Suction instrument with varying inner diameter

A suction instrument, comprising:

• (a) a grip portion comprising a suction port and a plurality of distally facing step-down surfaces, wherein the grip portion defines a first lumen and a proximal step-down lumen terminating into a proximal end, wherein the proximal step-down lumen is in communication with the first lumen, wherein the first lumen has a first diameter, wherein the proximal step-down lumen has an array of diameters that decrease in size toward the proximal end due to the plurality of distally facing step-down surfaces, wherein at least one diameter in the array of diameters is smaller than the first diameter;
• and
• (b) a cannula extending distally from the grip portion, wherein the cannula defines a second lumen in fluid communication with the first lumen of the grip portion, wherein the cannula comprises:
• (i) a proximal portion connected to the grip portion, wherein the proximal portion of the cannula defines a first portion of the second lumen, wherein the first portion of the second lumen has a first cross-sectional area, and
• (ii) a distal portion terminating into an open distal end, wherein the distal portion of the cannula defines a second portion of the second lumen, wherein the second portion of the second lumen has a second cross-sectional area, wherein the second cross-sectional area is smaller than the first cross-sectional area.