were participants of essential laparoscopic courses at the start of their higher surgical training. The ADEPT end points used in the study were instrument error, execution time, and task completion. An analysis of variance was used for the data analysis, with statistical significance set at.05. RESULTS: Master surgeons incurred a significantly lower instrument error rate than surgical trainees (P =.007), with no significant difference in execution time and the task completion score (P =.42 and P =.40, respectively). CONCLUSION: The ADEPT system has contrast validity because master surgeons completed the tasks more accurately without sacrificing execution time.

Adult↗
PubMed2002

Pancreatic necrosis: pathogenesis and endoscopic management.

This review outlines advances in our understanding of the pathogenesis of severe acute pancreatitis. It reviews the current general management of these patient and the various advances in the endoscopic treatment approaches for patients with infected pancreatic necrosis and those who do not improve on conservative management. The technique of laparoscopic infracolic pancreatic necrosectomy and irrigation of the lesser sac is described in detail.

Endoscopy↗