Laparoscopic Pediatric Inguinal Hernia Repair: A Pilot Study in a Novel Guinea Pig Animal Model

Some cardiopulmonary effects of capnoperitoneum in anesthetized guinea pigs (Cavia porcellus): spontaneous ventilation versus intubation and mechanical ventilation

OBJECTIVE

To compare cardiopulmonary variables and blood gas analytes in guinea pigs (Cavia porcellus) during anesthesia with and without abdominal carbon dioxide (CO₂) insufflation at intra-abdominal pressures (IAPs) 4 and 6 mmHg, with and without endotracheal intubation.

STUDY DESIGN

Prospective experimental trial.

ANIMALS

A total of six intact female Hartley guinea pigs.

METHODS

A crossover study with sequence randomization for IAP and intubation status was used. The animals were sedated with intramuscular midazolam (1.5 mg kg^-1) and buprenorphine (0.2 mg kg^-1) and anesthetized with isoflurane, and an abdominal catheter was inserted for CO₂ insufflation. Animals with endotracheal intubation were mechanically ventilated and animals maintained using a facemask breathed spontaneously. After 15 minutes of insufflation, the following variables were obtained at each IAP: pulse rate, respiratory rate, rectal temperature, oxygen saturation, end-tidal CO₂ (intubated only), peak inspiratory pressure (intubated only), noninvasive blood pressure and blood gas and electrolyte values, with a rest period of 5 minutes between consecutive IAPs. After 4 weeks, the procedure was repeated with the guinea pigs assigned the opposite intubation status.

RESULTS

Intubated guinea pigs had significantly higher pH and lower partial pressure of CO₂ in cranial vena cava blood (PvCO₂) than nonintubated guinea pigs. An IAP of 6 mmHg resulted in a significantly higher PvCO₂ (65.9 ± 19.0 mmHg; 8.8 ± 2.5 kPa) than at 0 (53.2 ± 17.2 mmHg; 7.1 ± 2.3 kPa) and 4 mmHg (52.6 ± 10.8 mmHg; 7.01 ± 1.4 kPa), mean ± standard deviation, with intubated and nonintubated animals combined.

CONCLUSIONS AND CLINICAL RELEVANCE

Although the oral anatomy of guinea pigs makes endotracheal intubation difficult, capnoperitoneum during anesthesia induces marked hypercapnia in the absence of mechanical ventilation. An IAP of 4 mmHg should be further evaluated for laparoscopic procedures in guinea pigs because hypercapnia may be less severe than with 6 mmHg.

Subcutaneous Endoscopic-Assisted Ligation of the Internal Ring for Inguinal Hernia Repair in Neonates Under Spinal Anesthesia

Introduction: While laparoscopy is now widely accepted for inguinal hernia repair in infants, it traditionally has required general anesthesia. We sought to evaluate the safety of laparoscopic inguinal hernia repair in infants under spinal anesthesia. Materials and Methods: We performed a retrospective cohort study of all inguinal hernia repairs at a single institution between December 2011 and June 2019 in patients younger than 6 months of age. Four groups were compared: laparoscopic under general anesthesia, laparoscopic with spinal anesthesia, open with spinal anesthesia, and open under general anesthesia. Main outcome measures include operative time, cost, and postoperative outcomes. These were assessed using Kruskal-Wallis median comparison. Results: Of the 226 patients meeting inclusion criteria, 54% (122/226) of patients underwent general anesthesia, while 46% (104/226) had spinal. When compared to general anesthesia, spinal anesthesia was associated with significantly shorter procedure times (P < .01) and lower cost (P < .01) for both open and laparoscopic approaches. Complications were few and underpowered to calculate significance across each group. Conclusions: Laparoscopic inguinal hernia repair can be safely performed in infants under spinal anesthesia without significant compromise of early perioperative outcomes. Advantages may include shorter procedure time and lower cost.

Laparoscopic ovariectomy in guinea pigs: A pilot study

OBJECTIVE

To assess the feasibility and safety of laparoscopic ovariectomy in guinea pigs utilizing 3-mm minilaparoscopic instruments.

STUDY DESIGN

Experimental pilot study.

ANIMALS

Guinea pigs (n = 3).

METHODS

The guinea pigs were sedated, placed under general anesthesia, and intubated under endoscopic visualization. A 3-port technique was used with a 3.9-mm cannula for the endoscope and two 3.5-mm cannulas accommodating 3-mm endoscopic instruments including a 3-mm vessel sealing device, grasping forceps, and endoscopic scissors. The abdomen was insufflated with CO₂ to a pressure of 6-8 mm Hg. The guinea pigs were manually tilted 90° laterally to visualize the dorsally positioned ovaries.

RESULTS

The procedure was successfully performed in all 3 animals. The surgery times were 120, 45, 45 minutes for the 3 guinea pigs, and anesthesia times were 186, 90, and 76 minutes, respectively. Placing the animals in complete lateral recumbency was found to be critical to visualize and manipulate the ovaries. The guinea pigs recovered smoothly from anesthesia.

CONCLUSION

Laparoscopic ovariectomy with 3-mm minilaparoscopic instrumentation using a 3-port technique was feasible in guinea pigs.

CLINICAL SIGNIFICANCE

Laparoscopic ovariectomy can be considered as an alternative to open ovariectomy as an elective surgical technique to prevent reproductive disorders in guinea pigs.

Choice of Repairing Inguinal Hernia in Children: Open Versus Laparoscopy

Inguinal hernia is a common disorder of childhood that requires surgical repair at diagnosis. Traditionally, it is operated upon by open inguinal incision. However, with the introduction of laparoscopic repair in 1990, opinion of scientific community is divided concerning the best method of pediatric herniotomy. Educated parents, who long to have the choicest of the best, often gather information from internet and prefer to discuss their concerns with primary care physicians. This descriptive review is intended to provide practicing pediatricians with updated evidence-based information which will enable them to counsel parents regarding the choice of hernia repair. Based on careful analysis of current literature, unacceptable standards are defined in this paper and rationalized recommendations are proposed. Laparoscopy appears to be beneficial in bilateral hernia of girls, giant hernia, recurrence following failed open repair and in hernia associated with undescended testis or ambiguous genitalia. On the other hand, open herniotomy appears to be advantageous in male inguinal hernia, unilateral female hernia, premature newborns, failed laparoscopic repair and in hernia associated with serious co-morbidity.