Laparoscopic splenectomy: posterior approach

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摘要

The description of the laparoscopic splenectomy: posterior approach covers all aspects of the surgical procedure used for the management of benign pathologies of the spleen.
Operating room set up, position of patient and equipment, instruments used are thoroughly described. The technical key steps of the surgical procedure are presented in a step by step way: exploration, mobilization, dissection, division, extraction.
Consequently, this operating technique is well standardized for the management of this condition.

媒體類型

刊物

2001-03

普通的

最愛

音訊

數位出版

WeBSurg.com, Mar 2001;1(03).
URL: http://www.websurg.com/doi-ot02en198a.htm

Laparoscopic splenectomy: posterior approach

1. Introduction

Laparoscopic splenectomy (LS) is a demanding operation which is not yet performed routinely, even though certain surgeons now consider it a standard technique for benign pathologies of the spleen. Compared to other laparoscopic procedures, manipulation of the spleen can be problematic, due to its location and size. Control of bleeding may also be a problem, because of the rich vasculature of the spleen. The posterior approach described as follows offers a safer access to the splenic vessels.

2. Anatomy

• Spleen

The spleen plays both a major role in the functioning of the immune system and as the regulator of red blood cell formation. These 2 main functions of the spleen were not discovered until the beginning of the twentieth century.
The spleen is the most vascularized organ in the body, its parenchyma is fragile, and splenectomy is often performed for bleeding disorders, all of which increase the risk of uncontrollable hemorrhage during laparoscopy. In addition, it is attached by several ligaments to other intra-abdominal organs or anatomical structures. Perfect understanding of the anatomy of the spleen and surrounding structures is therefore mandatory for a successful procedure.

• Topography

• Location

The spleen is situated in the left upper abdominal quadrant.
The axis of the spleen corresponds to the axis of the 10th left rib. Depending on the patient's morphological type, this axis may vary. In obese and/or patients with short limbs, the position of the spleen is high, deep and almost horizontal.

• Diaphragmatic surface

The diaphragmatic or posterior external surface is convex and entirely covered with peritoneum.

• Renal surface

The renal or inferior internal surface is concave, faces downwards and inwards and is covered with peritoneum.
The superior pole or posterior superior surface is curved and lies in the region of the 10th intercostal space.

• Gastric surface

The gastric or anterior internal surface is concave, faces inwards and contains the splenic hilum.

• Colonic surface

The colonic or anterior inferior surface (the base of the spleen's irregular pyramid shape) is slightly concave, and faces caudally, medially and slightly anteriorly.

• Ligaments

• Pancreaticosplenic

The spleen remains fixed in the left hypochondrium to neighboring anatomical structures by ligaments.
1. The pancreaticosplenic ligament attaches the posterior margin of the hilum to the tail of the pancreas and to the splenic vessels on the lower renal surface of the spleen. This peritoneal fold is referred to as the mesentery of the spleen. It ranges from 3 to 8 cm in length. The longer the ligament is, the easier the splenectomy will be to perform.

• Gastrosplenic

2. The gastrosplenic ligament attaches the anterior margin of the hilum to the greater curvature of the stomach, on the gastric surface of the spleen. It contains the short gastric vessels and the gastroepiploic artery, which are branches of the splenic artery.

• Phrenicosplenic

3. The phrenicosplenic ligament extends from the diaphragm and the anterior aspect of the left kidney to the superior pole of the hilum on the upper diaphragmatic surface of the spleen.

• Splenocolic

4. The splenocolic ligament attaches the base of the hilum to the left transverse mesocolon and to the left splenic flexure, on the colonic surface of the spleen.

• Phrenicocolic

5. The phrenicocolic ligament is a triangular fold of peritoneum attaching the left flexure of the colon and the diaphragm to the lower extremity of the spleen.

3. Indications

Indications
- idiopathic thrombocytopenic purpura (ITP);
- autoimmune hemolytic anemia;
- microspherocytosis;
- benign tumors and cysts;
- HIV-related thrombocytopenia.

Relative contraindications
- hematological malignancies;
- moderate splenomegaly (<1200g).

Absolute contraindications
- massive splenomegaly,
- portal hypertension.

4. Preop period

Preoperative investigations include:
- a complete blood count (CBC);
- a coagulation profile;
- an abdominal ultrasound to evaluate the size of the spleen;
- an abdominal CT scan in case of abnormal laboratory values to check for the absence of lymph nodes in the splenic hilum.

Cortisone therapy should be restricted to a minimum, to limit the risk of infectious complications.
If there is no coagulopathy, the minimum platelet count should be 40 000. Below this count, IV immunoglobulins must be administered during the three days preceding the operation. If this treatment is not effective, it is possible to operate with a lower platelet count (20 000) if there is no associated coagulation disorder.

5. Operating room set-up

• Patient

The patient is placed in right lateral decubitus, flexed at the waist.
A cushion is placed under the contra-lateral lumbar fossa which opens the operative field, thereby facilitating trocar placement.

• Team

The surgeon stands facing the patient.
The assistant stands behind the patient's head.
They are both able to view separate video monitors.

• Equipment

1. Operating table
2. Anesthetic equipment
3. Laparoscopic unit
4. Video monitors
5. Electrocautery
6. Instrument table

6. Trocar placement

• Principles

A 13 mm Hg pneumoperitoneum is established by the usual technique.
In most cases, only 3 trocars are necessary.

• Optical

Laparoscopes: 0° and 30°
The 10 mm trocar through which the laparoscope is to be introduced, is inserted in the left hypochondrium, halfway between the umbilicus and the left costal margin.

• Operating

Finally, a 12 mm trocar is introduced into the left lumbar fossa, on the posterior axillary line, far enough from the anterior superior iliac spine not to be hindered by the pelvis while manipulating the instruments.
Particular care should be taken during introduction of this trocar because of the proximity of the iliac colon.
Through this trocar, which is equipped with a universal converter, the dissection instruments, the clip applier, the ultrasonic dissectors and the endoscopic stapler are inserted.

• Retractors

A 5 mm trocar, is placed under the left costal margin, 10 cm from the xiphoid process. It is intended for insertion of a peanut swab or atraumatic graspers, used to manipulate the spleen.

7. Instrumentation

• Optical devices

2 devices are used:
- a direct view lens (10 mm 0°) for most of the dissection,
- an angle view lens (10 mm 30°) for the dissection of short vessels.

• Operating devices

Ultrasonic dissectors or bipolar forceps
Both enable the surgeon to achieve hemostasis of the inferior polar vessels and of the short vessels without having to use clips.

• Retractors

• Others

Specimen retrieval bags are recommended.
Some of these bags are often too small.
However, those which can contain large spleens require a 15 mm trocar.

8. Exploration

• Abdominal cavity exploration

The videoscopic equipment allows for a full exploration of the abdominal cavity.
The mobility of the spleen and possible adhesions surrounding the spleen should be assessed during this step.

• Associated pathologies

The absence of an associated or generalized pathology must be verified, as well as the absence of a secondary spleen, which might be visible before dissection.

9. Mobilization

• Positioning

By placing the patient in lateral decubitus position, the spleen is tipped forward.

• Division/inferior polar vessels

The first operative step is to dissect free the splenic flexure and to control the inferior polar vessels which are dissected one by one until the main vessels in the splenic hilum can be seen. The exposure for this step is carried out using an atraumatic grasper which retracts the fatty strip of tissue, usually found on the lower tip of the spleen, upward and forward.
Hemostasis is achieved with ultrasonic dissectors.

• Posterior mobilization

Due to its weight, the spleen usually tips forward easily, progressively exposing the phrenicosplenic ligament and then the splenorenal ligament. The posterior adhesions with the diaphragm are dissected free with a coagulating or ultrasonic hook, before incision of the spleno-renal ligament caudad to cephalad.

10. Dissection

• Principles

Throughout this dissection, it is important to remain constantly in contact with the spleen in order to avoid going accidentally behind the pancreas. When the tail of the pancreas is close to the splenic hilum, dissection should be performed between the posterior edge of the spleen and the anterior surface of the pancreas.

• Posterior dissection

• Principles

Completely dissecting free the splenorenal ligament from the spleen gives access to the splenic vessels whose posterior surface is visible.
If necessary, the spleen may be tilted backwards to expose the anterior surface of the vessels.

• Splenic vessels

It is essential to sufficiently isolate the vessels, in order to facilitate subsequent passage of the stapler.
These sometimes voluminous vessels follow an oblique course, from back to front and upwards, starting at the posterior superior margin of the tail of the pancreas. Their course in the pancreaticosplenic ligament can be very short, which accounts for the difficulty of dissecting free the origin of the pedicule of these vessels.

• Short vessels

Towards the top of the spleen, the short gastrosplenic vessels are also skeletonized at their origin. At this point the vessels are not yet divided. If they were, the spleen would become too mobile.

11. Division

• Principles

Once this dissection is completed, the inferior displacement of the spleen naturally exposes all of the gastric fundus, especially its posterior surface. It is thus possible to safely control the short vessels which become taut without having to use an instrument to retract the greater curvature.

• Division/short vessels

Using ultrasonic dissectors, division and hemostasis of the gastrosplenic vessels are achieved first, in order to improve the access to the splenic vessels.

• Division/splenic vessels

The spleen is now only held in place by the splenic artery and vein. By placing the jaws of a dissector or of an atraumatic grasper on either side of the pedicle, the spleen is lifted up from its bed. In cases where the spleen is hypertrophied and/or heavy, a ring-shaped retractor is used. An endoscopic stapler, loaded with 2.5 mm vascular staples, is used to staple the pedicle to the splenic hilum.

12. Extraction

The spleen is placed in a specimen retrieval bag introduced through a 15 mm trocar, which replaces the 12 mm trocar.

13. End/procedure

The splenic bed is washed. It is usually not necessary to drain the splenic bed.
The pneumoperitoneum is evacuated after removing the various trocars under visual control. Trocar sites of 10 mm and larger are sutured, the deep muscular level with absorbable thread followed by the superficial level. Depending on the surgeon's preference, the spleen is either morcellated in the bag, or extracted through a small Pfannenstiel incision.

14. Postop period

If there is a drain, it is removed the day after the operation. Oral diet may be resumed on the day of surgery, and the patient is discharged between 3 to 5 days following the surgery.

15. Conclusion

By decreasing the number of trocars, the posterior approach simplifies the technique of laparoscopic splenectomy and makes it safer at the same time.

16. Reference

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